Diagnostic Test

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

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. Road test the vehicle over 30 km/h (19 mph) for at least 30 seconds.
6. With the scan tool, read and record DTCs.
  Does the scan tool display: C121A-STEERING ANGLE SENSOR NOT INITIALIZED?
  
  Yes
  - Go To 2
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to STANDARD PROCEDURE .
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 Steering Angle Sensor installation is crucial for proper operation.
1. Check the Clockspring/Steering Angle Sensor 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
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
CHECK THE (F943) FUSED B(+) CIRCUIT FOR AN OPEN OR HIGH RESISTANCE

Fig 1: Checking Fused B(+) Circuit For An Open Or High Resistance
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the Clockspring C3 harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (F943) Fused B(+) circuit at the Clockspring C3 harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (F943) Fused B(+) circuit for an open.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (Z910) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE

Fig 2: Checking Ground Circuit For An Open Or High Resistance
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. With a 12-volt test light connected to B+, check the (Z910) Ground circuit at the Clockspring C3 harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Replace the Clockspring in accordance with the Service Information.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Repair the (Z910) Ground circuit for an open.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .