GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 Grand Prix 🢒 DTC 🢒 DTC B2705

Circuit Description

The body control module (BCM) controls the automatic transmission shift lock control solenoid by providing battery voltage to the automatic transmission shift lock control solenoid. The BCM utilizes a smart driver to control the voltage supplied 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 depressed.
    • The transmission the PARK position.

Conditions for Setting the DTC

The BCM output driver detects an open or short in the output control circuit.

Action Taken When the DTC Sets

The BCM disables the output control until the next ignition 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.
    • 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 battery positive voltage, the automatic transmission shift lock control solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal.
    • Perform the tests while wiggling the wires and connectors. This may often cause an intermittent malfunction to appear. Refer to Testing for Intermittent Conditions and Poor Connections

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Listen for an audible click when the automatic transmission shift lock control solenoid operates. Command both the ON and OFF states. Repeat the commands as necessary.

    2.

  2. Tests for voltage at the ignition 1 voltage circuit of the automatic transmission shift lock control solenoid.

    3.

  3. Verifies that the BCM is providing a ground to the automatic transmission shift lock control solenoid.

    4.

  4. Tests if ground is constantly being applied to the automatic transmission shift lock control solenoid.

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views or Body Control System Connector End Views

1

Did you perform A Diagnostic System Check -- Automatic Transmission Shift Lock Control?

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission Shift Lock Control

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the brake to shift output control ON and OFF.

Does the automatic transmission shift lock control solenoid turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the automatic transmission shift lock control solenoid.
  3. Connect a test lamp between the shift lock solenoid control circuit at the connector of the automatic transmission shift lock solenoid and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, command the brake to shift output control ON and OFF serveral times.

Does the test lamp illuminate ON and OFF with each command?

Go to Step 5

Go to Step 4

4

Does the test lamp remain illuminated?

Go to Step 6

Go to Step 7

5

Test the automatic transmission shift lock control solenoid ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

6

Test the control circuit of the automatic transmission shift lock control solenoid for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

7

Test the control circuit of the automatic transmission shift lock control solenoid for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness connector of the automatic transmission shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

10

Replace the automatic transmission shift lock control solenoid. Refer Automatic Transmission Shift Lock Actuator Replacement .

Did you complete the replacement?

Go to Step 12

--

11

Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 12

--

12
  1. Use the scan tool in order to clear the DTCs .
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK