For 1990-2009 cars

### 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 B2705 02: Gearshift Unlock Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Shift Lock Control | B2705 02 | 1 | 2 | --
Shift Lock Ground | -- | 1 | -- | --
1. Shift lever will not move from PARK with the brake pedal pressed. 2. Shift lever will move from PARK without pressing on the brake pedal.

### 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 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 B2705 will clear when the malfunction is no longer present and the ignition switch is cycled.

• | A history DTC will clear after 100 ignition cycles with no current DTC active during the 100 ignition cycles.

### 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

### Circuit/System Verification

1. Ignition ON, observe the scan tool BCM Brake Status parameter while pressing and releasing the brake pedal. The parameter should change from ON to OFF when the brake pedal is depressed.

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

2. Ignition ON, while pressing the brake pedal, move the shift lever out of the PARK position. The shift lever should move 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 10 ohms between the ground circuit terminal 3 and ground.

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

3. Connect a test lamp between the ground circuit terminal 3 and the control circuit terminal 2.
4. Ignition ON, command the BCM BTSI - Park Lock Test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | 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 all circuits test normal, test or replace the shift lock actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Automatic Transmission Shift Lock Control Actuator Replacement

• | Control Module References for scan tool information