Antilock Braking System (ABS)

DTC 43: VES Steering Wheel Speed Sensor Circuit Fault (Part 1 Of 3):

DTC 43: VES Steering Wheel Speed Sensor Circuit Fault (Part 2 Of 3):

DTC 43: VES Steering Wheel Speed Sensor Circuit Fault (Part 3 Of 3):

DTC 43 VES Steering Wheel Speed Sensor Circuit Malfunction (For ABS With VES Only):

CIRCUIT DESCRIPTION
A 5 volt reference is supplied to the steering wheel speed sensor through Electronic Brake Control Module (EBCM) terminal "12" to sensor terminal "A". Steering wheel position input to the EBCM is provided through steering wheel speed sensor terminal "B" to EBCM terminal "23". Steering wheel speed sensor ground is provided through EBCM terminal "16".

DTC WILL SET WHEN
DTC 43 can be set anytime. A malfunction exists if the steering wheel speed sensor voltage is: less than 0.4 volt, greater than 4.67 volts or changes by more than 2 volts in 8 msec.

ACTION TAKEN
A malfunction DTC is stored, Variable Effort Steering (VES) is disabled and power steering returns to full assist.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks steering wheel speed sensor input to the EBCM.
2. Checks for a short between the steering wheel sensor input and ground circuits.
3. Checks for a short between the steering wheel sensor Viscous Converter Clutch (VCC) and ground circuits.
4. Checks for a short to ground in the steering wheel sensor input circuit.
5. Checks for a short to ground in the steering wheel sensor VCC circuit.
6. Checks for high resistance in the steering wheel sensor VCC circuit.
7. Checks for high resistance in the steering wheel sensor input circuit.
8. Checks for poor terminal contact.
9. Checks for proper voltage output of the EBCM.
10. Ensures malfunction was not due to physical damage of the steering wheel speed sensor circuits.
11. Checks for proper voltage with the steering wheel speed sensor disconnected.
12. Checks for high resistance in the steering wheel sensor ground.
13. Isolates high resistance to the EBCM or the ground circuit.
14. Ensures open ground was not due to a short to battery.
15. Ensures malfunction was not due to circuit damage or poor terminal contact.
16. Checks for a short to B+ in the steering wheel sensor input circuit.
17. Ensures malfunction was not due to physical damage of the circuitry.
18. Checks for proper voltage with the steering wheel speed sensor connected.
19. Checks for proper voltage with the steering wheel speed sensor disconnected.
20. Checks for a short to voltage in the steering wheel sensor VCC circuit.
21. Ensures malfunction was not due to physical damage of the circuitry.
22. Checks for a short between the steering wheel sensor VCC and input circuits.
23. Checks for proper resistance of the steering wheel speed sensor.
24. Ensures malfunction was not due to physical damage of the circuits.
25. Checks for an open resistor in the steering wheel speed sensor.

DIAGNOSTIC AIDS
An "Intermittent" malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Any circuitry, that is suspected as causing the intermittent malfunction, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.