P0573

P0573-BRAKE SWITCH #1 CIRCUIT HIGH





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
Ignition on.

- Set Condition:
When the PCM recognizes Brake Switch is stuck in the high/off position. One Trip Fault. Three good trips to turn off the MIL.





Diagnostic Test

1. ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.Intermittent Condition
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. BRAKE LAMP SWITCH OPERATION
Turn the ignition off.
Disconnect the Brake Lamp Switch harness connector.
Measure the resistance between the (Z902) Ground circuit terminal and the (B15) Brake Switch Signal circuit terminal in the Brake Lamp Switch.
Apply and release the brake pedal while monitoring the ohmmeter.
Does the resistance change from below 5.0 ohms to an open circuit?

Yes

- Go To3

No

- Replace the Brake Lamp Switch.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. (B15) BRAKE SWITCH SIGNAL CIRCUIT OPEN




Disconnect the PCM harness connectors.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (B15) Brake Switch Signal circuit from the Brake Lamp Switch harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go To4

No

- Repair the open in the (B15) Brake Switch Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. GROUND CIRCUIT OPEN




Measure the resistance between the (Z902) Ground circuit and ground at the Brake Lamp Switch harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go To5

No

- Repair the open in the (Z902) Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
If there are no possible causes remaining, view repair.

Repair

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test