B2705

DTC B2705

Diagnostic Instructions

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

DTC Descriptors

DTC B2705 02
- Gearshift Unlock Circuit Short to Ground

DTC B2705 05
- Gearshift Unlock Circuit Short to Battery or Open

Diagnostic Fault Information





Scan Tool Parameter Data

* Scan Tool Output Controls
* Scan Tool Data List

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

The engine control module (ECM)/powertrain control module (PCM) detects a system voltage below 10 volts for 5 seconds.

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.
* The BCM stores DTC B2705 in memory.

Conditions for Clearing the DTC

* A current DTC B2705 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.

Diagnostic Aids

* if the automatic transmission shift lock control circuit is shorted to ground, the automatic transmission shift lock control solenoid will be inoperative. The vehicle will shift out of PARK without pressing the brake pedal.
* Perform the tests while wiggling the wires and connectors. This may often cause an intermittent malfunction to appear.

Circuit/System Verification

Clear the DTC and verify that the brake pedal has to be pressed so that the transmission can be shifted 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 of resistance between the ground circuit terminal 3 and ground.

^ If greater than the specified range, test the ground circuit for an open. If the circuit tests normal, replace the shift lock control solenoid.

3. Ignition ON and the engine OFF, command the Brake To Shift Control output control ON and OFF. The automatic transmission shift lock control solenoid should turn ON and OFF and allow the transmission to be shifted out of the PARK position.

^ If unable to shift out of PARK, test for an open or short to ground in the control circuit.

4. Ignition ON and the engine OFF, connect a test lamp between the shift lock control solenoid ground circuit at the connector of the shift lock control solenoid and battery positive voltage. With the brake pedal applied, the test lamp should illuminate.

^ If test lamp does not illuminate, replace the shift lock control solenoid.

Repair Instructions

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

Automatic Transmission Control Replacement.