GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition switch to OFF.
  2. Install a scan tool.
  3. Turn the ignition switch to RUN.
  4. Attempt to communicate with the SBM.

Does the scan tool communicate with the SBM?

--

Go to Step 2

Go to Step 3

2

Select the DISPLAY SBM DTC function on the scan tool.

Are any DTCs stored?

--

Go to Diagnostic Trouble Code (DTC) List/Type

System OK

3

Attempt to communicate with the other systems connected to the same serial data line.

Does the scan tool communicate with the other systems?

--

Go to Step 4

Go to Data Link Communications System Check

4

  1. Turn the ignition switch to OFF.
  2. Disconnect the body control module (SBM).
  3. Turn the ignition switch to RUN.
  4. Measure the voltage between the SBM C2 terminal A9 and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 6

Go to Step 5

5

Repair the open or the short to ground in CKT 530 (WHT). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

6

Measure the voltage between the SBM C2 terminal B1 and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 8

Go to Step 7

7

Repair the open or the short to ground in CKT 1240 (ORN). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

8

Measure the voltage between the SBM C1 terminal C7 and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 10

Go to Step 9

9

Repair the open or the short to ground in CKT 39 (PNK). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

10

Measure the voltage between the SBM C1 terminal C9 and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 12

Go to Step 11

11

Repair the open or the short to ground in CKT 840 (ORN). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

12

Measure the voltage between the SBM C2 terminal A12 and terminal A9.

Is the voltage within the specified range?

10-15 V

Go to Step 14

Go to Step 13

13

Repair the open in CKT 351 (BLK/WHT). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

14

Replace the SBM. Refer to Body Control Module Replacement .

Did you complete the repair?

--

Go to Step 15

--

15

  1. Turn the ignition switch off.
  2. Reconnect all of the connectors and reinstall all of the components.
  3. Clear any DTCs.

Are all of the DTCs cleared?

--

System OK

--