How to check abs on an accent. Anti-lock braking system. Prices are not high everywhere

Diagnosis of ABS failures

ABS warning lamp connection diagram

The driver is notified of ABS failures by a special warning lamp located on the vehicle’s instrument panel. As soon as the ABS control module detects a violation in the system, it turns it off. The brake system continues to function as usual.

Diagnosis of the ABS condition is carried out every time the engine is started and is accompanied by a short-term activation of the warning lamp. Within a short time after starting, the llama should automatically turn off.

If the ABS warning light comes on and stays on while driving, first make sure that the parking brake is fully released and that the brake system is functioning properly. If everything is normal, then the ABS has failed. First of all, perform the following simple checks:

a) Check the condition of the brake calipers and wheel cylinders;
b) Check the condition and reliability of fastening of the electrical wiring connectors of the ABS control module and wheel sensors (see Chapter Onboard electrical equipment);
c) Check the relevant fuses (see Chapter Onboard electrical equipment).

ABS warning lamp failures

The cause of failure of the ABS warning lamp may be a break or short circuit in its electrical wiring.

The ABS warning lamp does not activate when the ignition is turned on

Try to turn on the ignition without starting the engine - if the other indicator lamps included in the instrument cluster work properly, proceed to the next step of the test, otherwise you should carry out the necessary restoration of the instrument panel.

Turn off the ignition. Remove the instrument cluster, remove the ABS warning lamp and check its condition. If the lamp is burnt out, replace it, otherwise proceed to the next step of the test.

Disconnect contact pair B62/F45 and measure the voltage between chassis ground (-) and terminal No. G6 (+) of connector B62. If the measurement result is less than 3 V, proceed to the next test step, otherwise, check the condition of the wiring of the corresponding warning lamp. Carry out the necessary restorative repairs.

Turn off the ignition, place the indicator lamp being tested in its normal place and install the instrument cluster.

Turn on the ignition and repeat the voltage measurement. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the electrical wiring. Carry out the necessary restorative repairs.

Turn off the ignition and check the voltage between terminal G6 (+) of connector F45 and chassis ground. If the measurement result is less than 3 V, proceed to the next test step, otherwise check the condition of the related wiring. Carry out the necessary restorative repairs.

Turn on the ignition and repeat the test. If the measurement result is less than 3 V, proceed to the next test step, otherwise, check the condition of the wiring of the corresponding warning lamp. Carry out the necessary restorative repairs.

Measure the resistance between terminal No. 23 of connector F49 and ground. If the measurement result is less than 5 ohms, proceed to the next test step, otherwise check the condition of the grounding of the control module/hydraulic modulator assembly. Carry out the necessary restorative repairs.

Measure the resistance between ground and terminal G6 of connector F45. If the measurement result is less than 5 ohms, proceed to the next test step, otherwise check the condition of the connector and its wiring harness. Carry out the necessary repairs and replace the connector if necessary.

Turn off the ignition and check the condition of the contact connectors on the circuit section between the instrument cluster and the ABS control module - if there are no signs of poor contact reliability, replace the ABS control module/hydraulic modulator assembly.

The ABS warning light does not turn off after the engine is started

Turn off the ignition and make sure that the contact connector of the control module/ABS hydraulic modulator is completely seated and securely fixed.

Measure the resistance between chassis ground and each (A and B) of the diagnostic terminals (B81). If the measurement result is less than 5 ohms, proceed to the next step of the test, otherwise check the condition of the relevant wiring harness and make the necessary repairs.

Turn off the ignition and connect the diagnostic terminal to terminal No. 8 of the B82 diagnostic connector. Disconnect the ABS control module connector and measure the resistance between terminal No. 4 of connector F49 and chassis ground. If the measurement result is less than 5 ohms, proceed to the next step of the test, otherwise check the condition of the electrical wiring in the circuit between the ABS control module and the diagnostic connector, and make the necessary repairs.

Run the engine at idle speed and check the voltage between the B (+) terminal on the rear of the generator (power terminal) and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise replace/repair the generator (see Chapter) and repeat the test.

Turn off the ignition and check the condition of the battery pole terminals and the reliability of the wire terminal lugs on them. If necessary, make the necessary corrections.

Disconnect the ABS control module wiring connector, then run the engine at idle speed and measure the voltage between terminal No. 1 (+) of connector F49 and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the power supply circuit wiring. Carry out the necessary restorative repairs.

Disconnect contact pair B62/F45 and turn on the ignition - if the ABS warning lamp does not work, proceed to the next step of the test, otherwise check the condition of the front wiring harness.

Turn off the ignition and check the condition of the tabs on the control module connector terminals. If the terminals are in order, proceed to the next step of checking, otherwise replace the control module/hydraulic modulator (see Section).

Measure the resistance between terminals No. 22 and 23 of the ABS control module connector. If the measurement result is more than 1 MOhm, proceed to the next test step, otherwise replace the ABS control module/hydraulic modulator assembly (see Section Removing, installing and checking the proper functioning of the ABS control module/hydraulic modulator assembly).

Measure the resistance between terminal G6 of connector F45 and chassis ground. If the measurement result is less than 0.5 Ohm, proceed to the next step of the test, otherwise make the necessary repairs to the electrical wiring.

