C1216

DTC C1201: Front right wheel speed sensor (abnormal output signal)

DTC C1206: Front left wheel speed sensor (abnormal output signal)

DTC C1211: Rear right wheel speed sensor (abnormal output signal)

DTC C1216: Rear left wheel speed sensor (abnormal output signal)

CAUTION:
^ If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Diagnose the CAN bus lines before the DTC.
^ Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

CIRCUIT OPERATION
^ A toothed wheel speed rotor generates a voltage pulse as it moves across the pickup field of each wheel speed sensor.
^ The amount of voltage generated at each wheel is determined by the clearance between the wheel speed rotor teeth and the wheel speed sensor, and by the speed of rotation.
^ Sends alternating current signals at frequencies which are proportional to the rotation speeds of each wheel to the ABS electronic control unit (ABS-ECU).
^ The ABS hydraulic unit modulates the amount of braking force individually applied to each wheel cylinder.

DTC SET CONDITIONS
The ABS-ECU monitors the signals from each wheel speed sensor while the vehicle is being driven. If any fault below is found in these sensor signals, the ECU will set the relevant diagnostic trouble code.
^ Missing sensor signal
^ Sensor signal, which will not be created under normal operation
^ Significant difference among the wheel speed sensor signals

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THESE DTCS ARE TO SET ARE:)

Current trouble
^ Malfunction of the wheel speed sensor or wheel speed rotor
^ Damaged wiring harness or connector
^ Malfunction of the hydraulic unit (integrated with ABS-ECU)

Past trouble
^ Carry out diagnosis with particular emphasis on connector(s) or wiring harness in wheel speed sensor circuit. For diagnosis procedures, refer to "How to cope with past trouble".

PAST TROUBLE
For diagnosis procedures, refer to "How to cope with past trouble".

DIAGNOSIS

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A
^ MB991970: ABS Check Harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the "ON" position.
3) Diagnose the CAN bus line.
4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?
YES: Go to Step 3
NO: Repair the CAN bus line. Then go to Step 2.

STEP 2. Recheck for diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Turn the ignition switch to the "ON" position.
2) Erase the DTC.
3) Turn the ignition switch to the "LOCK" (OFF) position.
4) Turn the ignition switch to the "ON" position.
5) Check if the DTC is set.
6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1201, C1206, C1211 or C1216 set?
YES: Go to Step 3
NO: The procedure is complete.

STEP 3. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958, Use scan tool MB991958 to check whether DTC codes C1200, C1205, C1210 and C1215 have been set simultaneously.

1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the "ON" position.
3) Check whether DTC C1200, C1205, C1210 or C1215 have been set.
4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1200, C1205, C1210 or C1215 set?
YES: Carry out diagnosis relevant to DTC C1200, C1205, C1210 or C1215.
NO: Go to Step 4.

STEP 4. Check the installation condition of the wheel speed sensors.
For the wheel speed sensor, which the DTC code indicates, check whether the sensor or its mounting bolts are loosened.
^ DTC C1201 is set: Front right wheel speed sensor
^ DTC C1206 is set: Front left wheel speed sensor
^ DTC C1211 is set: Rear right wheel speed sensor
^ DTC C1216 is set: Rear left wheel speed sensor

Q: Is the wheel speed sensor installed correctly?
YES: Go to Step 5.
NO: Reinstall the wheel speed sensor correctly. Then go to Step 16.

STEP 5. Check the wheel speed sensor after it is removed from the vehicle.
Check the wheel speed sensor which the DTC code indicates.
^ DTC C1201 is set: Front right wheel speed sensor
^ DTC C1206 is set: Front left wheel speed sensor
^ DTC C1211 is set: Rear right wheel speed sensor
^ DTC C1216 is set: Rear left wheel speed sensor

Q: Is the wheel speed sensor in good condition?
YES: Go to Step 6.
NO: Replace the wheel speed sensor. Then go to Step 16.

STEP 6. Check the wheel bearing for looseness.

