Diagnostic Test

CHECK FOR A DTC C1231-DRIVE TEST: STEERING ANGLE SENSOR
NOTE: This DTC must be active for the results of this test to be valid.

NOTE: If any of the following DTCs are present they must be repaired before continuing DTC C1219-STEERING ANGLE SENSOR ERRATIC PERFORMANCE or DTC C121A-STEERING ANGLE SENSOR NOT INITIALIZED.
1. Turn the ignition on.
2. With the scan tool, read and record DTCs.
3. With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.
4. Perform ECU initialization with drive test. Perform the ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
5. NOTE: The drive test requires a 90° turn.
6. Start the engine.
7. With the scan tool, read and record DTCs.
  Does the scan tool display: C1231-DRIVE TEST: STEERING ANGLE SENSOR?
  
  Yes
  - Go to step 2
  No
  - Perform the ABS INTERMITTENT CONDITION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
VERIFY THAT THE STEERING ANGLE SENSOR IS ACTIVE ON THE BUS
1. With the scan tool, select ECU View.
2. Verify that the Steering Angle Sensor is active on the bus.
  Is the Steering Angle Sensor active on the bus?
  
  Yes
  - Go to step 3
  No
  - Refer to Non-DTC Diagnostics/Communication - Diagnosis and Testing and perform the No Response from SAS diagnostic procedure.
CHECK STEERING ANGLE
1. Turn steering wheel so wheels point in a straight ahead position.
2. With scan tool check steering angle.
  Is the Steering Angle reading within ±15 degrees?
  
  Yes
  - Go to step 4
  No
  - Go to step 5
CHECK STEERING ANGLE CHANGE
1. Turn steering wheel so wheels point in a straight ahead position.
2. With scan tool check steering angle.
3. Rotate steering wheel to the right and the degrees will decrease and rotating steering wheel to the left the degrees will increase.
  Did the steering angle change accordingly?
  
  Yes
  - Replace the Anti-Lock Brake Module in accordance with the Service Information.
  - Perform the ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
  No
  - Replace the Clockspring (SAS) in accordance with the Service Information and clear offsets by initializing ECU with wheels pointing straight ahead.
  - Perform the ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
CHECK STEERING ANGLE SENSOR INSTALLATION
WARNING: To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, 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 SRS. Failure to take the proper precautions could result in accidental airbag deployment.

NOTE: Proper Clockspring (SAS) installation is crucial for proper operation.
1. Turn the ignition off.
2. Verify that the Clockspring (SAS) is properly installed. Refer to Restraints/CLOCKSPRING - Installation .
  Is the Clockspring properly installed?
  
  Yes
  - Replace the Anti-Lock Brake Module in accordance with the Service Information.
  - Perform the ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
  No
  - Repair as necessary and clear offsets by initializing ECU with wheels pointing straight ahead.
  - Perform the ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .