GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. This step verifies that all of the power door locks, including the endgate locks are inoperative.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

1

Did you perform the Door System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

Verify the power door locks inoperative fault is present.

Do the power door locks operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Are all of the power door locks inoperative, including the endgate locks?

Go to Step 4

Go to Step 5

4

  1. Install a scan tool.
  2. Turn On the ignition, with the engine OFF.
  3. With a scan tool, observe the Door Unlock Switch parameter in the body control module (BCM) Input data list.
  4. Actuate a door lock switch to Unlock.

Does the scan tool display change from Inactive to Active?

Go to Step 8

Go to Step 7

5

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

Did you find and correct the condition?

Go to Step 13

Go to Step 6

6

Test the appropriate door lock actuator lock control circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

7

Test the driver door lock switch lock signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 8

8

Inspect for poor connections at the I/P Fuse Block Connector C2. 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 13

Go to Step 9

9

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 13

Go to Step 11

10

Inspect for poor connections at the appropriate door lock actuator. 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 13

Go to Step 12

11

Replace the body control Module (BCM). Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 13

--

12

Replace the appropriate door lock actuator(s). Refer to Front Side Door Lock Replacement or Rear Door Lock Replacement .

Did you complete the repair?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 3