Connect the wiring harness to the ABS control module and measure the resistance between terminal G6 of connector F45 and chassis ground. If the measurement result is more than 1 MOhm, proceed to the next step of the test, otherwise make the necessary repairs to the electrical wiring.

Check the condition and tightness of the ABS control module connector. If necessary, make the necessary corrections or replace the control module/hydraulic modulator unit.

Unable to read fault codes

If the warning lamp turns on and off normally, but does not display the initial code (DTC 11 - see below) when entering diagnostic mode, turn the ignition switch off and perform the checks.

Wheel sensor failures

Failures of wheel sensors lead to disruption of ABS functioning. The connection diagram for wheel sensors is shown in the illustration.

An open circuit in the wheel sensor circuit or an excessively high input voltage level (DTC Nos. 21, 23, 25 and 27)

Disconnect the wiring harness from the ABS control module and measure the voltage between the appropriate wheel sensor terminal No. 1 and chassis ground. If the measurement result is less than 1 V, proceed to the next test step, otherwise replace the sensor.

Turn the ignition on and repeat the previous check. If the measurement result is less than 1 V, proceed to the next test step, otherwise replace the sensor.

Turn off the ignition and connect the electrical wiring to the sensor. Measure the resistance between terminals Nos. 11 and 12 (DTC 21)/9 and 10 (DTC 23)/14 and 15 (DTC 25)/7 and 8 (DTC 27) of connector F49. If the measurement result does not fall outside the range of 1 ÷ 1.5 kOhm, proceed to the next step of the test, otherwise check the condition of the electrical wiring in the area between the control module and the sensor. Carry out the necessary restorative repairs.

Measure the voltage between ground and terminal No. 11 (DTC 21)/9 (DTC 23)/14 (DTC 25)/7 (DTC 27) of connector F49. If the measurement result is more than 1 V, eliminate the cause. short circuit on the circuit section between the sensor and the ABS control module. If there is no voltage (less than 1 V), turn on the ignition and repeat the test. If there is still no voltage (less than 1 V), proceed to the next test step, otherwise check the condition of the wiring between the sensor and the ABS control module, and if necessary, eliminate the cause of the short circuit.

Measure the gap between the sensor and the rotor along the entire perimeter of the latter. If there is insufficient clearance (see Specifications) adjust it by selecting the adjusting shim (26755AA000). If the gap is too large, remove the spacers and replace the rotor (complete with hinge assembly) or the failed sensor. Having completed the adjustment, proceed to the next step of testing.

Turn off the ignition and measure the resistance between terminal No. 1 of the wheel sensor connector and chassis ground. If the measurement result is more than 1 MΩ, proceed to the next test step, otherwise replace the sensor.

Turn off the ignition and connect the electrical wiring to the wheel sensor. Measure the resistance between chassis ground and terminal No. 11 (DLC 21)/9 (DLC 23)/14 (DLC 25)/7 (DLC 27) of connector F49. If the measurement result is more than 1 MOhm, proceed to the next step of the test, otherwise check the condition of the wiring in the circuit between the sensor and the ABS control module. Carry out the necessary restorative repairs. If the wiring is OK, replace the control module/hydraulic modulator assembly.

Restore the original connections of all connectors, clear the processor memory (see below) and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, proceed to perform the appropriate check. If the failure does not recur, therefore, the malfunction was temporary, once again make sure that all contact connections are securely fastened.

Short circuit in the wheel sensor circuit (DTC No. 22, 24, 26 and 28)

Turn off the ignition and check that the sensor mounting bolts are securely tightened (32 Nm). If necessary, tighten the fasteners and proceed to the next step of testing.

If you are unable to use an oscilloscope, proceed to checking the mechanical condition of the rotor and cleaning the components.

If you have an oscilloscope, jack up the car and place it on jack stands so that the wheels are completely off the ground. Turn off the ignition and connect an oscilloscope between terminals No. C5 (+) and B5 (-) (DTC 22)/C6 (+) and B6 (-) (DTC 24) of connector B62 or 1 (+) and 2 (-) (DTC 26)/4 (+) and 5 (-) (DTC 28) connectors F55.

Turn on the ignition and, while rotating the corresponding wheel of the car, monitor the oscilloscope readings. The amplitude of the sinusoidal signal displayed on the screen should not exceed the range of 0.12 ÷ 1.00 V; if this condition is not met, or the signal has an incorrect shape, proceed to the next stage of testing.

Check the wheel hub runout. If the measurement result is less than 0.05 mm, proceed to the next test step, otherwise replace the hub.

Turn off the ignition. Disconnect the wiring from the appropriate wheel sensor. Measure the resistance between terminals No. 1 and 2 of the sensor connector. If the measurement result does not fall outside the range of 1 ÷ 1.5 kOhm, proceed to the next test step, otherwise replace the sensor.

Measure the resistance between ground and terminal No. 1 of the wheel sensor connector. If the measurement result is more than 1 MΩ, proceed to the next test step, otherwise replace the sensor.

Connect the wiring to the wheel sensor and disconnect it from the ABS control module. Measure the resistance between terminals Nos. 11 and 12 (DTC 22)/9 and 10 (DTC 24)/14 and 15 (DTC 26)/7 and 8 (DTC 28) of ABS control module connector F49. If the measurement result does not fall outside the range of 1 ÷ 1.5 kOhm, proceed to the next step of the test, otherwise carry out the necessary repairs to the electrical wiring in the circuit section between the sensor and the ABS control module/hydraulic modulator.

