GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Impala 🢒 DTC 🢒 DTC B2712

Circuit Description

The body control module (BCM) controls the automatic transmission (A/T) shift lock control solenoid ground circuit and monitors the voltage of the ground control circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2712 Gearshift Lock Circuit Low

Conditions for Running the DTC

The control ground circuit of the A/T shift lock control solenoid must be OFF.

Conditions for Setting the DTC
    • The BCM detects the controlled ground circuit voltage is approximately equal to ground in the OFF state.
    • The condition above must be present for more than 0.3 seconds.
    • This DTC will be set after 20 seconds due to possible false failures.

Action Taken When the DTC Sets

The BCM stores DTC B2712 in memory.

Conditions for Clearing the DTC
    • A current DTC B2712 will clear if the short to ground or open in the controlled ground circuit of the A/T shift lock control solenoid is no longer detected by the BCM.
    • A history DTC B2712 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • A scan tool may be used to clear the DTC.

Diagnostic Aids
    • If DTC B2712 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to ground or open in the controlled ground circuit of the A/T shift lock control solenoid
       - The A/T shift lock control solenoid coil is intermittently shorted to ground internally.
       - The BCM is intermittently shorted to ground internally.

Test Description

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

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

    2.

  2. Tests for voltage at the A/T shift lock control solenoid.

    3.

  3. Verifies that the BCM is providing ground to the A/T shift lock control solenoid.

    4.

  4. Tests if ground is constantly being applied to the A/T shift lock control solenoid.

    5.

  5. The BCM must be programmed for the vehicle regular production option (RPO) configuration.

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: Shift Lock Control Connector End Views or Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the automatic transmission shift lock control solenoid ON and OFF.

Does the automatic transmission (A/T) shift lock control solenoid turn ON and OFF with each command?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the A/T shift lock control solenoid.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the A/T shift lock control solenoid supply voltage circuit at the A/T shift lock control solenoid with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

4

  1. Connect a test lamp between the control circuit of the A/T shift lock control solenoid and the A/T shift lock control solenoid supply voltage circuit of the A/T shift lock control solenoid.
  2. With a scan tool, command the A/T shift lock control solenoid ON and OFF .

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

Go to Step 11

Go to Step 5

5

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 6

6

Test the control circuit of the A/T shift lock control solenoid for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 12

7

Test the control circuit of the A/T shift lock control solenoid for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 12

8
  1. Turn OFF the ignition.
  2. Connect a test lamp between the ignition 1 voltage circuit at the A/T shift lock control switch and a good ground.
  3. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 9

Go to Step 13

9

Test the A/T shift lock control solenoid supply voltage circuit 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 17

Go to Step 10

10
  1. Inspect for proper A/T shift lock control switch adjustment. Refer to Stop Lamp Switch Adjustment in Lighting Systems.
  2. Inspect for poor connections at the A/T shift lock control switch. 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 17

Go to Step 14

11

Inspect for poor connections at the A/T 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 17

Go to Step 15

12

Inspect for poor connections at the harness connector of the body control module (BCM). 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 17

Go to Step 16

13

Repair the ignition 1 voltage circuit of the A/T shift lock control switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

14

Replace the A/T shift lock control switch. Refer to Stop Lamp Switch Replacement in Lighting Systems.

Did you complete the replacement?

Go to Step 17

--

15

Replace the A/T shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement .

Did you complete the replacement?

Go to Step 17

--

16

Important: Perform the setup procedure for the BCM.

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 17

--

17
  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