C1372

C 1372
Wheel Sensor Front Left. No Signal

Fault symptoms
ABS warning lamp on. ABS not functioning.

Conditions
DTC is generated by open circuit.

Diagnostic help
^ FL wheel speed sensor signal can be read using diagnostic tool.
- Select "Read Values".
- Select" Wheel Speed Front Left".
The current wheel speed in km/h is displayed.
With the front of the car raised off the ground, the diagnostic tool should show a reading of about 5 km/h when the FL wheel is rotated by hand at a speed of about one turn a second.
^ For tracing electrical faults, the diagnostic tool can be used to take readings from the control module's wheel-sensor inputs.
- Select "Read Values"
- Select "Wheel-sensor output"
The reading is used to determine whether there is a break in the circuit between the control module and one of the wheel sensors. If the circuit is OK, the reading should be approximately 3.4 V.
If the circuit to the front left wheel is not OK, the value will be about 2.7 V.

Diagnostic procedure
1. Checking Control Module Input





Unplug the connector.

^ Wheel sensor, front left (298FL)
Go to step 2

2. Checking Control Module Input





Turn the ignition switch
To the ON position.
Go to step 3

3. Checking Control Module Input

Take a voltage reading.





^ Pin 1, wheel sensor, front left (298fl)





^ B- (ground)

The reading should be 4.7 V

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO
Go to step 7

YES
Go to step 4

4. Checking Wheel Sensor Grounding

Take a voltage reading.





^ B+ (batt pos.)





^ Pin 2- Wheel sensor front left (298fl)

The value should be B+ (batt. voltage).

Checking the wiring harness.
Jiggle the leads and in-fine connectors at several places and indifferent directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO
Go to step 5

YES
Go to step 6

5. Rectifying The Lead





Repair or replace the lead between pin 6 of the control module and pin 2 of the wheel sensor.

^ After repair is complete
Go to step 8

6. Changing Components





^ Change - Wheel sensor, front left

After repair is complete
Go to step 8

7. Rectifying The Lead





^ Repair or replace the lead between pin 7 of the control module and pin 1 of the wheel sensor.

^ After repair is complete
Go to step 8

8. Final Check





^ Clear the diagnostic trouble codes in all systems.





Carry out a drive cycle.-

^ Drive the car at varying engine loads and engine rpm for five minutes.
Evaluate the drive cycle:





^ Check that the diagnostic trouble code has not recurred

Is the function correct?

NO
Go to step

YES
go to step

9. Final Check

The steps taken to rectify the fault were correct.
Diagnosis is complete

10. Final Check

Diagnosis for this fault code is complete.
Refer to "Before Changing A Control Module" at General.