GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the BCM System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System in Body Control System

2

Was the Audible Warnings System Check performed?

--

Go to Step 3

Go to Diagnostic System Check - Audible Warnings

3

  1. Insert the key in the ignition.
  2. Turn the ignition switch to the OFF position.
  3. Using a scan tool, enter BCM Data List INPUT 1. Monitor the Key In Ignition input.

Is YES displayed?

--

Go to Step 4

Go to Step 7

4

Inspect the connections at the BCM.

Are the connections in need of repair?

--

Go to Step 5

Go to Step 6

5

Repair the connections at the BCM as necessary.

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--

6

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

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--

7

  1. Using the J 39200 DMM, backprobe C211 terminal B3 to ground.
  2. Insert the key in the ignition.
  3. Turn the ignition switch to the OFF position.

Is battery voltage displayed?

B+

Go to Step 8

Go to Step 13

8

  1. Using the J 39200 DMM, backprobe C211 terminal B3 to terminal B4.
  2. Insert the key in the ignition.
  3. Turn the ignition switch to the OFF position.

Is battery voltage displayed?

B+

Go to Step 9

Go to Step 12

9

Inspect for an open or high resistance in CKT 1850 between C211 and the key in ignition alarm switch (CKT 80 and CKT 50).

Was an open or high resistance found?

--

Go to Step 10

Go to Step 11

10

Repair the open or high resistance in CKT 1850 between C211 and the key in ignition alarm switch.

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--

11

Replace the key in ignition alarm switch.

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--

12

Locate and repair the open or high resistance in CKT 1850 between C211 and G207.

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--

13

With a J 39200 DMM connected to ground, backprobe the BCM connector C2 terminal B9 in CKT 80.

Is battery voltage measured?

B+

Go to Step 14

Go to Step 4

14

Locate and repair the open or high resistance in CKT 80 between BCM connector C2 terminal B9 and C211 terminal B3.

Is the repair complete?

--

Go to Diagnostic System Check - Audible Warnings

--