GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0807: Clutch Pedal Position (CPP) Sensor Circuit Low Voltage

DTC P0808: Clutch Pedal Position (CPP) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

CPP Sensor Signal

P0807

P0807

P0808

P0806

CPP Sensor 5-Volt Reference

P0651, P0807

P0807

P0651, P0808

--

CPP Sensor Low Reference

--

P0808

P0808

--

Typical Scan Tool Information

CPP Sensor Voltage

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON.

CPP Sensor Voltage Parameter Normal Range: 0-volts with clutch pedal applied to 5-volts when clutch pedal is released.

CPP Sensor 5-Volt Reference

0 volts

0 volts

5 volts

CPP Sensor Signal

0 volts

0 volts

5 volts

CPP Sensor Low Reference

--

5 volts

--


CPP Sensor Percentage

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON.

CPP Sensor Percentage Parameter Normal Range: 0% with clutch pedal released to 100% when clutch pedal is applied.

CPP Sensor 5-Volt Reference

100%

100%

0-100%

CPP Sensor Signal

100%

100%

100%

CPP Sensor Low Reference

--

0%

--

Circuit/System Description

The clutch pedal position (CPP) is a three wire sensor, connected to a 5-volt reference circuit, a low reference circuit, and a signal circuit. The engine control module (ECM) supplies 5 volts to the CPP sensor, and also provides a sensor ground path on the low reference circuit. The CPP sensor sends a voltage signal to the ECM on the signal circuit. The voltage on the signal circuit will vary from a voltage less than or equal to 5 volts when the clutch pedal is released to a voltage less than or equal to 1.5 volts when the clutch pedal is applied.

Conditions for Running the DTC

P0807 and P0808

    • DTCs P0641 or P0651 are not set.
    • The system voltage is more than 9 volts.
    • The ignition is in the RUN position.

Conditions for Setting the DTC

P0807

The CPP sensor voltage is less than 0.1 volt for more than 1 second.

P0808

The CPP sensor voltage is more than 5.2 volts for more than 1 second.

Action Taken When the DTC Sets

P0807 and P0808 are Type A DTCs.

Conditions for Clearing the MIL/DTC

P0807 and P0808 are Type A DTCs.

Reference Information

Schematic Reference

Manual Transmission Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. If DTC P0641 or P0651 is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  2. Ignition ON, observe the scan tool CPP sensor percent parameter. The percentage should vary from 0 percent when the clutch pedal is released, to 100 percent when the clutch pedal is in the apply position.
  3. Perform the CPP learn procedure. Refer to Clutch Pedal Position Sensor Learn.
  4. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector of the CPP sensor.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal A and the negative post of the battery.
  3. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Ignition ON, verify that the scan tool CPP sensor parameter is less than 0.1 volts.
  7. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify that the scan tool CPP sensor parameter is between 4.8-5.2 volts.
  9. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, test or replace the CPP sensor.

Component Testing

  1. Ignition OFF, disconnect the harness connector of the CPP sensor.
  2. Measure the resistance between the signal terminal B and the low reference terminal A of the CPP sensor. Sweep the CPP sensor through the entire range. The resistance should vary low to high and high to low without any spikes or dropouts.
  3. If the resistance is erratic with spikes or dropouts, replace the CPP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Clutch Pedal Replacement
    •  Control Module References for ECM replacement, setup and programming