NGC

P0572-BRAKE SWITCH 1 STUCK ON





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
When vehicle speed cycles from 0 kph to 48 kph (30 mph) at least 10 times.

- Set Condition:
The PCM detects that the actual state of Brake Signal 1 or Brake Signal 2 does not match the desired state during monitoring.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. DTC IS ACTIVE
Turn the ignition on.
With the scan tool, monitor the Brake Signal 1 and Brake Signal 2 states while pressing and releasing the brake pedal several times.
Do the Brake Signal states change appropriately as the pedal is pressed and released?

Yes

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking For An Intermittent DTC

No

- Go to 2

2. STOP LAMP SWITCH
Turn the ignition off.
Remove the Stop Lamp Switch and disconnect the harness connector.
Measure the resistance between the (Z911) Ground circuit terminal and the (B15) Brake Signal 1 circuit terminal in the Stop Lamp Switch.
Measure the resistance between the (F941) Fused Run/Start Relay Output circuit terminal and the (B16) Brake Signal 2 circuit terminal in the Stop Lamp Switch.
Apply and release the stop lamp switch plunger while monitoring the ohmmeter.
Does the resistance change from below 5.0 ohms to an open circuit?

Yes

- Go to 3

No

- Verify that there is good pin to terminal contact in the Switch and Control Module connectors. Replace the Stop Lamp Switch if no problems were found in the connectors.
- Perform the PCM Verification Test. Powertrain Verification Test

3. (B15) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND




Measure the resistance between ground and the (B15) Brake Signal 1 circuit in the Stop Lamp Switch harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 4

No

- Repair the short to ground in the (B15) Brake Signal 1 circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

4. (B16) BRAKE SIGNAL 2 CIRCUIT OPEN




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 (B16) Brake Signal 2 circuit between the Stop Lamp Switch harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 5

No

- Repair the open in the (B16) Brake Signal 2 circuit.
- Perform the PCM Verification Test.Powertrain Verification Test

5. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Switch and Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. Powertrain Verification Test