Measure the resistance between chassis ground and terminal No. 11 (DTC 22)/9 (DTC 24)/14 (DTC 26)/7 (DTC 28) of control module connector F49. If the measurement result is more than 1 MΩ, proceed to the next test step, otherwise check the wiring between the sensor and the module for a short circuit. Carry out the necessary restorative repairs.

Measure the resistance between ground and terminal No. 23 of connector F49. If the measurement result is less than 0.5 Ohm, proceed to the next stage of testing, otherwise eliminate the cause of the grounding quality problem.

Check the tightness of the contact connectors of the ABS control module and the wheel sensor. Make any necessary corrections. If the contacts are OK, proceed to the next step of the test.

Make sure the car phone/remote control transmitter is installed far enough away from the wheel sensor wiring harness.

Restore the original connections of all contact connectors and measure the resistance between ground and terminal No. A5 (DTC 22)/A6 (DTC 24) of connector B62. If the measurement result is less than 0.5 Ohm, proceed to the next test step, otherwise replace the shielded harness.

Restore the original connections of all connectors and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, go to the appropriate test. If the failure does not recur, therefore, the malfunction was temporary, once again make sure that all contact connections are securely fastened.

There are problems related to the proper operation of the wheel sensor (one or all four) issuing an information signal (DTC 29)

Assess the condition of the treads and tire inflation pressure. If necessary, make appropriate corrections/replacements.

Check that the ABS sensor mounting bolts are securely tightened (32 Nm). If necessary, tighten the fasteners and proceed to the next step of testing.

Measure the gap between the sensor and the rotor along the entire perimeter of the latter. If the gap is insufficient (see Specifications), correct it by selecting an adjusting shim (26755AA000). If the gap is too large, remove the spacers and replace the rotor (complete with hinge assembly) or the failed sensor. Having completed the adjustment, proceed to the next step of testing.

If you are unable to use an oscilloscope, proceed to checking the mechanical condition of the rotor and cleaning the components. If you have an oscilloscope, jack up the car and place it on jack stands so that the wheels are completely off the ground. Turn off the ignition and connect an oscilloscope between terminals No. C5 (+) and B5 (-) (DTC 22)/C6 (+) and B6 (-) (DTC 24) of connector B62 or 1 (+) and 2 (-) (DTC 26)/4 (+) and 5 (-) (DTC 28) connectors F55.

Carefully inspect the wheel sensor and its rotor for signs of damage or contamination. Clean the components and troubleshoot any problems.

Check the wheel hub runout. If the measurement result is less than 0.05 mm, proceed to the next test step, otherwise replace the hub.

Turn off the ignition. Restore the original electrical wiring connections. Clear the processor memory (see below) and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, go to the appropriate test. If the failure does not recur, therefore, the malfunction was temporary, check again that all contact connections are securely fastened.

ABS control module/hydraulic modulator failures

Malfunction of the intake (DTC 31, 33, 35 and 37)/exhaust (DTC 32, 34, 36 and 38) solenoid valve

Disconnect the wiring from the ABS control module.

Run the engine at idle speed and measure the voltage between terminal No. 1 (+) of the control unit connector F49 and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the electrical wiring between the battery, ignition switch and ABS control module. Carry out the necessary restorative repairs.

Turn off the ignition and measure the resistance between chassis ground and terminal No. 23 of connector F49. If the measurement result is less than 0.5 Ohm, proceed to the next stage of testing, otherwise eliminate the cause of the grounding quality problem.

Malfunction of the ABS control module (DTC 41)

Turn off the ignition. Disconnect the wiring from the ABS control module and measure the resistance between terminal No. 23 of connector F49 and chassis ground. If the measurement result is less than 0.5 Ohm, proceed to the next stage of testing, otherwise eliminate the cause of the grounding quality problem.

Check the condition and reliability of fixation of the electrical wiring contact connectors on the ABS control module, generator and battery. If necessary, carry out appropriate repairs. If there are no contact quality violations, proceed to the next stage of testing.

Make sure the car phone/remote control transmitter is installed well away from the ABS wiring harnesses.

Turn off the ignition. Restore the original electrical wiring connections. Clear the processor memory and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, go to the appropriate test. If the failure does not recur, therefore, the malfunction was temporary, once again make sure that all contact connections are securely fastened.

Deviation from the nominal supply voltage level (DTC 42)

Start the engine and warm it up to normal operating temperature. Check that the speed is set correctly idle move. Measure the voltage between the B (+) terminal on the rear of the generator and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 17 V, proceed to the next step of the test, otherwise check the condition of the charging system (see Chapter Engine electrical equipment ), make the necessary corrections.

Turn off the ignition and check the condition of the battery pole terminals and the reliability of the wire terminal lugs on them. If necessary, clean the contact surfaces of the terminals/tips. If the terminals are OK, disconnect the wiring from the ABS control module, run the engine at idle speed and measure the voltage between ground and terminal No. 1 (+) of connector F49. If the measurement result does not fall outside the range of 10 ÷ 17 V, proceed to the next step of the test, otherwise check the condition of the wiring between the ignition switch and the contact connector of the ABS control module. Carry out the necessary restorative repairs.

