Diagnosis Procedure

WARNING: This page is about a different car, the 2016 Infiniti Q50. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

Never check between wheel sensor harness connector terminals.

CHECK TIRE

Check the tire air pressure, wear and size. Refer to TIRE AIR PRESSURE .

Is the inspection result normal?

YES

GO TO STEP 4 .

NO

Adjust air pressure or replace tire and GO TO STEP 2 .

CHECK DATA MONITOR (1)

With CONSULT
1. Erase self-diagnosis result for "ABS".
2. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
3. Set the vehicle to READY/Start the engine.
4. Select "ABS" and "DATA MONITOR", check "FR LH SENSOR", "FR RH SENSOR", "RR LH SENSOR" and "RR RH SENSOR".
  NOTE:
  Set the "DATA MONITOR" recording speed to "10 msec".
5. Read a value (wheel speed) of both normal wheel sensors and error-detecting wheel sensor.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
Note the difference at 50 km/h (31 MPH) between the wheel speed detected by the error detecting wheel sensor and the maximum/minimum wheel speed detected by the normal wheel sensors, is the difference within 5%, respectively?

YES

GO TO STEP 3 .

NO

GO TO STEP 4 .

PERFORM SELF-DIAGNOSIS (1)

With CONSULT
1. Stop the vehicle.
2. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
3. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
4. Repeat step 2 to 3 two or more times.
5. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

GO TO STEP 4 .

NO

INSPECTION END

CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) POWER SUPPLY AND GROUND CIRCUIT

Check the ABS actuator and electric unit (control unit) power supply and ground circuit. Refer to DIAGNOSIS PROCEDURE .

Is the inspection result normal?

YES

GO TO STEP 5 .

NO

Repair / replace harness, connector, fuse, or fusible link.

CHECK WHEEL SENSOR AND SENSOR ROTOR
1. Turn the ignition switch OFF.
2. Disconnect wheel sensor harness connector.
3. Remove dust and foreign matter clinging to the wheel sensor and sensor rotor with a vacuum dust collector through the wheel sensor mounting hole.
  CAUTION:
  Install wheel sensor with no backlash and float, and tighten the mounting bolt to the specified torque.
  - Front: Refer to EXPLODED VIEW WITH TORQUE SPECIFICATIONS .
  - Rear: Refer to EXPLODED VIEW WITH TORQUE SPECIFICATIONS .
GO TO STEP 6 .

CHECK WHEEL SENSOR

Check the wheel sensor for damage.

Is the inspection result normal?

YES

GO TO STEP 7 .

NO

GO TO STEP 8 .

CHECK WHEEL SENSOR OUTPUT SIGNAL
1. Disconnect ABS actuator and electric unit (control unit) harness connector.
2. Connect ABS active wheel sensor tester (SST: J-45741-A) to wheel sensor using appropriate adapter.
3. Turn the ABS active wheel sensor tester power switch ON.
  NOTE:
  The green POWER indicator should illuminate. If the POWER indicator does not illuminate, replace the battery in the ABS active wheel sensor tester before proceeding.
4. Spin the wheel of the vehicle by hand and observe the red SENSOR indicator on the ABS active wheel sensor tester. The red SENSOR indicator should flash ON and OFF to indicate an output signal.
  NOTE:
  If the red SENSOR indicator illuminates but does not flash, reverse the polarity of the tester leads and retest.
Does the ABS active wheel sensor tester detect a signal?

YES

GO TO STEP 11 .

NO

GO TO STEP 8 .

