GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics and Door Control Module 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

Verify that the power door locks are inoperative from one door or switch.

Do the power door locks operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Is the passenger door lock switch the inoperative switch?

Go to Step 4

Go to Step 6

4

Are both the lock and unlock functions inoperative?

Go to Step 8

Go to Step 5

5

Is the lock function inoperative?

Go to Step 9

Go to Step 10

6

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the door lock switch parameter in the Driver Door Switch assembly (DDSA) data list.
  4. Activate the driver door lock switch to the Lock and Unlock positions.

Does the scan tool display Idle?

Go to Step 11

Go to Step 7

7

Does the scan tool display Lock?

Go to Step 12

Go to Step 13

8

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

Did you find and correct the condition?

Go to Step 20

Go to Step 14

9

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

Did you find and correct the condition?

Go to Step 20

Go to Step 15

10

Test the passenger door lock switch unlock signal circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 15

11

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

Did you find and correct the condition?

Go to Step 20

Go to Step 16

12

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

Did you find and correct the condition?

Go to Step 20

Go to Step 15

13

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

Did you find and correct the condition?

Go to Step 20

Go to Step 15

14

Inspect for poor connections at the harness connector of the passenger 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 20

Go to Step 17

15

Inspect for poor connections at the harness connector of the appropriate door module. 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 20

Go to Step 18

16

Inspect for poor connections at the harness connector of the driver 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 20

Go to Step 19

17

Replace the passenger door lock switch. Refer to Door Lock Switch Replacement - Passenger Front .

Did you complete the replacement?

Go to Step 20

--

18

Replace the appropriate door module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

Go to Step 20

--

19

Replace the driver door lock switch. Refer to Front Door Switch Replacement .

Did you complete the replacement?

Go to Step 20

--

20

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2