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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Shift Lock Control Solenoid Control | B2705 02 | B2705 04 | 2 | -- |
Shift Lock Control Solenoid Ground | -- | 1 | -- | -- |
1. Unable to move shift lever with brake level depressed. 2. Shift lever moves without brake pedal depressed. | ||||
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
Connector End View Reference
Description and Operation
Automatic Transmission Shift Lock Control Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, clear the DTC. Observe the scan tool BCM Brake Applied Output Signal parameter while pressing and releasing the brake pedal. The parameter should change between ON and OFF.
| ⇒ | If the parameter does not change between the specified values, refer to Stop Lamps Malfunction . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the shift lock control solenoid.
- Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal A and ground.
- Install a test lamp between the ground circuit terminal A and the control circuit terminal B.
- Ignition ON, command the scan tool BCM Brake To Shift Control output control ON and OFF. The test lamp should turn ON and OFF as commanded.
- If the circuit tests normal, replace the transmission control.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Component Testing
- Install a 10A fused jumper wire between the control circuit terminal 3 and 12 volts. Install a jumper wire between the ground circuit terminal 9 and ground.
- Listen for the solenoid to turn ON and OFF.
| ⇒ | If the function does not perform as specified, replace the transmission control. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Transmission Control Replacement for the 6T70/6T75 transmission |
| • | Transmission Control Replacement for the 4T45-E transmission |
| • | Control Module References for BCM replacement, setup and programming |
