GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Regal 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B2747 Performance Shift Switch CKT Short/GND

Object Number: 385126 Size: SF

Circuit Description

The BCM receives a ground signal from the Electronic Traction Control Switch through circuit 1571. The BCM receives the ground signal when the ignition is RUN and the driver toggles the enable/disable mode of the traction control system from an inactive to an active state. At this point the BCM sends out a class 2 message to the EBTCM. The BCM will not sent this message again until the traction control switch input has returned to an inactive state and transitions back to an active state.

Conditions for Setting the DTC

The BCM detects a short to ground in circuit 1571 for over 5 minutes.

Action Taken When the DTC Sets

The BCM stores DTC B2747 in memory.

Conditions for Clearing the DTC
    • The BCM detects a short to ground in circuit 1571.
    • A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Using a scan tool.

Diagnostic Aids
    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent short to ground in circuit 1571.
       - The BCM is shorted to ground internally.
    • If the DTC is a history DTC, the problem may be intermittent. Try performing the tests shown while moving wiring and connectors, this can often cause the malfunction to reappear.
    • DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is on with the Body Control module (BCM) disconnected. When BCM diagnostics and repairs are completed, refer to Engine Controls for additional information on PCM related DTCs.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for ground in circuit 1571.

    2.

  2. The step determines whether the short to ground is in circuit 1571 or the Electronic Traction Control Switch.

    3.

  3. This step determines whether the malfunction is intermittent or the BCM is faulty.

Step

Action

Value(s)

Yes

No

1

Was the BCM Diagnostic System Check performed?

--

Go to Step 2

Refer to Diagnostic System Check - Body Control System

2

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the Body Control Module (BCM) connector C2.
  3. Turn the ignition switch to the On position.
  4. Using a test light, connect between the BCM harness connector C2 terminal A11 and B+.

Is the test light on?

--

Go to Step 3

Go to Step 4

3

  1. Turn the ignition switch in the OFF position.
  2. Disconnect the Electronic Traction Control Switch.
  3. Leave the test light in the same location from the previous step.

Is the test light on?

--

Go to Step 5

Go to Step 6

4

  1. Turn the ignition switch to the OFF position.
  2. Reinstall connectors/components removed.
  3. Clear BCM DTCs. Refer to Clearing DTCs .
  4. Wait 5 minutes.
  5. Check for BCM DTC's. Refer to Diagnostic Trouble Code (DTC) Displaying .

Does BCM DTC B2747 reset as a current DTC?

--

Go to Step 7

Go to Step 8

5

Repair short to ground in circuit 1571 between the BCM connector C2 terminal A11 and electronic traction control switch connector terminal D.

Is the repair complete?

--

Go to Step 9

--

6

Replace the Electronic Traction Control Switch.

Is the repair complete?

--

Go to Step 9

--

7
  1. Replace the BCM. Refer to Body Control Module Replacement for more information.
  2. After replacing the BCM, perform the Setup New BCM procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration for more information.

Is the repair complete?

--

Go to Step 9

--

8

The malfunction is not present. Refer to Diagnostic Aids for additional information regarding DTC.

Is the repair complete?

--

Go to Step 9

--

9
  1. Turn the ignition switch to the OFF position.
  2. Reinstall connectors/components removed.
  3. Turn the ignition switch to the On position.
  4. Clear BCM DTCs. Refer to Clearing DTCs for more information.
  5. Check for BCM DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying for more information.

Are there current BCM DTCs set?

--

Refer to Diagnostic System Check - Body Control System

System OK