Chevrolet Silverado / GMC Sierra. Service manual - part 2590

CPP Sensor Percentage

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

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

Circuit

Ground

Open

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

5 volts

CPP Sensor Signal

0 volts

5 volts

CPP Sensor Low Reference

5 volts

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%

0-100%

CPP Sensor Signal

100%

CPP Sensor Low Reference

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

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

PSD SIE TITLE Error: SIE linked to empty Cell ID 167881

Connector End View Reference

Component Connector End Views

Description and Operation

Manual Transmission 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 .

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

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.

If greater than the specified value, test the low reference circuit for an open/high
resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and

ground.

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.

4. Ignition ON, verify that the scan tool CPP sensor parameter is less than 0.1 volts.

If greater than the specified value, test the signal circuit for a short to voltage. If the
circuit tests normal, replace the ECM.

5. 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.

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.

6. 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.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

If the resistance is erratic with spikes or dropouts, replace the CPP sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Clutch Pedal Replacement

Control Module References for ECM replacement, setup and programming

DTC P080A

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 Descriptor

DTC P080A

Clutch Pedal Position (CPP) Not Learned

Circuit/System Description

Conditions for Running the DTC

Clutch pedal fully applied.

Conditions for Setting the DTC

Clutch pedal position not learned.

Action Taken When the DTC Sets

P080A is a Type B DTC.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

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