Turn off the ignition and measure the resistance between terminal No. 23 of connector F49 and chassis ground. If the measurement result is less than 0.5 Ohm, proceed to the next stage of testing, otherwise eliminate the cause of the grounding quality problem.

Check the condition and reliability of fixation of the electrical wiring connectors on the ABS control module, generator and battery. If necessary, carry out appropriate repairs. If there are no contact quality violations, proceed to the next stage of testing.

Turn the ignition switch OFF and disconnect the two transmission control module (TCM) wiring connectors. Also disconnect the wiring from the ABS control module. Measure the resistance between terminal No. 3 of connector F49 and chassis ground. If the measurement result is more than 1 MOhm, proceed to the next test step, otherwise, repair the wiring in the area between the TCM and the ABS control module.

Turn on the ignition and measure the voltage between ground and terminal No. 3 of connector F49. If the measurement result is less than 1 V, proceed to the next test step, otherwise make the necessary repairs to the wiring in the area between the TCM and the ABS control module.

Measure the voltage between ground and terminals No. 3 and 31 of connector F49. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the wiring in the area between the ABS control module and the TCM. Carry out the necessary restorative repairs.

Check the condition and reliability of fixation of the contact connectors of the ABS and AT control modules. If necessary, clean the terminals and proceed to the next test step.

Valve relay malfunction (DTC 51)

Turn off the ignition and disconnect the electrical wiring from the ABS control unit. Run the engine at idle speed and measure the voltage between terminals No. 1 and 24 of connector F49 of the ABS control module and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the wiring between the ABS control unit and the battery. Carry out the necessary restorative repairs.

Measure the resistance between terminals No. 23 (+) and 24 (-) of the control module connector. If the measurement result is more than 1 MΩ, proceed to the next test step, otherwise replace the control unit.

Check the condition and reliability of fixation of the electrical wiring connectors on the ABS control module, generator and battery. If necessary, carry out appropriate repairs. If there is no violation of the quality of contacts, proceed to the next stage of testing.

Turn off the ignition. Restore the original electrical wiring connections. Clear the processor memory and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, go to the appropriate test. If the failure does not recur, therefore, the malfunction was temporary, once again make sure that all contact connections are securely fastened.

Malfunction of the drive motor/its relay (DTC 52)

Turn off the ignition. Disconnect the wiring harness from the ABS control module, then turn the ignition switch back to the ON position and measure the voltage between control module connector F49 terminal No. 25 and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise, repair the electrical wiring in the area between the battery and the control module/hydraulic modulator. Check the SBF fuse holder.

Turn off the ignition and measure the resistance between ground and terminal No. 26 of connector F49. If the measurement result is less than 0.5 Ohm, proceed to the next step of the test, otherwise, repair the control unit ground circuit.

Run the engine at idle speed and measure the voltage between terminal No. 1 of connector F49 and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the electrical wiring in the areas between the battery, ignition switch and ABS control module. Carry out the necessary restorative repairs.

Turn off the ignition and measure the resistance between ground and terminal No. 23 of connector F49. If the measurement result is less than 0.5 Ohm, proceed to the next stage of testing, otherwise eliminate the cause of the grounding quality problem.

While checking the operating sequence of the hydraulic modulator valves (see Section Checking the actuation sequence of the ABS hydraulic modulator valves) Check by ear that the electric motor is functioning properly. If the motor rotates properly, proceed to the next test step, otherwise replace the ABS modulator/control unit assembly.

Check the condition and reliability of fixation of the electrical wiring contact connectors on the control module/ABS hydraulic modulator assembly, generator and battery. If necessary, carry out appropriate repairs. If there are no contact quality violations, proceed to the next stage of testing.

Check that the brake lights work properly when you depress the foot brake pedal. If everything is in order, proceed to the next step of the test, otherwise check the condition of the lamps and wiring of the brake light circuit.

Turn off the ignition. Disconnect the wiring from the ABS control module. Depress the foot brake pedal and measure the voltage between terminal No. 2 of the ABS control module connector F49 and chassis ground. If the measurement result does not fall outside the range of 10 ÷ 15 V, proceed to the next step of the test, otherwise check the condition of the electrical wiring in the area between the brake light sensor-switch and the ABS control module. Carry out the necessary restorative repairs.

Check the condition and reliability of fixation of the contact connectors of the sensor switch and the control unit. If necessary, make appropriate corrections. If the contacts are OK, proceed to the next step of the test.

Malfunction of the G-sensor output signal (DTC 56)

Check the markings of the ABS control module/hydraulic modulator assembly - the code is applied to the surface of the block between the hydraulic line connection fittings and for models (see Specifications). If the marking corresponds to the configuration of your car, proceed to the next step of the test, otherwise replace the ABS control module/hydraulic modulator assembly.

Turn off the ignition. Remove the center console (see Chapter Body). Unbolt the G-sensor without disconnecting the electrical wiring from it. Turn the ignition key back to the ON position and measure the voltage between terminals No. 1 (+) and 3 (-) with outside contact connector R70 of the sensor. If the measurement result does not fall outside the range of 4.75 ÷ 5.25 V, proceed to the next step of the test, otherwise check the condition of the electrical wiring in the area between the sensor and the ABS control module. Carry out the necessary restorative repairs.

