GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Vehicle Theft Deterrent (VTD) System Check?

--

Go to Step 2

Go to Vehicle Theft Deterrent (VTD) System Check

2

  1. Turn the ignition switch to OFF.
  2. Disconnect the theft deterrent relay.
  3. Connect a fused jumper between the theft deterrent relay harness connector terminal C1 and terminal A2.
  4. Attempt to start the vehicle.

Does the vehicle start?

--

Go to Step 4

Go to Step 3

3

Does the engine crank?

--

Go to Step 6

Go to Step 5

4

Measure the voltage between the theft deterrent relay connector C2 and ground while trying to start the engine.

Does the voltage measure within the specified range?

10-15 V

Go to Step 8

Go to Step 14

5

Test CKT 5 (YEL) for an open or short to ground.

Is the circuit OK?

--

Go to Step 19

Go to Step 18

6

Inspect the theft deterrent module terminals for proper connections.

Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Are the terminal connections OK?

--

Go to Step 7

Go to Step 21

7

Test CKT 139 (PNK) to the theft deterrent module for an open or short to ground.

Is the circuit OK?

--

Go to Step 23

Go to Step 22

8

Measure the voltage between the theft deterrent relay connector C2 and connector A1 while trying to start the engine.

Does the voltage measure within the specified range?

10-15 V

Go to Step 11

Go to Step 9

9

Test for an open ground in CKT 575 (YEL).

Is the circuit OK?

--

Go to Step 16

Go to Step 12

10

Test for an open or short to ground in CKT 625 (YEL/BLK).

Is the circuit OK?

--

Go to Step 16

Go to Step 17

11

Replace the theft deterrent relay. Refer to Theft Deterrent Relay Replacement

Is the replacement complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

12

Repair the open ground in CKT 575 (YEL).

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

13

Test CKT 1642 (RED) for an open or short to ground.

Is the circuit OK?

--

Go to Step 25

Go to Step 26

14

Test for an open or short to ground in CKT 806 (PPL).

Is the circuit OK?

--

Go to Vehicle Theft Deterrent (VTD) System Check

Go to Step 15

15

Repair the open or short to ground in CKT 806 (PPL). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

16

Replace the PARK/NEUTRAL position (PNP) switch. Refer to Park/Neutral Position Switch Replacement in Transmission/Transaxle.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

17

Repair the open or short to ground in CKT 625 (YEL/BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

18

Repair the open or short to ground in CKT 5 (YEL). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

19

Test CKT 6 (PPL) for an open or short to ground.

Is the circuit OK?

--

Go to Starting System Check in Engine Electrical

Go to Step 20

20

Repair the open or short to ground in CKT 6 (PPL). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

21

Repair the poor terminal contact. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

22

Repair the open or short to ground in CKT 139 (PNK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

23

Test CKT 251 (BLK/WHT) for an open or short to ground.

Is the wiring OK?

--

Go to Step 25

Go to Step 24

24

Repair the open or short to ground in CKT 251 (BLK/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

25

Replace the theft deterrent module.

Refer to Theft Deterrent Module Replacement

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

--

26

Repair the open or short to ground on CKT 1642 (RED). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

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