GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2005 🢒 L300/LW300 🢒 Brakes 🢒 Park Brake 🢒 DTC B3132 or B3133

Object Number: 899091 Size: MF

Circuit Description

The body control module (BCM) controls the door unlock relay. Voltage is applied to the door unlock relay through the door unlock relay control circuit when the BCM senses a door unlock switch activation or a keyless entry unlock command.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B3132 All Door Unlock Circuit Low
    • DTC B3133 All Door Unlock Circuit High

Conditions for Running the DTC

Battery positive voltage is between 9-16 volts.

Conditions for Setting the DTC
    • The BCM detects an open in the door unlock relay control. This condition must be present for more than 0.3 seconds.
    • The BCM detects a short to ground in the door unlock relay control while commanding the door unlock relay. This condition must be present for more than 0.3 seconds.

Action Taken When the DTC Sets
    • The door unlock relay will be inoperative.
    • The BCM stores either DTC B3132 or DTC B3133 in memory.

Conditions for Clearing the DTC
    • A history DTC will clear after 100 consecutive fault-free ignition cycles.
    • A scan tool may be used to clear the DTC.

Diagnostic Aids
    • The following conditions may cause the DTC to set:
       - An open or short to ground in the door unlock relay control circuit
       - A faulty door unlock relay
       - The BCM is shorted to ground internally.
    • If the DTCs are a history DTC, the fault may be intermittent. 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 noise when the door unlock relay is commanded. Command the door locks to lock and unlock. Repeat the commands as necessary.

  2. This step verifies that the BCM is providing voltage to the door unlock relay.

    3.

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

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 unlock relay ON.

Does the door unlock relay energize when commanded?

Go to Diagnostic Aids

Go to Step 3

3

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

Does the test lamp flash when the door unlock relay is commanded ON?

Go to Step 4

Go to Step 5

4

Connect a test lamp between the door unlock relay ground circuit and battery positive voltage.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

5

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

Did you find and correct the condition?

Go to Step 12

Go to Step 6

6

Inspect for poor connections at 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 12

Go to Step 9

7

Inspect for poor connections at the door 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 12

Go to Step 10

8

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

Did you complete the repair?

Go to Step 12

--

9
  1. Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
  2. Perform the setup procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

10

Replace the door unlock relay.

Did you complete the replacement?

Go to Step 12

--

12
  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