GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The rear compartment lid release circuit is completed by the BCM when it receives a truck release request from the RCDLR trunk release button and the vehicle is in the PARK position. The BCM momentarily grounds circuit 253 energizing the rear compartment lid release relay.

Conditions for Setting the DTC

    • The BCM detects a short to B+ in circuit 253 while attempting to ground circuit 253.
    • The BCM test for a short to B+ in circuit 253 only when attempting to release the rear compartment .
    • All conditions must be present for more than 0.15 seconds.

Action Taken When the DTC Sets

    • The BCM stores DTC B3268 in memory.
    • The BCM turns off its output to the rear compartment lid release.

Conditions for Clearing the DTC

    • When the ignition switch is cycled from off to on, the current DTC is cleared. If the fault is present at the next trunk release activation, this DTC sets as current.
    • 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 B+ in circuit 253.
       - The BCM is shorted to B+ internally.
       - The rear compartment lid release relay coil is shorted to B+ 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 short to B+ in circuit 253.

  2. The step determines whether the circuit 253 has a short to B+ or the BCM is faulty.

  3. This step checks BCM DTC B3268 and checks for BCM DTC B3268 to set again.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Rear End

2

  1. Disconnect the rear compartment lid release relay connector.
  2. Using a test light connect between the rear compartment lid release relay harness connector terminal C2 and ground.

Does the test light illuminate?

--

Go to Step 3

Go to Step 4

3

  1. Leave the test light in the same location from the previous step.
  2. Turn the ignition switch in the OFF position.
  3. disconnect the BCM connectors.
  4. Turn the ignition switch in the ON position.

Does the test light illuminate?

--

Go to Step 5

Go to Step 6

4

Replace the rear compartment lid release relay.

Has the repair been completed?

--

Go to Step 9

--

5

Repair a short to B+ in circuit 253.

Has the repair been completed?

--

Go to Step 9

--

6

  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.
  5. Press the rear release button on the RKE transmitter.
  6. Check for BCM DTCs.

Does the DTC B3268 reset as a current DTC?

--

Go to Step 7

--

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.

Is the repair completed?

--

Go to Step 9

--

8

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

Has the repair been completed?

--

Go to Step 9

--

9

  1. Turn the ignition switch to the OFF position.
  2. Reinstall connectors/components removed.

Verify that the system operates properly.

Does the system operate properly?

--

System OK

Go to Diagnostic System Check - Body Rear End