P1572

P1572-BRAKE PEDAL STUCK ON





For a complete wiring diagram refer to Diagrams/Electrical.


- 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.







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, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

2. STOP LAMP SWITCH OPERATION

Turn the ignition off.

Disconnect the Stop Lamp Switch harness connector.

Measure the resistance between the (Z910) Ground circuit terminal and the (B15) Brake Signal 1 terminal in the Stop Lamp Switch.

Apply and release the Stop Lamp Switch while monitoring the ohmmeter.

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 (F943) Fused Ignition Switch terminal and the (B16) Brake Signal 2 circuit terminal in the Stop Lamp Switch.

Apply and release the Stop Lamp Switch while monitoring the ohmmeter.

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. (B15) BRAKE SIGNAL 1 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 (B15) Brake Signal 1 circuit from the Stop Lamp Switch harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 5

No

- Repair the open in the (B15) Brake Signal 1 circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


5. (B16) BRAKE SIGNAL 2 CIRCUIT OPEN





Measure the resistance of the (B16) Brake Signal 2 circuit from the Stop Lamp Switch harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 6

No

- Repair the open in the (B16) Brake Signal 2 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.

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.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test