Diagnostic Test

WARNING: This page is about a different car, the 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR A DTC C121D-BRAKE PRESSURE SENSOR CIRCUIT
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 DTC's.
3. With the scan tool, read and record Freeze Fame information.
4. With the scan tool, erase DTC's.
5. Start the engine.
6. Press and release the brake pedal.
7. With the scan tool, read ABS DTCs.
  Does the scan tool display: C121D-BRAKE PRESSURE SENSOR CIRCUIT?
  
  Yes
  - Go To 2.
  No
  - Perform the ABS-INTERMITTENT CONDITION diagnostic procedure. Refer to ABS INTERMITTENT CONDITION .
RECHECK FOR A DTC C121D-BRAKE PRESSURE SENSOR CIRCUIT
1. Turn the ignition on.
2. With the scan tool, read and record DTC's.
3. With the scan tool, read and record Freeze Frame information.
4. With the scan tool, erase DTC's.
5. Start the engine.
6. Depress and release the brake pedal.
7. With the scan tool, read and record DTC's.
  Does the scan tool display: C121D-BRAKE PRESSURE SENSOR CIRCUIT?
  
  Yes
  - Go to 3.
  No
  - Test complete
REPLACE THE HYDRAULIC CONTROL UNIT (HCU) AND TEST FOR DTCST
1. Replace the Hydraulic Control Unit (HCU) in accordance with the Service Information. (Refer to HYDRAULIC/MECHANICAL ).
2. With the scan tool, erase DTC's.
3. Start the engine.
4. Press and release the brake pedal.
5. With the scan tool, read ABS DTCs.
  Did DTC C121D-BRAKE PRESSURE SENSOR CIRCUIT return?
  
  Yes
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. (Refer to MODULE, ANTI-LOCK BRAKE SYSTEM ).
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Test complete