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 Symptoms - Audible Warnings

3

Verify that the turn signal 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 RUN position.
  3. Using a scan tool, enter BCM Data List INPUT 2.
  4. Monitor the left turn signal and the right turn signal.
  5. Move the turn signal switch to the LEFT and the RIGHT positions.

Does the scan tool alternate between ON and OFF for both parameters in relation to the turn signal switch position?

--

Go to Step 5

Go to Step 9

5

  1. Drive the vehicle with the scan tool installed.
  2. Enter BCM Data List DATA.
  3. Monitor the vehicle speed.

Is the vehicle speed displayed for the vehicle in motion?

--

Go to Step 6

Go to Step 11

6

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 7

Go to Step 8

7

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

Is the repair complete?

--

Go to Step 12

--

8

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

Is the repair complete?

--

Go to Step 12

--

9

  1. Using a digital multimeter (DMM), backprobe the BCM connector C1 terminal B6 (left turn signal) and terminal B7 (right turn signal) to ground.
  2. Measure the voltage.
  3. Select the 40 Volt Range.
  4. Turn the ignition switch to the RUN position.
  5. Operate the turn signal switch.
  6. With the turn signals operating, push the MIN/MAX button 4 times.
  7. Avg. is displayed at the top of the meter.

Is approximately 1/2 battery voltage displayed on both terminals?

--

Go to Step 6

Go to Step 10

10

Repair the open or the high resistance in CKT 1414 or CKT 1415 as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 12

--

11

Repair the open or the high resistance in CKT 817 between BCM connector C2 terminal B1 and VCM connector C4 terminal 3. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 4