Turn off the ignition. Disconnect the wiring from the ABS control module and measure the resistance between terminals No. 6 and 28 of connector F49 of the control module. If the measurement result does not fall outside the range of 4.3 ÷ 4.9 kOhm, proceed to the next stage of the test, otherwise carry out the necessary repairs to the electrical wiring in the area between the sensor and the ABS control module.

Disconnect the wiring from the G-sensor. Measure the resistance between terminal No. 6 of connector F49 and chassis ground. If the measurement result is more than 1 MOhm, proceed to the next step of the test, otherwise make the necessary repairs to the wiring in the area between the sensor and the ABS control module.

Measure the voltage between terminal No. 6 of connector F49 and chassis ground. If the measurement result is less than 1 V, proceed to the next step of the test, otherwise make the necessary repairs to the wiring in the area between the sensor and the ABS control module.

Repeat the last check with the ignition on. If the measurement result is less than 1 V, proceed to the next step of the test, otherwise make the necessary repairs to the electrical wiring in the area between the sensor and the ABS module.

Measure the resistance between ground and terminal No. 28 of connector F49. If the measurement result is more than 1 MOhm, proceed to the next step of the test, otherwise make the necessary repairs to the wiring in the area between the sensor and the ABS control module. If the wiring is OK, replace the control module/hydraulic modulator assembly.

Turn off the ignition and, without disconnecting the electrical wiring, unscrew the G-sensor. Check the secure fit of the contact connectors of the sensor and the ABS control module. Turn on the ignition and measure the voltage between terminals No. 2 (+) and No. 3 (-) of the R70 sensor connector. If the measurement result does not fall outside the range of 2.1 ÷ 2.4 V, proceed to the next test step, otherwise replace the sensor.

Tilt the sensor 90° forward and repeat the above check. If the measurement result does not fall outside the range of 3.7 ÷ 4.1 V, proceed to the next test step, otherwise replace the sensor.

Tilt the sensor at an angle of 90° back and repeat the test. If the measurement result does not fall outside the range of 0.5 ÷ 0.9 V, proceed to the next test step, otherwise replace the sensor.

Turn off the ignition. Check the condition and tightness of the contact connectors of the G-sensor and the ABS module. If necessary, carry out appropriate repairs. If the contact connections are OK, proceed to the next test step.

Restore the original electrical wiring connections. Clear the processor memory and repeat the procedure for reading diagnostic codes. If no changes (for improvement) have occurred, replace the ABS control module/hydraulic modulator assembly. If new codes appear, go to the appropriate test. If the failure does not recur, therefore, the malfunction was temporary, once again make sure that all contact connections are securely fastened.

Checking ABS Control Module I/O Signals

Map of the location of the contact terminals in the control module/hydraulic modulator connector and diagram electrical connections ABS components are shown in the illustrations.

ABS wiring diagram

1 - Control module assembly/ABS hydraulic modulator
2 - Control module
3 - Valve relay
4 - Electric motor relay
5 - Electric motor
6 - Inlet solenoid valve left front wheel
7 - Left front wheel exhaust solenoid valve
8 - Right front wheel inlet solenoid valve
9 - Right front wheel exhaust solenoid valve
10 - Left rear wheel inlet solenoid valve
11 - Left rear wheel exhaust solenoid valve
12 - Right rear wheel inlet solenoid valve

13 - Right rear wheel exhaust solenoid valve
14 - TCM (models with AT)
15 - Diagnostic connector
16 - DLC connector
17 - ABS warning lamp
18 -
19 - Stop light
20 - G-sensor
21 - Left front wheel sensor
22 - Right front wheel sensor
23 - Left rear wheel sensor
24 - Right rear wheel sensor

Map of the location of the contact terminals in the ABS control module connector
The shape of the signal taken from the individual terminals of the ABS sensors is shown in Resistance. illustrations. The list of signals is given in the table.

Reading ABS Trouble Codes (DTCs)

For a list of ABS DTCs, see Specifications on this Chapter.

Reading DTCs Using SSM

Prepare the SSM reader for operation.

Connect the diagnostic cable to the SSM and refill the cartridge.

Connect the SSM diagnostic cable to the DLC connector located on the left under the vehicle's instrument panel.

Turn the ignition key to the ON position (do not start the engine) and turn on the power to the SSM.

In the main menu (“Main Menu”) of the reader screen, select the section (Each System Check) and press the YES key.

In the “System Selection Menu” field of the screen, select the subsection (Brake Control System), confirm the selection by pressing the YES key.

After displaying information about the ABS type, press the YES key again.

In the “ABS Diagnosis” field of the screen, select the item (Diagnostic Code(s) Display) and confirm the selection by pressing the YES key.

In the “Diagnostic Code(s) Display” field of the screen, select (Current Diagnostic Code(s)) or (History Diagnostic Code(s)), press the YES key.

Reading current data

Enter the menu subsection (Brake Control System), wait for the message about the ABS type to appear on the screen and press the YES key.

In the “Brake Control Diagnosis” field of the screen, select the item (Current Data Display & Save) and confirm the selection by pressing the YES key.

In the Data Select Menu field, select (Data Display) and press YES.

Use the scroll buttons to navigate through the list displayed on the screen to select the data you are interested in. The list of output data is given in the table below.