NOTE: If the wheel bearing is loose, the gap between the wheel speed sensor and rotor may become excessive. Check the wheel bearing, which DTC code indicates, for looseness.

^ DTC C1201 is set: Check the front right wheel bearing.
^ DTC C1206 is set: Check the front left wheel bearing.
^ DTC C1211 is set: Check the rear right wheel bearing.
^ DTC C1216 is set: Check the rear left wheel bearing.

Q: Is the wheel bearing end play within the standard value?
YES: Go to Step 7.
NO (front bearing end play is not within the standard value): Replace the front hub assembly. NO (rear bearing end play is not within the standard value): Replace the rear hub assembly.

STEP 7. Check the wheel speed rotor.
Check the wheel speed rotor, which DTC code indicates, for foreign material or deformation.
^ DTC C1201 is set: Front right wheel speed sensor
^ DTC C1206 is set: Front left wheel speed sensor
^ DTC C1211 is set: Rear right wheel speed sensor
^ DTC C1216 is set: Rear left wheel speed sensor

Q: Is the wheel speed rotor in good condition?
YES: Go to Step 8.
NO (front bearing end play is not within the standard value): If the wheel speed rotor is contaminated with foreign material, clean it. If the driveshaft is deformed, replace it.
NO (rear bearing end play is not within the standard value): If the wheel speed rotor is contaminated with foreign material, clean it. If the wheel speed rotor is deformed, replace it.

STEP 8. Measure the voltage at ABS-ECU connector A-02.

1) Disconnect the connector A-02, and connect special tool ABS Check Harness (MB991970) to the wiring harness-side connector.

NOTE: Do not connect special tool ABS Check Harness (MB991970) to the ABS-ECU.

2) Turn the ignition switch to the "ON" position.
3) Measure the voltage between the relevant signal and ground terminals in the wheel speed sensor circuit and body ground. It should be less than 1V.
^ DTC C1201 is set: Between signal terminal 9 and body ground, and between ground terminal 10 and body ground
^ DTC C1206 is set: Between signal terminal 26 and body ground, and between ground terminal 16 and body ground
^ DTC C1211 is set: Between signal terminal 11 and body ground, and between ground terminal 17 and body ground
^ DTC C1216 is set: Between signal terminal 28 and body ground, and between ground terminal 27 and body ground

Q: Does the voltage measure 1 V or less?
YES: Go to Step 9.
NO (When the voltage between terminal 9 or 10 - and body ground measures more than 1 V): Go to Step 11.
NO (When the voltage between terminal 26 or 16 - and body ground measures more than 1 V): Go to Step 12.
NO (When the voltage between terminal 11 or 17 - and body ground measures more than 1 V): Go to Step 13.
NO (When the voltage between terminal 28 or 27 - and body ground measures more than 1 V): Go to Step 14.

STEP 9. Measure the resistance at ABS-ECU connector A-02.

1) Disconnect the connector A-02, and connect special tool ABS Check Harness (MB991970) to the wiring harness-side connector. NOTE: Do not connect special tool ABS Check Harness (MB991970) to the ABS-ECU.
2) Measure the resistance between the relevant signal and ground terminals in the wheel speed sensor circuit and body ground. OK if there is no continuity.
^ DTC C1201 is set: Between signal terminal 9 and body ground, and between ground terminal 10 and body ground
^ DTC C1206 is set: Between signal terminal 26 and body ground, and between ground terminal 16 and body ground
^ DTC C1211 is set: Between signal terminal 11 and body ground, and between ground terminal 17 and body ground
^ DTC C1216 is set: Between signal terminal 28 and body ground, and between ground terminal 27 and body ground

Q: Does continuity exist?
YES (Continuity exists between terminal 9 or terminal 10 and body ground): Go to Step 11.
YES (Continuity exists between terminal 26 or terminal 16 and body ground): Go to Step 12.
YES (Continuity exists between terminal 11 or terminal 17 and body ground): Go to Step 13.
YES (Continuity exists between terminal 28 or terminal 27 and body ground): Go to Step 14.
NO: Go to Step 10.

