GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The clutch switch is a normally closed switch. The powertrain control module (PCM) receives an ignition voltage on the clutch switch circuit when the clutch switch is closed. The PCM receives 0 voltage on the clutch switch circuit when the clutch switch is open.

This DTC determines if the transmission clutch switch has failed by monitoring for a clutch switch transition within a range from 0-38 km/h (0-24 mph).

Conditions for Running the DTC

No active vehicle speed sensor (VSS) DTCs

Conditions for Setting the DTC

    • Vehicle speed goes from 0 to more than 38 km/h (24 mph) and back to 0 km/h (0 mph) for 2 seconds without the PCM detecting a clutch transition.
    • This occurs 7 times before the diagnostic reports a fault.

Action Taken When the DTC Sets

    • The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the DTC

    • A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
    • A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Use a scan tool in order to clear the DTC.

Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

The following may cause an intermittent:

    • Poor connections--Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • Corrosion
    •  An improperly routed harness
    • Rubbed through wire insulation
    • Broken wire inside the insulation

The vehicle may need to be driven to locate an intermittent condition. Monitor the clutch switch parameter on the scan tool. If the parameter changes state while driving, inspect for proper connections.

Using Freeze Frame and Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass or a fail. Operate the vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature etc., that you observed. This will isolate when the DTC failed. For an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step determines if the fault is present.

Step

Action

Yes

No

1

Did you perform A Diagnostic System Check - Cruise Control?

Go to Step 2

Go to Diagnostic System Check - Cruise Control

2

  1. Turn OFF the ignition.
  2. Disconnect the appropriate PCM harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the CPP switch signal circuit with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 4

3

  1. Press the clutch pedal.
  2. Observe the test lamp.

Does the test lamp illuminate?

Go to Step 6

Go to Step 9

4

  1. Turn OFF the ignition.
  2. Disconnect the CPP switch harness connector.
  3. Turn On the ignition, with the engine OFF.
  4. Probe the ignition positive voltage circuit of the clutch pedal position switch harness connector with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

Test the CPP switch signal circuit for a open or high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

6

Test the CPP signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

7

Repair the open, high resistance or short to ground in the CPP switch ignition positive voltage circuit . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

--

8

Inspect for poor connection at the harness connector of the CPP switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Inspect for poor connection at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

10

Replace the CPP switch. Refer to Clutch Pedal Engine Start Switch Replacement in Clutch.

Did you complete the replacement?

Go to Step 12

--

11

Important:  The PCM must be reprogrammed after replacement.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls-4.3 L, Powertrain Control Module Replacement in Engine Controls-4.8 L, 5.3 L, 6.0 L, Engine Control Module Replacement in Engine Controls-6.6 L, or Powertrain Control Module Replacement in Engine Controls-8.1 L.

Did you complete the replacement?

Go to Step 12

--

12

Operate the vehicle with in the condition for cruise control operation.

Does the DTC reset?

Go to Step 2

System OK