Diagnostic Test

WARNING: This page is about a different car, the 2012 RAM Cab & Chassis. 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. 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 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
  - Replace the ECU in accordance with the Service Information.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Test complete