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.

Typical Scan Tool Data

Clutch Safety Switch

Display Parameters

Normal Range

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Ignition ON, clutch pedal released.

 

Clutch Pedal Safety Switch

Applied/Released

Applied

Released

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Circuit/System Description

The clutch safety switch is a normally open switch. When the ignition is ON, the engine control module (ECM) supplies B+ on the signal circuit to the clutch safety switch. A wire from the clutch safety switch to chassis ground completes the electrical circuit. The ECM senses B+ on the signal circuit with the clutch pedal released, and zero volts with the clutch pedal depressed.

Diagnostic Aids

This test procedure requires that the battery is completely charged. Refer to Battery Inspection/Test.

Reference Information

Schematic Reference

Manual Transmission Schematics

Connector End View Reference

Manual Transmission Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Scan Tool Data List

Scan Tool Output Controls

Scan Tool Data Definitions

Circuit/System Verification

  1. Start the engine, with the clutch pedal depressed. The engine should start and run.
  2. 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.

Circuit/System Testing

  1. Ignition OFF, disconnect the clutch safety switch harness connector.
  2. Test for less than 5 ohms between the clutch safety switch harness connector terminal B and the negative battery post.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, test for 11-13 V on the clutch safety switch harness connector terminal A and ground.
  5. If not within 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, replace the clutch safety switch.

Component Testing

  1. Ignition OFF, disconnect the clutch safety switch harness connector.
  2. Test for less than 5 ohms between terminals A and B on the clutch safety switch.
  3. If greater than the specified value, replace the clutch safety switch.

Repair Verifications

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Clutch Pedal Engine Start Switch Replacement