Operation CHARM: Car repair manuals for everyone.

C121A







C121A-STEERING ANGLE SENSOR NOT INITIALIZED





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
Continuous monitoring.

- Set Condition:
When the Anti-Lock Brake Module detects a low voltage at the Steering Angle Sensor or Steering Angle Sensor failure.





Diagnostic Test

1. CHECK FOR A DTC C121A-STEERING ANGLE SENSOR NOT INITIALIZED
NOTE: This DTC must be active for the results of this test to be valid.

Turn the ignition on.
With the scan tool, read and record DTCs.
With the scan tool, read and record Freeze Frame information.
With the scan tool, erase DTCs.
Road test the vehicle over 30 km/h (19 mph) for at least 30 seconds.
With the scan tool, read and record DTCs.
Does the scan tool display: C121A-STEERING ANGLE SENSOR NOT INITIALIZED?

Yes

- Go to 2

No

- Refer to the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test

2. CHECK THE TERMINALS/CONNECTORS/WIRING HARNESS FOR DAMAGE
WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, occupant classification system, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the supplemental restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

NOTE: Proper Steering Angle Sensor installation is crucial for proper operation.

Check the Steering Angle Sensor installation.
Check all related wiring for bruised, chafed, pierced, or partially broken wires.
Check all related connectors for broken, bent, pushed out, or corroded terminals.
Were any problems found?

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Go to 3

3. CHECK THE VOLTAGE ON THE (F943) FUSED B(+) CIRCUIT




Turn the ignition off.
Disconnect the Steering Control Module harness connector.
Turn the ignition on.
Measure the voltage of the (F943) Fused B(+) circuit.
Is the voltage above 10 volts?

Yes

- Go to 4

No

- Repair the (F943) Fused B(+) circuit for an open.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

4. CHECK THE RESISTANCE OF THE (Z910) GROUND CIRCUIT




Turn the ignition off.
Disconnect the Steering Control Module harness connector.
Measure the resistance between the (Z910) Ground circuit and ground.
Is the resistance below 5.0 ohms?

Yes

- Replace the Steering Control Module.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Repair the (Z910) Ground circuit for an open.
- Perform ABS VERIFICATION TEST. ABS Verification Test.