P1572

P1572-BRAKE PEDAL STUCK ON

Special Tools:










For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

Stop Lamp Switch - Description for further information.

- When Monitored:
Ignition on. In plant mode only.

- Set Condition:
The Powertrain Control Module (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. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

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

1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.
3. It may be necessary to press and release the Brake Pedal to get the fault to become Active.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. STOP LAMP SWITCH OPERATION
1. Turn the ignition off.
2. Disconnect the Stop Lamp Switch harness connector.
3. Measure the resistance between the (Z916) Ground circuit terminal and the (B15) Brake Switch No.1 Signal terminal in the Stop Lamp Switch.
4. 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. Stop Lamp Switch - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. STOP LAMP SWITCH OPERATION
1. Measure the resistance between the (F941) Fused Ignition Switch terminal and the (B16) Brake Switch No.2 Signal circuit terminal in the Stop Lamp Switch.
2. 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. Stop Lamp Switch - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. (B15) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN




1. 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 the PCM Pinout Box (8815A) to perform diagnosis.

2. Measure the resistance of the (B15) Brake Switch No.1 Signal circuit from the Stop Lamp Switch harness connector to the appropriate terminal of PCM Pinout Box.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the open in the (B15) Brake Switch No.1 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. (B16) BRAKE SWITCH NO.2 SIGNAL CIRCUIT OPEN




1. Measure the resistance of the (B16) Brake Switch No.2 Signal circuit from the Stop Lamp Switch harness connector to the appropriate terminal of PCM Pinout Box.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the open in the (B16) Brake Switch No.2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

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

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. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.