Monitor screen	Output type	Units
Speed corresponding to the rotation speed of the right front wheel	Data output from the right front wheel sensor	km/h or mph
Speed corresponding to the rotation speed of the left front wheel	Left front wheel sensor data	km/h or mph
Speed corresponding to the rotation speed of the right rear wheel	Data output from right rear wheel sensor	km/h or mph
Speed corresponding to the rotation speed of the left rear wheel	Data output from left rear wheel sensor	km/h or mph
Brake light switch	Sensor-switch status	On or Off
Brake light switch	The voltage of the brake light sensor-switch is output
G-sensor input	G-sensor signal voltage (vehicle acceleration data)
Valve relay signal	Valve relay signal	On or Off
Motor relay signal	Motor relay signal	On or Off
ABS signal to TCM	Signal issued by the ABS control module to the TCM AT	On or Off
ABS warning lamp	Output of data on the operation of the ABS warning lamp	On or Off
Motor relay monitoring	Output of data on activation of the electric motor relay	High or low
Valve relay monitoring	Valve relay activation output	On or Off
SSM signal	ABS operating signal issued by the ABS control module to the AT TCM	On or Off

Reading DTCs without SSM

Remove the diagnostic connector located next to the driver's seat heater unit.

Turn off the ignition and connect the diagnostic terminal to terminal No. 8 of the connector.

Turn on the ignition, the ABS warning lamp will go into diagnostic mode and begin flashing fault codes (DTCs) stored in the processor memory.

The check start code (11) is always displayed first, then all other codes are displayed one by one, starting with the last one. After the last code is output, the cycle repeats for 3 minutes. Examples of code output are shown in the illustration. If there are no codes stored in the memory, the control lamp will only display the start code (11).

Removing codes from processor memory

Using SSM

In the main menu (“Main Menu”) of the SSM reader, select the item (2. Each System Check) and press the YES key.

In the System Select Menu field, select (Brake System), press YES, wait for the ABS type information to be displayed, then press YES again.

In the “Brake Control Diagnosis” field of the screen, select the item (Clear Memory) and confirm the selection by pressing the YES key.

Once the reader displays “Done” and “Turn ignition OFF”, remove power from the SSM and turn off the ignition.

Without SSM

After reading the DTCs output by the ABS warning lamp, disconnect the diagnostic terminal from terminal No. 8 of the diagnostic connector.

Within approximately 12 seconds, repeat the terminal connection/disconnection procedure three times with the duration of each phase (On and Off) of at least 0.2 s.

Successful completion of memory clearing is confirmed by the indicator lamp illuminating code 11.

The Anti-lock Braking System (ABS) controls hydraulic pressure on all four wheels during heavy braking and heavy braking. road surface, which prevents wheel locking. The cycle of braking and free rotation of the wheel occurs very quickly and continues until the car stops or until the brake pedal is released.

ABS advantages:

– ensures vehicle controllability with a high degree of reliability even during sudden braking;

– ensures the car stops during emergency braking while maintaining stability and controllability even when cornering.

If a malfunction occurs, a diagnostic function and a safety (backup) system are provided.

Anti-lock braking system

Element	Parameter	Nominal value	Note
ECU (electronic Control block)	Operating voltage, V Operating temperature, °C	10-16 40…+110	Combined ABS and EBD control unit
ABS warning lamp Brakes (EBD)	Operating voltage, V Current consumption, mA		Brakes: parking, brake fluid, EBD failure
HECU (hydraulic and electronic control unit)	Weight, kg Motor power, W Pump flow, cm 3 /s Battery capacity, cm 3 Operating voltage valves NO, NC, B	180 (12 V, 30 A) 2.1 (LPA) 6 (NRA)	NO normally open, NC normally closed, LPA battery low pressure, NPA - high pressure accumulator

Electronic Brake Force Distribution (EBD)

An EBD electronic brake force distribution device is installed in addition to the pressure regulator to ensure ideal distribution of brake fluid pressure to the front and rear wheel brakes. This prevents the rear wheels from locking when braking and provides increased braking performance.

Advantages of using electronic brake force distribution:

– functional improvement of the basic braking system;

– compensation of different coefficients of road adhesion;

– installation of a pressure regulator is not required;

– faults are determined using the monitoring system.

A comparison of the operation of the pressure regulator and electronic brake force distribution (EBD) is given in rice. 7.3.

Checking the voltage at the HECU hydraulic unit connector contacts

When checking the functionality of the anti-lock brake system, first of all it is necessary to check the voltage and resistance at the connector contacts of the HECU hydraulic unit, which must correspond to the values given in the table. 7.2.

Table 7.2

Voltage and resistance at the HECU hydraulic unit connector contacts

Contact no.	Description	State	Voltage output
	Voltage source AB 1. Power supply for solenoid valve	Constantly	On-board system voltage
	Ground connection	Always (in ABS control unit)
	Diagnostic connector contact (K-line)	Device connection Hi-Scan
			Resistance R=1275-1495 Ohm
	Left rear wheel speed sensor Left front wheel speed sensor Right front wheel speed sensor Right rear wheel speed sensor
	Power supply via switch ignition	Ignition on	High voltage detection V: 16 V
7, 11, 12, 13,14, 16, 21, 25	Not used
	Voltage source AB 2. Motor power supply	Constantly
	Ground connection - 2 (engine)	G07
	ABS relay control
	EBD relay control
	Brake light switch

Removing air from the hydraulic brake drive

This operation must be carried out to ensure that the ABS unit, brake pipes and master cylinder are properly bled and filled with brake fluid.

