GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The body control module (BCM) provides a low side drive output that controls the trunk release relay.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3265 Trunk Relay Output

Conditions for Running the DTC

The only requirements are valid operating voltage and ground.

Conditions for Setting the DTC

One of the following conditions exist for more than 1 second:

    • The BCM detects a short to battery in the trunk relay control when output is active.
    • The BCM detects a short to ground or an open in the trunk relay control when output is inactive.

Action Taken When the DTC Sets

The BCM disables the trunk relay control until the next ignition cycle.

Conditions for Clearing the DTC

    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Test Description

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

  1. During the trunk release relay operation, listen for an audible click. Command the ON and OFF states. Repeat the commands, as necessary.

  2. This step tests for an open in the trunk release relay battery positive voltage circuit.

  3. This step tests for a short to power in the signal circuit to the trunk release relay.

  4. This step verifies the BCM is providing a ground to the trunk release relay.

Step

Action

Yes

No

Schematic Reference: Liftgate Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, command the trunk release relay ON and OFF.

Does the trunk release relay turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the trunk release relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the battery positive circuit of the trunk release relay with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 12

4

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the trunk release relay control circuit of the trunk release relay with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

5

  1. Connect a test lamp between the control circuit of the trunk release relay and the battery positive voltage circuit of the trunk release relay.
  2. With a scan tool, command the trunk release relay ON and OFF.

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

Go to Step 10

Go to Step 6

6

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 9

7

Test the control circuit of the trunk release relay for a short to ground. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

8

  1. Turn ON the ignition, with the engine OFF.
  2. Test the control circuit of the trunk release relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

9

Test the trunk release relay control circuit for an open. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

10

Inspect for poor connections at the trunk release relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

11

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.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

12

Repair the open in the trunk release relay battery positive voltage circuit. Refer to Wiring Repairs.

Did you complete the repair?

Go to Step 15

--

13

Replace the trunk release relay.

Did you complete the replacement?

Go to Step 15

--

14

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

--

15

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK