4000 - 4999: 4363

4363-BRAKE LAMP SWITCH CIRCUIT / BRAKE PRESSURE SENSOR CORRELATION

For a complete wiring diagram consult Diagrams/Electrical Electrical Diagrams


- When Monitored:

With the ignition on.

- Set Condition:

When the Anti-Lock Brake Module indicates that the Brake Pressure Sensor Signal is irrational.








Diagnostic Test


1. CHECK FOR A DTC 4363-BRAKE LAMP SWITCH CIRCUIT / BRAKE PRESSURE SENSOR CORRELATION



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.

Does the scan tool display: 4363-BRAKE LAMP SWITCH CIRCUIT / BRAKE PRESSURE SENSOR CORRELATION?

Yes

- Go To 2

No

- Perform the ABS INTERMITTENT CONDITION diagnostic procedure.



Diagnostic Test


2. CHECK BRAKE SWITCH SIGNAL



Turn the ignition on.

With the scan tool look at the Brake Switch Signal.

Apply the brakes on and off while checking for a Brake Switch Signal change. If excessive travel occurs before switch engages adjust brake switch before continuing.

Does the scan tool display: Brake Switch Signal on and off when applied?

Yes

- Go To 3

No

- Check for Brake Switch Signal for short to voltage and internal short in Brake Switch. Repair as necessary
- Perform ABS VERIFICATION TEST. Verification Tests



3. CHECK BRAKE PRESSURE SENSOR

Start the engine.

With the scan tool look at Pressure Sensor Signal and the Brake Switch Signal.

With the brakes not applied the Pressure Sensor should read ± 12 bar (174 psi).

Apply the brakes the Pressure Sensor should read above 12 bar (174 psi).

Did Brake Pressure Sensor increase above 12 bar (174 psi)?

Yes

- Replace the Integrated Control Unit.
- Perform ABS VERIFICATION TEST. Verification Tests

No

- Go To 4



4. CHECK FOR AIR IN BRAKE SYSTEM


NOTE: Before continuing the brake system must be bled to verify there is no air in the brake system.

Turn ignition off.

Bleed brake system.

Was there any air in the brake system?

Yes

- Repair as needed.
- Perform ABS VERIFICATION TEST. Verification Tests

No

- Replace the Integrated Control Unit.
- Perform ABS VERIFICATION TEST. Verification Tests