P1572

P1572-BRAKE PEDAL STUCK ON

P1572 - Brake Pedal Stuck On:

WHEN MONITORED
Ignition on. In plant mode only.

SET CONDITION
PCM recognizes the Brake Pedal could not electrically indicate the applied (On) position with both switch inputs. One trip fault.

POSSIBLE CAUSES
- (B29) Brake switch no.1 signal circuit open
- (V32) Brake switch no.2 signal circuit open
- Stop lamp switch
- PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. ACTIVE DTC

NOTE: Make sure the Stop Lamp Switch is adjusted properly before continuing.

Ignition on, engine not running.
With a scan tool, read DTCs.

Q: Is the DTC active at this time?

YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. STOP LAMP SWITCH OPERATION
Turn the ignition off.
Disconnect the Stop Lamp Switch harness connector.
Measure the resistance between the (Z429) Ground circuit terminal and the (B29) Brake Switch No.1 Signal terminal in the Stop Lamp Switch.
Apply and release the brake pedal while monitoring the ohmmeter.

Q: Does the resistance change from below 5.0 ohms to open circuit when pressing and releasing the brake pedal switch?

YES: Go To 3
NO: Replace the Stop Lamp Switch. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. STOP LAMP SWITCH OPERATION
Measure the resistance between the (V30) Fused Ignition Switch Output terminal and the (V32) Brake Switch No.2 Signal circuit terminal in the Stop Lamp Switch.
Apply and release the brake pedal while monitoring the ohmmeter.

Q: Does the resistance change from below 5.0 ohms to open circuit when pressing and releasing the Stop Lamp switch?

YES: Go To 4
NO: Replace the Stop Lamp Switch. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. (B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN





Disconnect the C3 PCM harness connector.

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 (B29) Brake Switch No.1 Signal circuit from the Stop Lamp Switch harness connector to the appropriate terminal of special tool #8815.

Q: Is the resistance below 5.0 ohms?

YES: Go To 5
NO: Repair the open in the (B29) Brake Switch No.1 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. (V32) BRAKE SWITCH NO.2 SIGNAL CIRCUIT OPEN





Measure the resistance of the (V32) Brake Switch No.2 Signal circuit from the Stop Lamp Switch harness connector to the C1 ECM harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Go To 6
NO: Repair the open in the (L50) Brake Lamp Switch Output circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. 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.

Q: Were there any problems found?

YES: Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace and program the Powertrain Control Module per Service Information. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test