LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2007 >> Wrangler Rubicon, Standard >> Repair and Diagnosis (Single Page) >> Brakes >> Anti-Lock Brakes >> Anti-Lock Brake System - Electrical Diagnostics >> Brakes - Abs Electrical Diagnostics >> DTC Troubleshooting >> C121A-Steering Angle Sensor Not Initialized >> Diagnostic Test

Diagnostic Test

  1. 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 

    1. Go to  2).

    No 

    1. Refer to ABS INTERMITTENT CONDITION .
  2. 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 

    1. Repair as necessary.
    2. Perform ABS VERIFICATION TEST .

    No 

    1. Go to  3).
  3. 3) CHECK THE VOLTAGE ON THE (F943) FUSED B(+) CIRCUIT 
    Fig 1: Measuring Voltage Of Fused B(+) Circuit
    GC0043985Courtesy of CHRYSLER LLC

    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 

    1. Go to  4).

    No 

    1. Repair the (F943) Fused B(+) circuit for an open.
    2. Perform ABS VERIFICATION TEST .
  4. 4) CHECK THE RESISTANCE OF THE (Z385) GROUND CIRCUIT 
    Fig 2: Measuring Resistance Of Ground Circuit
    GC0043986Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Steering Control Module harness connector.

    Measure the resistance between the (Z385) Ground circuit and ground.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Replace the Steering Control Module in accordance with the Service Information.
    2. Perform ABS VERIFICATION TEST .

    No 

    1. Repair the (Z385) Ground circuit for an open.
    2. Perform ABS VERIFICATION TEST .