B1386

B1371: Wheel speed FL, faulty or no signal
B1376: Wheel speed FR, faulty or no signal
B1381: Wheel speed RL, faulty or no signal
B1386: Wheel speed RR, faulty or no signal

Fault symptom
- TCS OFF lamp lit, Traction Control System (TCS) system not functioning.

Conditions
- Wheel speed signal incorrect or absent, or indicates a speed higher than 280 km1h

Important
- The diagnostic trouble code for wheel signals can be generated when the brakes are tested or if the car is started on a slippery uphill gradient, when the front wheels spin and the rear wheels remain stationary.
- If only one wheel spins and the other three remain stationary, the control module cannot tell whether the speed signals from the three stationary wheels are correct or false. In this case, trouble codes are generated for the three stationary wheels. The trouble codes are however automatically erased as soon as the signals return.
- If wheelspin continues for more than 20 seconds, while one of the wheels remains stationary, The TCS system is disconnected and the TCS OFF lamp lights. To restore the TCS function, the ignition must be switched off and back on again.

Action





1 If the ANTI LOCK lamp also lights while driving, obtain readings and act on diagnostic trouble codes in the Antilock Brake System (ABS) system, see Brakes.

- Ensure that there is no wheel speed signal:

2 Ignition in ON position.
- Connect the ISAT and select the "WHEEL SPEED" command in the "OBTAIN READOUTS" menu.
- Check by driving the car or by rotating each wheel that all four wheel speed signals are functioning.
- Note that the lowest display on the ISAT is 3km/h
- If all values are correct, proceed to point 4. If any value is incorrect, proceed to point 3.





3 Conduct continuity measurements on the lead for the wheel speed signal in question.
- Check between the Antilock Brake System (ABS) control module and the TCS control module for breaks, shorts and bypasses.
- If the values are correct, proceed to point 4.

Wheel: FL
Pin on ABS control module: 10
Pin on TCS control module: 25
Wheel: FR
Pin on ABS control module: 11
Pin on TCS control module: 7
Wheel: RL
Pin on ABS control module: 12
Pin on TCS control module: 24
Wheel: RR
Pin on ABS control module: 9
Pin on TCS control module: 8

4 Erase the diagnostic trouble code, test-drive the car and see if the diagnostic trouble code is reregistered.
- If the trouble code is registered, proceed to Control Module, Procedure Prior To Replacement.
- If the diagnostic trouble code is not registered, the action taken was correct or the fault was of the intermittent type.