STEP 10. Measure the resistance at ABS-ECU connector A-02.

1) Disconnect the connector A-02, and connect special tool ABS Check Harness (MB991970) to the wiring harness-side connector.

NOTE: Do not connect special tool ABS Check Harness (MB991970) to the ABS-ECU.

2) Measure the resistance between the relevant signal and ground terminals in the wheel speed sensor circuit.
^ DTC C1201 is set: Between signal terminal 9 and ground terminal 10
^ DTC C1206 is set: Between signal terminal 26 and ground terminal 16
^ DTC C1211 is set: Between signal terminal 11 and ground terminal 17
^ DTC C1216 is set: Between signal terminal 28 and ground terminal 27
Standard Value: 1.24 - 1.64 kOhms

Q: Is the resistance between terminals 16 and 26, 9 and 10, 27 and 28, or 11 and 17 within the standard value?
YES (When resistances between all terminals are within the standard value): Go to Step 15.
NO (When resistance between terminals 9 and 10 is not within the standard value): Go to Step 11.
NO (When resistance between terminals 16 and 26 is not within the standard value): Go to Step 12. NO (When resistance between terminals 11 and 17 is not within the standard value): Go to Step 13.
NO (When resistance between terminals 27 and 28 is not within the standard value): Go to Step 14.

STEP 11. Check ABS-ECU connector A-02 and wheel speed sensor [front: RH] connector A-01 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are ABS-ECU connector A-02 and wheel speed sensor [front: RH] connector A-01 damaged?
YES: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Then go to Step 16.
NO: Open or short circuit may be present in the front right wheel speed sensor circuit. Repair the wiring harness between ABS-ECU connector A-02 (terminals 9 and 10) and front right wheel speed sensor A-01 (terminals 2 and 1).Then go to Step 16.

STEP 12. Check ABS-ECU connector A-02 and wheel speed sensor [front: LH] connector A-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are ABS-ECU connector A-02 and wheel speed sensor [front: LH] connector A-04 damaged?
YES: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Then go to Step 16.
NO: Open or short circuit may be present in the front right wheel speed sensor circuit. Repair the wiring harness between ABS-ECU connector A-02 (terminals 16 and 26) and front left wheel speed sensor A-04 (terminals 1 and 2).Then go to Step 16.

STEP 13. Check ABS-ECU connector A-02, intermediate connector C-25 and wheel speed sensor [Rear: RH] connector F04 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are ABS-ECU connector A-02, intermediate connector C-25 and wheel speed sensor [Rear: RH] connector F-04 damaged?
YES: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Then go to Step 16.
NO: Open or short circuit may be present in the rear right wheel speed sensor circuit. Repair the wiring harness between ABS-ECU connector A-02 (terminals 11 and 17) and rear right wheel speed sensor F-04 (terminals 1 and 2).Then go to Step 16.

STEP 14. Check ABS-ECU connector A-02, intermediate connector C-25 and wheel speed sensor [rear: LH] connector F-07 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are ABS-ECU connector A-02, intermediate connector C-25 and wheel speed sensor [rear: LH] connector F-07 damaged?
YES: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Then go to Step 16.
NO: Open or short circuit may be present in the rear left wheel speed sensor circuit. Repair the wiring harness between ABS-ECU connector A-02 (terminals 27 and 28) and rear left wheel speed sensor F07 (terminals 2 and 1).Then go to Step 16.

STEP 15. Recheck for diagnostic trouble code.

Check again if the DTC is set.
1) Turn the ignition switch to the "ON" position.
2) Erase the DTC
3) Turn the ignition switch to the "LOCK" (OFF) position.
4) Turn the ignition switch to the "ON" position.
5) Check if the DTC is set.
6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1201, C1206, C1211 or C1216 set?
YES: Replace the hydraulic unit (integrated with ABS-ECU). Then go to Step 16.
NO: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.

STEP 16. Recheck for diagnostic trouble code.