C121D

C121D-BRAKE PRESSURE SENSOR CIRCUIT

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- 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.





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.

1. Turn the ignition on.
2. With the scan tool, read and record DTCs.
3. With the scan tool, read and record Freeze Frame information.
4. With the scan tool, erase DTCs.
5. Start the engine.
6. Slowly depress and release the brake pedal.
7. With the scan tool, read and record DTCs.

Does the scan tool display: C121D-BRAKE PRESSURE SENSOR CIRCUIT?

Yes

- Go To 2

No

- Perform ABS INTERMITTENT CONDITION diagnostic procedure, ABS Intermittent Condition Test.

2. HCU/ECU ISOLATION
1. Turn the ignition off.
2. Separate the ECU from the HCU.
3. 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.