GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuse 10 in the fuse block.

Is fuse 10 open?

--

Go to Step 2

Go to Step 3

2

  1. Replace fuse 10.
  2. Inspect fuse 10 again.

Is fuse 10 open again?

--

Go to Step 11

Go to Step 3

3

Do the following components operate normally?

  1. Radio hold time/memory presents
  2. Audible warnings (fasten belt reminder chime, key-in ignition chime).

--

Go to Step 4

Go to Step 12

4

Inspect fuse 12 in the fuse block.

Is fuse 12 open?

--

Go to Step  5

Go to Step 6

5

  1. Replace fuse 12.
  2. Turn the ignition switch to the RUN position.
  3. Inspect fuse 12 again.

Is fuse 12 open again?

--

Go to Step 13

Go to Step 6

6

  1. Turn the ignition switch to the LOCK position.
  2. Turn the ignition switch to the RUN position.
  3. Observe the Service Engine Soon (MIL) indicator lamp in the instrument cluster.

Does the MIL light?

--

Go to Step 7

Go to Step 14

7

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the theft deterrent module.
  3. Use a test light to probe between the theft deterrent module harness connector terminal A1 and the ground.

Does the test light illuminate?

--

Go to Step 8

Go to Step 15

8

  1. Turn the ignition switch to the RUN position.
  2. Use a test light to probe between the theft deterrent module harness connector terminal A2 and the ground.

Does the test light illuminate?

--

Go to Step 9

Go to Step 16

9

Use a test light to probe between B+ and the theft deterrent module harness connector terminal B5.

Does the test light illuminate?

--

Go to Step 10

Go to Step 17

10

  1. Install a fused jumper between the theft deterrent module harness connector terminal A5 and ground.
  2. Turn the ignition switch to the run position.

Does the security indicator illuminate?

Less than 2 ohms

Go to Step 18

Go to Step 19

11

Repair a short to ground in CKT 640.

Has the repair been made?

--

Go to Step 20

--

12

Inspect for the following connections:

  1. Poor connection or an open in the power feed CKT to fuse 10 in Wiring Systems for the schematic.
  2. Inspect G201 for a clean tight connection.

Is the action complete?

--

Go to Step 20

--

13

Repair a short to ground in CKT 339 in Wiring Systems for the schematic.

Has the repair been made?

--

Go to Step 20

--

14

  1. Inspect for a poor connection or an open in the power feed CKT to fuse 12 in Wiring Systems for the schematic.
  2. Make repairs as needed.

Is the action complete?

--

Go to Step 20

--

15

Repair a poor connection or an open in CKT 640.

Has the repair been made?

--

Go to Step 20

--

16

Repair a poor connection or an open in CKT 339 in Wiring Systems for the schematic.

Has the repair been made?

--

Go to Step 20

--

17

  1. Repair a poor connection or an open in CKT 1550.
  2. Inspect for a clean tight G201.

Has the repair been made?

--

Go to Step 20

--

18

  1. Inspect the theft deterrent module harness connector for poor terminal contact.
  2. If no problem is found replace the theft deterrent module. Refer to Theft Deterrent Module Replacement .

Has the repair been made?

--

Go to Step 20

--

19

Repair a poor connection or an open in CKT 728.

Has the repair been made?

--

Go to Step 20

--

20

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the theft deterrent module.
  3. Turn the ignition switch to the bulb check position.

Does the security indicator illuminate?

--

Go to Step 21

Go to Instrument Cluster System Check

21

Turn the ignition switch to the RUN position.

Does the engine start?

--

System OK

Go to Vehicle Theft Deterrent (VTD) System Check