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 Descriptor

DTC P0803: Skip Shift Solenoid Control Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+ Circuit to Skip Shift Solenoid

P0803

P0803

--

--

Skip Shift Solenoid Control Circuit

P0803

P0803

P0803

--

Typical Scan Tool Data

Skip Shift Solenoid

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Engine Running.

Parameter Normal Range: ON or OFF.

Skip Shift Solenoid Command

OFF

OFF

OFF

Circuit/System Description

Ignition voltage is supplied directly to the skip shift solenoid. The engine control module (ECM) controls the skip shift solenoid by grounding the control circuit via an internal switch called a low side driver. The low side driver has a fault line which monitors the control circuit. When the ECM commands the skip shift solenoid ON, the voltage on the control circuit should be low, near 0 V. When the ECM commands the control circuit to the skip shift solenoid OFF, the voltage should be high, near battery voltage.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

    • The ECM detects that the commanded state of the driver and the actual state of the control circuit does not match.
    • The condition exists for 5 seconds.

Action Taken When the DTC Sets

P0803 is a Type B DTC.

Conditions for Clearing the MIL/DTC

P0803 is a Type B DTC.

Diagnostic Aids

The battery must be fully charged and pass a battery test. Refer to Battery Inspection/Test.

Reference Information

Schematic Reference

Manual Transmission Schematics

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

Engine Control Module Scan Tool Information

Circuit/System Verification

  1. Ignition ON, command the skip shift solenoid ON and OFF, with a scan tool, while observing the following skip shift circuit status parameters.
  2. • Skip shift solenoid control Ckt. Short Gnd Test Status
    • Skip shift solenoid control Ckt. Open Test Status
    • Skip shift solenoid control Ckt. Short Volts Test Status
    Each parameter should toggle between OK and Not Run or Not Run and OK.
  3. 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

    Note: You must perform the Circuit/System Verification first.

  1. Disconnect the skip shift solenoid harness connector.
  2. Ignition ON, verify that a test lamp illuminates between the voltage circuit terminal B and ground.
  3. If the test lamp does not illuminate, test the voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, replace the skip shift solenoid.
  4. Verify that a test lamp does not illuminate between the voltage circuit terminal B and the control circuit terminal A.
  5. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Remove the test lamp.
  7. Command the skip shift solenoid ON with a scan tool. Verify with a scan tool that the skip shift solenoid Ckt. Short Volts Test Status parameter is OK.
  8. If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  9. Install a 3 A fused jumper wire between the skip shift control circuit terminal A and the voltage circuit terminal B. Command the skip shift solenoid ON with a scan tool. Verify with a scan tool that the affected skip shift solenoid Ckt. Short Volts Test Status parameter is displaying Fault.
  10. If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  11. If all the circuits test normal, replace the skip shift assembly.

Repair Instructions

    •  Gear Select/Skip Shift Solenoid Replacement
    •  Engine Control Module Programming and Setup
    •  Engine Control Module Replacement or Engine Control Module Replacement

Repair Verification

  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 60 seconds.
  5. Engine running, command skip shift solenoid ON and OFF with a scan tool, while observing the skip shift circuit status parameters. The circuit status parameters should change from OK to Not Run or Not Run to OK.
  6. If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.