GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Sunfire 🢒 Brakes 🢒 Hydraulic Brakes 🢒 DTC B3137 or B3138

Circuit Description

The body control module (BCM) controls the locking function of the door locks in parallel with the door lock switches. The ground is applied to the door lock actuator lock control circuit through the door unlock portion of the door lock/unlock relay. When the BCM applies power to the door lock relay control circuit, the door lock portion of the door lock/unlock relay switches battery positive voltage to the door lock actuator lock control circuit, energizing all of the door lock actuators to lock.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B3137 All Door Lock Circuit Low
    • DTC B3138 All Door Lock Circuit High

Conditions for Running the DTC

The BCM must be commanding the door lock relay to energize all of the door lock actuators to lock.

Conditions for Setting the DTC
    • The BCM detects an open or a short to ground in the door lock relay control circuit while commanding the door lock relay to energize all of the door lock actuators to lock.
    • The condition above must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B3137 or B3138 in memory.

Conditions for Clearing the DTC
    • An open or a short to ground in the door lock relay control circuit is no longer detected by the BCM.
    • A history DTC B3137 or B3138 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids
    • If the DTC B3137 or B3138 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 open or short to ground in the door lock relay control circuit
       - The BCM is intermittently open or shorted to ground internally

Test Description

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

  1. Listen for an audible noise when the door lock actuators are commanded to lock. Command the door lock actuators to lock and unlock. Repeat the commands as necessary.

  2. This step verifies that the BCM is providing voltage to the door lock relay control circuit.

    3.

  3. This step tests for an open in the door lock/unlock relay ground circuit.

    4.

  4. This step tests if voltage is constantly being applied to the door lock relay control circuit.

    5.

  5. This step tests for a stuck switch.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Power Door Systems Connector End Views

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 door lock/unlock relay to lock and then to unlock.

Do the door lock actuators lock and then unlock with each command?

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the door lock/unlock relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the door lock relay control circuit with a test lamp connected to a good ground.
  5. With a scan tool, command the door locks to lock.

Does the test lamp flash when the door locks are commanded to lock?

Go to Step 4

Go to Step 5

4

  1. Connect a test lamp between the door lock relay control circuit and the ground circuit of the door lock/unlock relay.
  2. With a scan tool, command the door locks to lock and then to unlock.

Does the test lamp flash with each command?

Go to Step 9

Go to Step 12

5

Does the test lamp remain illuminated with each command?

Go to Step 6

Go to Step 7

6

While observing the test lamp, disconnect each door lock switch.

Does the test lamp remain illuminated?

Go to Step 8

Go to Step 10

7

Test the door lock relay control circuit to the door lock/unlock relay for a short to ground or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

8

Test the door lock relay control circuit to the door lock/unlock relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

9

Inspect for poor connections at the harness connector of the door lock/unlock relay. 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 16

Go to Step 13

10

Inspect for poor connections at the harness connector of the appropriate door lock 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 16

Go to Step 14

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

12

Repair the ground circuit to the door lock/unlock relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

13

Replace the door lock/unlock relay.

Did you complete the repair?

Go to Step 16

--

14

Replace the appropriate door lock switch. Refer to Door Lock Switch Replacement .

Did you complete the repair?

Go to Step 16

--

15

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 16

--

16
  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