Transmission Control Lever Malfunction
Transmission Control Lever MalfunctionDiagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure.
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) controls the shift lock solenoid by providing battery voltage to the shift lock control solenoid. The BCM utilizes a smart driver to control the voltage supplied to the shift lock solenoid. The smart driver monitors the voltage and current flow of the control circuit.
Diagnostic Aids
^ Use a scan tool to verify there are no brake pedal position sensor and/or transmission internal mode switch (IMS) DTCs set that could cause the BCM not to provide battery voltage to the A/T shift lock solenoid.
^ If the automatic transmission shift lock control circuit is shorted to battery positive voltage, the A/T shift lock solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal, with Floor Shift. On vehicles with Column Shift the shifter will be locked in PARK.
Reference Information
Schematic Reference
[Shift Lock Control Schematics]
Connector End View Reference
[Component Connector End Views]
Description and Operation
[Automatic Transmission Shift Lock Control Description and Operation]
Electrical Information Reference
^ [Circuit Testing]
^ [Connector Repairs]
^ [Testing for Intermittent Conditions and Poor Connections]
^ [Wiring Repairs]
Scan Tool Reference
[Control Module References] for scan tool information Programming and Relearning
Circuit/System Verification
1. Ignition ON, while pressing the brake pedal, observe the scan tool Brake Applied Output Signal parameter. The reading should be ON with the brake pedal pressed.
2. Ignition ON, observe the scan tool BCM Shift Lock Solenoid Command parameter. The parameter should change from ON to OFF when the brake pedal is depressed.
> If not the specified parameter, replace the BCM.
3. Press the brake pedal, the vehicle operator should be able to move the shifter lever out of the park position.
Circuit/System Testing
1. Ignition ON, while pressing the brake pedal, observe the scan tool Brake Applied Output Signal parameter. The reading should be ON with the brake pedal pressed.
2. Ignition OFF, disconnect the harness connector at the automatic transmission shift lock actuator.
3. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal 3 and ground.
> If greater than the specified range, test the ground circuit for an open/high resistance.
4. Connect a test lamp between the control circuit terminal 1 and ground.
5. Ignition ON, command the scan tool BCM Shift Lock Solenoid output control ON and OFF. The test lamp should turn ON and OFF as commanded.
> If the test lamp is always ON, test the control circuit for a short to voltage. If all circuits test normal, test or replace the BCM.
> If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If all circuits test normal, test or replace the BCM.
6. If all circuits test normal, test or replace the transmission control.
Component Testing
1. Install a 10A fused jumper wire between the control circuit terminal 1 and 12 volts. Install a jumper wire between the ground circuit terminal 3 and ground.
2. Listen for the solenoid to turn ON and OFF.
> If the function does not perform as specified, replace the shift control.
Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure.
^ [Transmission Control Replacement]
^ [Control Module References] for BCM replacement, setup and programming Programming and Relearning