REPLACE WHEEL SENSOR (1)

With CONSULT
1. Replace the wheel sensor.
  - Front: Refer to REMOVAL AND INSTALLATION .
  - Rear: Refer to REMOVAL AND INSTALLATION .
2. Connect ABS actuator and electric unit (control unit) harness connector.
3. Erase self-diagnosis result for "ABS".
4. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
5. Set the vehicle to READY/Start the engine.
6. Select "ABS" and "DATA MONITOR", check "FR LH SENSOR", "FR RH SENSOR", "RR LH SENSOR" and "RR RH SENSOR".
  NOTE:
  Set the "DATA MONITOR" recording speed to "10 msec".
7. Read a value (wheel speed) of both normal wheel sensors and error-detecting wheel sensor.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
Note the difference at 50 km/h (31 MPH) between the wheel speed detected by the error detecting wheel sensor and the maximum/minimum wheel speed detected by the normal wheel sensors, is the difference within 5%, respectively?

YES

GO TO STEP 9 .

NO

GO TO STEP 19 .

PERFORM SELF-DIAGNOSIS (2)

With CONSULT
1. Stop the vehicle.
2. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
3. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
4. Repeat step 2 to 3 two or more times.
5. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

GO TO STEP 10 .

NO

INSPECTION END

CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Check the ABS actuator and electric unit (control unit) harness connector for disconnection or looseness.
3. Check the wheel sensor harness connector for disconnection or looseness.
Is the inspection result normal?

YES

GO TO STEP 12 .

NO

Repair / replace harness or connector, securely lock the connector, and GO TO STEP 11 .

CHECK DATA MONITOR (2)

With CONSULT
1. Erase self-diagnosis result for "ABS".
2. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
3. Set the vehicle to READY/Start the engine.
4. Select "ABS" and "DATA MONITOR", check "FR LH SENSOR", "FR RH SENSOR", "RR LH SENSOR" and "RR RH SENSOR".
  NOTE:
  Set the "DATA MONITOR" recording speed to "10 msec".
5. Read a value (wheel speed) of both normal wheel sensors and error-detecting wheel sensor.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
Note the difference at 50 km/h (31 MPH) between the wheel speed detected by the error detecting wheel sensor and the maximum/minimum wheel speed detected by the normal wheel sensors, is the difference within 5%, respectively?

YES

GO TO STEP 12 .

NO

GO TO STEP 13 .

PERFORM SELF-DIAGNOSIS (3)

With CONSULT
1. Stop the vehicle.
2. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
3. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
4. Repeat step 2 to 3 two or more times.
5. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

GO TO STEP 13 .

NO

INSPECTION END

CHECK TERMINAL
1. Turn the ignition switch OFF.
2. Disconnect ABS actuator and electric unit (control unit) harness connector and then check the ABS actuator and electric unit (control unit) pin terminals for damage or loose connection with harness connector.
3. Disconnect wheel sensor harness connector and check each wheel sensor pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?

YES

GO TO STEP 16 .

NO

Repair / replace harness, connector, or terminal, and GO TO STEP 14 .

CHECK DATA MONITOR (3)

With CONSULT
1. Connect ABS actuator and electric unit (control unit) harness connector.
2. Connect wheel sensor harness connector.
3. Erase self-diagnosis result for "ABS".
4. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
5. Set the vehicle to READY/Start the engine.
6. Select "ABS" and "DATA MONITOR", check "FR LH SENSOR", "FR RH SENSOR", "RR LH SENSOR" and "RR RH SENSOR".
  NOTE:
  Set the "DATA MONITOR" recording speed to "10 msec".
7. Read a value (wheel speed) of both normal wheel sensors and error-detecting wheel sensor.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
Note the difference at 50 km/h (31 MPH) between the wheel speed detected by the error detecting wheel sensor and the maximum/minimum wheel speed detected by the normal wheel sensors, is the difference within 5%, respectively?

YES

GO TO STEP 15 .

NO

GO TO STEP 16 .

PERFORM SELF-DIAGNOSIS (4)

With CONSULT
1. Stop the vehicle.
2. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
3. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
4. Repeat step 2 to 3 two or more times.
5. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

GO TO STEP 16 .

