GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the BCM Diagnostic System Check performed?

--

Go to Step 2

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

2

Did you review the audible warnings system operation and perform the necessary inspections?

--

Go to Step 3

Go to Audible Warnings Circuit Description

3

Verify that the key-in-ignition chime is inoperative.

Does the chime operate normally?

--

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

Go to Step 4

4

  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 5

Go to Step 8

5

Inspect the connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Are the connections in need of repair?

--

Go to Step 6

Go to Step 7

6

Repair the connections at the BCM as necessary. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 16

--

7

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

Is the repair complete?

--

Go to Step 16

--

8

  1. Using a digital multimeter (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 9

Go to Step 14

9

  1. Using a digital multimeter (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 10

Go to Step 13

10

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

Was an open or high resistance found?

--

Go to Step 11

Go to Step 12

11

Repair the open or high resistance in CKT 1850 between C211 and the ignition key alarm switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 16

--

12

Replace the ignition key alarm switch. Refer to Ignition and Key Alarm Switch Assembly - Disassemble - Off Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

--

Go to Step 16

--

13

Locate and repair the open or high resistance in CKT 1850 between C211 and G207. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 16

--

14

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

Is battery voltage measured?

B+

Go to Step 15

Go to Step 5

15

Locate and repair the open or high resistance in CKT 80 between BCM connector C2 terminal B9 and C211 terminal B3. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 4