B2705

DTC B2705

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC B2705 02
- Gearshift Unlock Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) controls the automatic transmission shift lock control solenoid by providing a battery positive voltage to the solenoid. The BCM utilizes a smart driver to control the voltage supply circuit to the automatic transmission shift lock control solenoid. The smart driver monitors the voltage and current flow of the control circuit.

Conditions for Running the DTC

* The ignition switch is in the ON position.
* The brake pedal is pressed.
* The transmission is in the PARK position.

Conditions for Setting the DTC

Sets if there is a short to ground in the automatic transmission shift lock control solenoid control circuit.

Action Taken When the DTC Sets

The BCM will not attempt to enable the voltage supply circuit of the automatic transmission shift lock control solenoid until the next key cycle.

Conditions for Clearing the DTC

* A current DTC will clear when the malfunction is no longer present and the ignition switch is cycled.
* All BCM history codes will clear after 100 ignition cycles with no current codes active during the 100 ignition cycles.

Reference Information
Schematic Reference

Shift Lock Control Schematics Electrical Diagrams
Connector End View Reference

Component Connector End Views Connector Views
Description and Operation

Automatic Transmission Shift Lock Control Description and Operation Description and Operation
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, Clear the DTC. Observe the scan tool BCM Brake Applied Output Signal parameter. The parameter should change from ON to OFF when the brake pedal is depressed and released.

• If the parameter does not change, refer to Stop Lamps Malfunction Stop Lamps Malfunction.

2. Press the brake pedal, the vehicle operator should not be able to move the shifter lever out of the PARK position.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the shift lock control solenoid.
2. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal B and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Install a test lamp between the ground circuit terminal B and the control circuit terminal A.
4. Ignition ON, command the BCM scan tool 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 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.

5. If the circuit tests normal, test or replace the shift lock control solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Transmission Control Replacement Transmission Control Replacement
* Control Module References Control Module References for BCM replacement, setup, and programming