GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

1

Did you perform the Door Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

  1. Roll the driver window down.
  2. Insert the ignition key in the ignition
  3. Place the ignition in the OFF position.
  4. Open all the doors and the liftgate, if equipped.
  5. Command the doors to lock with a door lock switch.

Did all the doors lock and then the driver door unlock?

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

Go to Step 3

3

  1. Install a scan tool.
  2. With a scan tool, observe the key in ignition data parameter in the body control module data list.
  3. Insert and remove the ignition key.

Does the scan tool indicate that the key in ignition data parameter is within the specified range?

Go to Step 4

Go to Step 5

4

  1. With a scan tool, observe the driver door jamb switch data parameter in the body control module data list.
  2. Open and close the driver door.

Does the scan tool indicate that the driver door jamb switch data parameter is within the specified range?

Go to Step 6

Go to Step 8

5

  1. Disconnect the BCM.
  2. Connect a test lamp between the key in ignition switch signal circuit at the BCM harness connector and B+.
  3. Insert the ignition key in the ignition.

Does the test lamp illuminate?

Go to Step 17

Go to Step 11

6

  1. Disconnect the BCM.
  2. Connect a test lamp between the secondary door latch switch signal circuit at the BCM harness connector and B+.
  3. Open and close all passenger doors one at a time.

Does the test lamp illuminate with each door open and extinguish when closed?

Go to Step 7

Go to Step 10

7

  1. Disconnect the BCM.
  2. Connect a test lamp between the cargo door/liftgate ajar switch signal circuit at the BCM harness connector and B+.
  3. Open and close the cargo door or liftgate, if equipped.

Does the test lamp illuminate with cargo door/liftgate open and extinguish when closed?

Go to Step 17

Go to Step 12

8

  1. Disconnect the BCM.
  2. Connect a test lamp between the left front door open switch signal circuit at the BCM harness connector and B+.
  3. Open and close the driver door.

Does the test lamp illuminate with driver door open and extinguish when closed?

Go to Step 17

Go to Step 9

9

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

Did you find and correct the condition?

Go to Step 23

Go to Step 13

10

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

Did you find and correct the condition?

Go to Step 23

Go to Step 14

11

Test for an open in the key in ignition switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 15

12

Test for an open in the cargo door/liftgate ajar switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 16

13

Inspect for poor connections at the driver door jamb 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 23

Go to Step 18

14

Inspect for poor connections at the passenger door jamb switch(s). 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 23

Go to Step 19

15

Inspect for poor connections at the key in ignition 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 23

Go to Step 20

16

Inspect for poor connections at the cargo door jamb/liftgate ajar 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 23

Go to Step 22

17

Inspect for poor connections at the 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 23

Go to Step 21

18

Replace the driver door jamb switch.

Did you complete the repair?

Go to Step 23

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19

Replace the passenger door jamb switch.

Did you complete the repair?

Go to Step 23

--

20

Replace the key-in-ignition switch.

Did you complete the repair?

Go to Step 23

--

21

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the repair?

Go to Step 23

--

22

Replace the cargo door/liftgate ajar switch.

Did you complete the repair?

Go to Step 23

--

23

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3