GM Service Manual Online
For 1990-2009 cars only

Test Description

The numbers below refer to the step numbers on the diagnostic table.

Important: For Diagnostic Aids, refer to Testing for Intermittent Conditions and Poor Connections and Testing for Electrical Intermittents in Wiring Systems.

  1. Scan tool should read the normal state operation.

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

Connector End View Reference: Theft Deterrent System Connector End Views

1

Did you perform the Theft Deterrent Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the suspect Door Cylinder Sw. parameter in the Driver Door Module Inputs data list.

Does the scan tool display Idle?

Go to Step 3

Go to Step 4

3

  1. With the scan tool, observe each Door Cylinder Sw. parameter in the Driver Door Module Inputs data .
  2. Insert and rotate a key to the unlock position in each door key cylinder.

Does each Door Cylinder Sw. parameter change state?

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

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Disconnect the suspect door key cylinder switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the suspect Door Cylinder Sw. parameter in the Driver Door Module Inputs data list.

Does the scan tool display idle?

Go to Step 7

Go to Step 5

5

Test the suspect door key cylinder switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

6

  1. Using a 3 amp fused jumper wire, jumper the suspect door key cylinder switch harness connector signal circuit to the suspect door key cylinder switch harness connector ground circuit.
  2. With a scan tool, observe the suspect Door Cyl. Sw. parameter in the Driver Door Module Inputs data list.

Does the scan tool display idle?

Go to Step 12

Go to Step 8

7

Inspect for poor connections at the harness connector of the suspect door key cylinder switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

8

  1. Using a 3 amp fused jumper wire, jumper the suspect door key cylinder switch harness connector signal circuit to a good ground.
  2. With a scan tool, observe the suspect Door Cyl. Sw. parameter in the Driver Door Module Inputs data list.

Does the scan tool display idle?

Go to Step 9

Go to Step 10

9

Test the suspect door key cylinder switch ground circuit for a short to voltage or an open circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

10

Test the suspect door key cylinder switch signal circuit for a short to voltage or an open circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

11

Inspect for poor connections at the harness connector for the driver door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

12

Inspect for poor connections at the harness connector for the driver door lock cylinder switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

13

Replace the driver door module. Refer to Door Control Module Replacement - Front in Doors.

Did you complete the replacement?

Go to Step 15

--

14

Replace the suspect door key cylinder switch. Refer to Door Lock Cylinder Replacement in Doors.

Did you complete the replacement?

Go to Step 15

--

15

Operate the system to verify the repair.

Did you correct the condition?

System OK

Go to Step 2