NO

INSPECTION END

CHECK WHEEL SENSOR HARNESS

Turn the ignition switch OFF.
Disconnect ABS actuator and electric unit (control unit) harness connector.
Disconnect wheel sensor harness connector.

Check the continuity between ABS actuator and electric unit (control unit) harness connector and wheel sensor harness connector. (Check continuity while turning steering wheel left and right, or while moving center harness in wheel housing.)

Measurement connector and terminal for power supply circuit

ABS actuator and electric unit (control unit)		Wheel sensor			Continuity
Connector	Terminal	Connector		Terminal	Continuity
E24	23	E48	(Front LH wheel)	2	Existed
	21	E54	(Front RH wheel)
	26	C6	(Rear LH wheel)
	11	C5	(Rear RH wheel)

Measurement connector and terminal for signal circuit

ABS actuator and electric unit (control unit)		Wheel sensor			Continuity
Connector	Terminal	Connector		Terminal	Continuity
E24	27	E48	(Front LH wheel)	1	Existed
	12	E54	(Front RH wheel)
	30	C6	(Rear LH wheel)
	15	C5	(Rear RH wheel)

Check the continuity between ABS actuator and electric unit (control unit) harness connector and the ground.

ABS actuator and electric unit (control unit)		-	Continuity
Connector	Terminal	-	Continuity
E24	23, 27	Ground	Not existed
	21, 12
	26, 30
	11, 15

Is the inspection result normal?

YES

GO TO STEP 17 .

Repair / replace harness or connector, and GO TO STEP 17 .

CHECK DATA MONITOR (4)

With CONSULT
1. Connect ABS actuator and electric unit (control unit) harness connector.
2. Connect wheel sensor harness connector.
3. Erase self-diagnosis result for "ABS".
4. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
5. Set the vehicle to READY/Start the engine.
6. Select "ABS" and "DATA MONITOR", check "FR LH SENSOR", "FR RH SENSOR", "RR LH SENSOR" and "RR RH SENSOR".
  NOTE:
  Set the "DATA MONITOR" recording speed to "10 msec".
7. Read a value (wheel speed) of both normal wheel sensors and error-detecting wheel sensor.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
Note the difference at 50 km/h (31 MPH) between the wheel speed detected by the error detecting wheel sensor and the maximum/minimum wheel speed detected by the normal wheel sensors, is the difference within 5%, respectively?

YES

GO TO STEP 18 .

NO

Replace the ABS actuator and electric unit (control unit). Refer to REMOVAL AND INSTALLATION .

PERFORM SELF-DIAGNOSIS (5)

With CONSULT
1. Stop the vehicle.
2. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
3. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
4. Repeat step 2 to 3 two or more times.
5. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

Replace the ABS actuator and electric unit (control unit). Refer to REMOVAL AND INSTALLATION .

NO

INSPECTION END

REPLACE SENSOR ROTOR

With CONSULT
1. Replace the sensor rotor.
  - Front: Refer to REMOVAL AND INSTALLATION .
  - Rear: Refer to REMOVAL AND INSTALLATION .
2. Erase self-diagnosis result for "ABS".
3. Turn the ignition switch OFF → ON → OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF or ON.
4. Set the vehicle to READY/Start the engine.
5. Drive the vehicle at approx. 50 km/h (31 MPH) or more for approx. 2 minutes.
  NOTE:
  Vehicle must be driven after repair or replacement to erase the previous DTCs.
6. Stop the vehicle.
7. Turn the ignition switch OFF.
  NOTE:
  Wait at least 10 seconds after turning ignition switch OFF.
8. Set the vehicle to READY/Start the engine.
  NOTE:
  Wait at least 10 seconds after set the vehicle to READY/start the engine.
9. Repeat step 7 to 8 two or more times.
10. Perform self-diagnosis for "ABS".
Is DTC "C1115" detected?

YES

Replace the ABS actuator and electric unit (control unit). Refer to REMOVAL AND INSTALLATION .

NO

INSPECTION END