GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Colorado Pickup - 4WD 🢒 Transmission/Transaxle 🢒 Shift Lock Control 🢒 DTC B2707

Circuit Description

The body control module (BCM) controls the automatic transmission shift lock control solenoid by providing controlled battery voltage to the automatic transmission shift lock control solenoid. The BCM utilizes a smart driver to monitor the voltage and current flow of the automatic transmission shift lock control solenoid control circuit. DTC B2707 will set when the BCM detects a short to ground or open circuit when the solenoid is in the ON state.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2707 Gearshift Unlock Circuit Low

Conditions for Running the DTC
    • The ignition switch is in the ON position.
    • The brake pedal is released.
    • The transmission is in the PARK position.

Conditions for Setting the DTC

The BCM detects the control circuit of the shift lock control solenoid is grounded or opened for a minimum of 1 second.

Action Taken When the DTC Sets

The BCM disables shift lock control solenoid operation until the next key cycle.

Conditions for Clearing the DTC
    • A current DTC B2707 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 control circuit of the automatic transmission shift lock solenoid is opened or shorted to ground the shift lever will not lock in the PARK position.
    • 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 in Wiring Systems.

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 ground at the control circuit of the automatic transmission shift lock control solenoid.

Step

Action

Yes

No

Schematic Reference: Shift Lock Control Schematics

Connector End View Reference: 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 Brake to Shift Relay Output Control parameter 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 controlled voltage circuit of the automatic transmission shift lock control solenoid at the connector of the automatic transmission shift lock control solenoid and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, command the Brake to Shift Relay Output Control parameter ON and OFF.

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

Go to Step 4

Go to Step 5

4

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

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

Go to Step 6

Go to Step 8

5

Test the controlled voltage supply 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 11

Go to Step 7

6

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 11

Go to Step 9

7

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 11

Go to Step 10

8

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

Did you complete the repair?

Go to Step 11

--

9

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

Did you complete the replacement?

Go to Step 11

--

10

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 11

--

11
  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