C121E

C121E-BRAKE PRESSURE SENSOR COMPARATIVE PERFORMANCE

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 C121E-BRAKE PRESSURE SENSOR COMPARATIVE PERFORMANCE

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: C121E-BRAKE PRESSURE SENSOR COMPARATIVE PERFORMANCE?

Yes

- Go To 2

No

- Refer to the ABS-INTERMITTENT CONDITION TEST. Component Tests and General Diagnostics

2. RECHECK FOR A DTC C121E-BRAKE PRESSURE SENSOR COMPARATIVE PERFORMANCE

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: C121E-BRAKE PRESSURE SENSOR COMPARATIVE PERFORMANCE?

Yes

- Go To 3
- Perform ABS VERIFICATION TEST. ABS Verification Test

No

- Test complete

3. 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 200 psi?

Yes

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

No

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