1. Remove the cap from the reservoir and fill with fresh brake fluid to the top mark of the reservoir. When removing air, make sure that the brake fluid level does not fall below the middle of the reservoir.

2. Place a clear plastic tube over the bleed screw and place the other end of the tube into a clear plastic container half filled with brake fluid (see Fig. rice. 7.1).

Rice. 7.4. Connecting the Hi-Scan device to the diagnostic connector

3. Connect the Hi-Scan device to the diagnostic connector located under the front panel ( rice. 7.4).

4. Select the operating mode according to the instructions on the Hi-Scan device screen:

– select the diagnostic mode for Hyundai vehicles;

– select the car name;

– select anti-lock braking system;

– select the air removal mode;

– press “YES” to operate the pump motor and solenoid valve;

– wait 60 seconds before starting to remove air (if this is not done, the engine may be damaged).

5. Press the brake pedal several times, then unscrew the bleed screw until fluid begins to flow out. Without releasing the pedal, tighten the bleed screw.

6. Repeat steps 5 for each wheel until there are no air bubbles in the escaping brake fluid.

7. Tighten the air bleeding screw to a torque of 7–9 Nm.

8. Repeat the described procedure for each wheel in the sequence indicated on rice. 7.2.

Troubleshooting

When the anti-lock braking system is operating, the phenomena listed in table may occur. 7.3, which are not malfunctions.

Table 7.3

Normal phenomena that may occur when the anti-lock brake system is operating

Phenomenon	Cause of occurrence
Knocks when checking the readiness of the brake system	When starting the engine, knocking noises can sometimes be heard from the engine compartment. This happens when checking the system operation and is not considered a deviation from the norm
Sound when ABS operates	1. From the engine inside the ABS hydraulic unit during operation (howling) 2. Appears along with vibration of the brake pedal (scraping sound) 3. When ABS is operating, the sound comes from the car chassis due to the cyclic action and release of the brakes (knocking - suspension, squeaking - tires)
ABS operation (long braking distance)	On uneven surfaces (snow and gravel roads), the braking distance for vehicles with ABS can sometimes be longer than for other vehicles. For this reason, you should drive on such roads at a reduced speed and be very careful.

Fault codes

Determining fault codes using the Hi-Scan device

1. Turn off the ignition.

2. Connect the Hi-Scan device to the diagnostic connector located under the front panel ( rice. 7.5).

3. Turn on the ignition.

4. Using the Hi-Scan tool, check for diagnostic codes.

5. After completing repairs or adjustments, erase the codes from memory.

6. Disconnect the Hi-Scan device.

Fault code table

Codes and causes of malfunctions, as well as elements that caused malfunctions, are given in table. 7.4.

Table 7.4

ABS brake system fault codes

Code malfunctions on the Hi+Scan device	Faulty elements	Cause malfunctions	Conditions definitions
S2 402	Engine relay. Engine (ECU, wiring harness)	Engine short circuit to battery Open circuit in engine	The controller starts monitoring the motor 1.8 s from the moment the motor relay turns off if the motor voltage is above the criterion for 200 ms The controller starts monitoring the engine after 1.8 s starting from the moment when the motor relay is switched off if the motor voltage is above the criterion for 200 ms
C1 102	Power circuit	Low voltage	1. When the ignition voltage is less than 9.4V for 500ms 2. If the voltage increases more than 9.6V, then the control returns to normal state 3. When the ignition voltage is less than 7.2V, detected in state 1 4. If the voltage increases more than 7.5V, the controller returns to state 1
C1 101		Overvoltage	1. When the ignition voltage is more than 16V for 500ms or more than 18 V for 49 ms 2. If the voltage returns to normal range, the controller resets
S1 604		EEPROM memory failure ECU malfunction	After the main processor writes the predetermined data into the EEPROM, reads the data, compares it with each other and determines that they are different from each other If the main/slave processor detects abnormal operation of RAM memory, register status, timer interrupts, AC/DC converter and cycle time
FL (front left wheel) - С1 202, FR (front right wheel) - С1 205, RL (rear left wheel) - C1 208, RR (rear right wheel) - C1 211		Long-term ABS mode	1. During the ABS control cycle, if the wheel moves at a speed of 2 km/h for more than 12 s 2. If the ABS control cycle continues for more than 36 seconds
S2 112	Valve Relay (ECU, Wire Harness)	Circuit break Short circuit	the valve is out of range and it continues within 56 ms When the valve relay turns on, the relay reference voltage valve higher than required and this continues for 56 ms
S1 604	Solenoid valve (ECU, wiring harness)	Open circuit, short circuit, current leaks	1. When the valve relay is turned off, the solenoid drive MOSFET reverse voltage is higher than required and this continues for 56 ms 2. When the valve relay turns on and the solenoid turns off, the reverse voltage of the solenoid drive transistor (MOSFET) is lower than required and this continues for 56 ms 3. When the valve relay and solenoid turn on, reverse the solenoid drive MOSFET voltage is higher than required and continues for 56 ms
S2 402	Engine relay. Engine (ECU, wiring harness)	Engine relay or fuse, open, engine short circuit to ground Engine lock	When the motor relay turns on, the motor reference voltage is lower than required and this continues for 49 ms The controller begins to monitor the motor voltage within 84 ms from the moment the motor relay turns off. If the motor voltage is below the required voltage for 49 ms after 1.8 s from the moment the motor is switched off, the motor is turned on again for 1 s and the specified test is repeated again. During the second test, when the motor voltage is below the required value for 49 ms, the controller recognizes a fault
FL (front left wheel) - C1 200, FR (front right wheel) - C1 203, RL (rear left wheel) - C1 206, RR (rear right wheel) - C1 209	Sensor (wires, active element, ECU)	Short circuit to ground; short circuit to battery; open circuit	The wheel speed is less than 7 km/h, the sensor bias voltage is outside the permissible limits (2.15-3.5 V), if it is with; standing continues for more than 140 ms
FL - C1 201, FR - C1 204, RL - C1 207, RR - C1 210		Speed jump	A wheel deceleration of -100 g (-25 km/h in 7 ms) causes the controller to start monitoring this value and compares the wheel speed with the speed of the car from the next cycle. When -100 g deceleration continues for more than 140 ms, the controller detects a fault
FL - C1 202, FR - C1 205, RL - C1 208, RR - C1 211		Large air gap	This control is carried out during the period when the minimum speed increases from 2 to 10 km/h. 1. When the minimum speed of a wheel is 2 km/h and the speed of other wheels exceeds 10 km/h with an acceleration greater than 0.4 g, the controller begins to compare the speeds of the wheels with each other. If the difference is below 4 km/h and continues for 140 ms 2. Except for case 1, when the minimum wheel speed is equal to 2 km/h, and the maximum wheel speed exceeds 10 km/h and this condition continues for 20 s
FL - C1 201, FR - C1 204, RL - C1 207, RR - C1 210		Active element is faulty	1. The maximum wheel speed exceeds 20km/h, the wheel speed is 40% of the maximum wheel speed. If this condition continues for 1 minute 2. The maximum wheel speed exceeds 40km/h, the wheel speed is 60% of the maximum wheel speed. If this condition continues for 30 s

