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Home >> Jeep >> 2010 >> Commander Limited, RWD >> Repair and Diagnosis >> Brakes >> Traction Control >> Anti-Lock Brake System - Electrical Diagnostics >> DTC Troubleshooting >> C121A-Steering Angle Sensor Not Initialized >> Diagnostic Test

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.
    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. With the scan tool, erase DTCs.
    5. Test drive the vehicle by turning the vehicle left or right in a curving manner at a velocity between 10 and 25 km/hr (6 and 15 m.p.h.) for 1 minute.
    6. With the scan tool, read and record DTCs.

      Does the scan tool display: C121A-STEERING ANGLE SENSOR NOT INITIALIZED?

      Yes 

      • Go to step  2

      No 

  2. CHECK THE TERMINALS/CONNECTORS/WIRING HARNESS FOR DAMAGE 
    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. Check the Clockspring (SAS) installation.
    2. Check all related wiring for bruised, chafed, pierced, or partially broken wires.
    3. Check all related connectors for broken, bent, pushed out, or corroded terminals.

      Were any problems found?

      Yes 

      No 

      • Go to step  3
  3. CHECK THE VOLTAGE ON THE (F941) FUSED IGNITION CIRCUIT 
    Fig 1: Checking Fused Ignition Circuit Voltage At Clockspring Connector
    GC0090012Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Clockspring C3 (SAS) harness connector.
    3. Turn the ignition on.
    4. Measure the voltage of the (F941) Fused Ignition circuit.

      Is the voltage above 10 volts?

      Yes 

      • Go to step  4

      No 

  4. CHECK THE RESISTANCE OF THE (Z907) GROUND CIRCUIT 
    Fig 2: Checking Clockspring Ground Circuit
    GC0090013Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Measure the resistance between the (Z907) Ground circuit and ground.

      Is the resistance below 5.0 Ohms?

      Yes 

      No