C121D

C121D-BRAKE PRESSURE SENSOR CIRCUIT

For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on.

- Set Condition:
When the Anti-Lock Brake Module indicates that the Brake Pressure Sensor Signal is out of range.





Diagnostic Test

1. CHECK FOR A DTC C121D-BRAKE PRESSURE SENSOR CIRCUIT
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.
Start the engine.
Depress and release the brake pedal.
With the scan tool, read and record DTCs.
Does the scan tool display: C121D-BRAKE PRESSURE SENSOR CIRCUIT?

Yes

- Go to 2

No

- Refer to the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test

2. HCU/ECU ISOLATION
Turn the ignition off.
Separate the ECU from the HCU.
With the scan tool, monitor brake pressure.
Does the scan tool display brake pressure above 218 bar (3162 psi)?

Yes

- Replace the HCU.
- Perform ABS VERIFICATION TEST. ABS Verification Test.

No

- Replace the ECU.
- Perform ABS VERIFICATION TEST. ABS Verification Test.