Checking the ABS sensor output voltage

1. Raise the vehicle and release the parking brake lever.

2. Disconnect the connector from the HECU hydraulic unit and take measurements from the connector side located on the wire side. The connector contact numbers for checking the output voltage of the ABS sensors of the corresponding wheels are given in table. 7.5. The output voltage when measured using an oscilloscope is at least 100 mV.

Table 7.5

Connector pin numbers for checking the output voltage of ABS sensors

corresponding wheels

Front

left

wheel

Front

right

wheel

Rear

left

wheel

Rear

right

wheel

WARNING

Remove the double protection of the contact connectors and insert the meter probe into the contact connector from the side of the wiring harness (rear). When installing the probe from the contact side, it is difficult to ensure a reliable connection.

3. Disconnect the HECU and engine connector.

Installation

1. Installation is carried out in the reverse order of removal.

2. Tighten the modulator mounting bolts and brake pipe nuts to the specified torques.

Tightening torques:

– HECU mounting bolt – 8–10 Nm;

– brake pipe fastening nut – 13–17 Nm.

Wheel speed sensors

Removal

1. Remove the bolt securing the front wheel speed sensor and, after disconnecting the connector, remove the sensor ( rice. 7.7).

2. Remove the rear seat cushion.

3. Remove the rear pillar trim.

4. Remove the rear wheel.

5. Remove the bolt securing the rear wheel speed sensor and, after disconnecting the connector, remove the sensor ( rice. 7.8).

Examination

1. Connect an ohmmeter between the contacts of the wheel speed sensor and measure the resistance.

Nominal resistance:

– front wheel sensor – 1275–1495 Ohm;

– rear wheel sensor – 1275–1495 Ohm.

2. With a wheel speed sensor installed on the car, connect a voltmeter to the contacts of the sensor connector and, turning the wheel, measure the voltage.

A faulty ABS system does not disable the vehicle's braking system. But every driver who has driven a Hyundai Accent with the safety light on knows how much more difficult it becomes to drive the car in such conditions.

It is dangerous to delay repairing the abs block

The braking distance lengthens, the brake pedal becomes stiff, and it is not possible to quickly react to a neighbor’s maneuver. This is how emergency situations arise. Therefore, the Autopilot company recommends promptly repairing the Hyundai Accent ABS. The Moscow service center knows very well about all the “diseases” of this unit, characteristic of this model at 3-4 years of life. Most often, this is a blockage of the motor: there is a hole in the protective cylinder through which condensate is removed from the system, through which dirt, dust, and small crumbs enter the module. The problem is solved in different ways depending on the degree of “neglect” of the problem. Rebuilding the motor often helps - it will cost less. But it must be carried out by professionals: the elements of the module are located in a hard-to-reach place, therefore ABS repairs on Hyundai Accent must be carried out at special sites with the appropriate equipment at hand.

Prices are not high everywhere

The Autopilot service center has its own warehouse of parts - original and non-original for the driver’s choice. So you don’t have to worry about crazy costs, even if the entire unit has to be replaced due to corrosion and deposits. If desired, the client can be present in the repair area himself. These specialists are well versed in assembling Hyundai of all models and are always ready to show how it should be done correctly. In addition to replacing or restoring the ABS system, the Hyundai Autopilot center will perform any necessary operations for the car. It has everything required for high-quality, fast and professional diagnostics, prevention, regular and unscheduled maintenance of the “Russian Ten”.

Heading: Combination, transfer