Transmission Diagnosis

DTC P0704





Circuit Description
The clutch switch is a normally closed switch, clutch pedal released. The Powertrain Control Module (PCM) detects an ignition voltage on the clutch switch circuit when the clutch switch is closed. The PCM detects O volts on the clutch switch circuit when the clutch switch is open, clutch pedal depressed.
This DTC determines if the transmission clutch switch has failed by looking for a clutch switch transition during a predetermined drive cycle.

Conditions for Running the DTC
No VSS DTCs.

Conditions for Setting the DTC
^ The vehicle speed goes from 0 km/h (0 mph) to greater than 39 km/h (24 mph) and back to 0 km/h (0 mph) for 2 seconds without the PCM detecting a clutch transition.
^ This must occur 7 times before the diagnostic reports a fault.

Action Taken When the DTC Sets
^ The 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 MIL/DTC
^ A last test failed, current DTC, clears when the diagnostic runs and does not fail.
^ A History DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.

Diagnostic Aids

Important:
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
^ For any test that requires probing the PCM or a component harness connector, use the J 35616-A GM terminal test kit. Using this kit prevents damage to the harness/component terminals.
^ For clutch switch adjustment refer to Clutch Pedal Position Switch Replacement.
^ For an intermittent, refer to Symptoms - Engine Controls.








Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the fault is present.