GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Body Systems 🢒 Vehicle Access 🢒 Power Door Lock Key Cylinder Switches Inoperative

Diagnostic Aids

The key cylinder switches are contained within the driver door lock actuator. The switches are not serviced separately from the door lock actuators. Export vehicles are equipped with the Deadbolt feature. For more information on door lock features, refer to Power Door Locks Description and Operation .

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step inspects to see that the driver door module recognizes the key cylinder switch input.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics

Connector End View Reference: Vehicle Access Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Does the door lock key cylinder operate as described in the Description and Operation?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the Key Cylinder Lock/Unlock parameter in the Driver Door Module (DDM), Inputs list as the key is cycled between the lock and unlock positions.

Does the Key Cylinder Lock/Unlock parameter change to the appropriate state as the key is cycled?

Go to Step 8

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the driver door lock actuator harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Install a 3-amp fused jumper wire between the appropriate key cylinder switch signal circuit of the harness connector and a good ground.
  5. With the scan tool, observe the Key Cylinder Lock/Unlock parameter.

Does the Key Cylinder Lock/Unlock parameter change to the appropriate state?

Go to Step 5

Go to Step 6

5
  1. Install a 3-amp fused jumper wire between the appropriate key cylinder switch signal and ground circuits of the harness connector.
  2. With the scan tool, observe the Key Cylinder Lock/Unlock parameter.

Does the Key Cylinder Lock/Unlock parameter change to the appropriate state?

Go to Step 7

Go to Step 9

6

Test the appropriate key cylinder switch signal circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 8

7

Inspect for poor connections at the harness connector of the driver door lock actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

8

Inspect for poor connections at the harness connector of the DDM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

9

Repair the open ground circuit of the harness connector. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 12

--

10

Replace the driver door lock actuator. Refer to Front Side Door Latch Replacement .

Did you complete the replacement?

Go to Step 12

--

11

Replace the DDM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2