GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the left door lock switch connector.
  2. Connect a test lamp from left door lock switch connector terminal A to B+.

Does the test lamp light?

--

Go to Step 3

Go to Step 2

2

Repair the open in CKT 750, between G200 and S220.

Is the repair complete?

--

System OK

--

3

  1. Reconnect the left door lock switch connector.
  2. Using a test lamp, backprobe between body control module BCM connector C1 terminal B and ground.
  3. While observing the test lamp, move the left door lock switch to the LOCK position.

Does the test lamp light?

--

Go to Step 4

Go to Step 5

4

Repair the open in CKT 295, between the BCM and S504.

Is the repair complete?

--

System OK

--

5

  1. Test body control module connector C1 for a poor connection.
  2. If OK, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

System OK

--