GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. This step tests for voltage at the coil side of the lock cylinder relay.

  2. This step verifies that the dash integration module (DIM) is providing ground to the lock cylinder relay.

  3. This step tests if ground is constantly being applied to the ignition lock cylinder control actuator.

Step

Action

Yes

No

Schematic Reference: Column/Ignition Lock Schematics

Connector End View Reference: Steering Wheel and Column Connector End Views

1

Operate the system.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 2

2

  1. Push the ignition lock cylinder control actuator release button which is on the underside of the ignition key cylinder.
  2. Turn the key to the OFF position and remove the key.

Were you able to turn the key to the OFF position and remove the key?

Go to Step 3

Go to Lock System Does Not Lock

3

  1. Turn OFF the ignition.
  2. Disconnect the ignition lock cylinder control actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the battery positive voltage circuit and the ignition key/shifter interlock switch supply voltage circuit of the ignition lock cylinder control actuator with a test lamp.

Does the test lamp illuminate?

Go to Step 8

Go to Step 4

4

Probe the battery positive voltage circuit of the ignition lock cylinder control actuator with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 12

5

  1. Turn OFF the ignition.
  2. Reconnect the ignition lock cylinder control actuator connector.
  3. Disconnect the automatic transmission shift lock actuator connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Connect a test lamp between the ignition key/shifter interlock switch supply voltage circuit and the ignition lock cylinder control switch signal circuit.

Does the test lamp illuminate?

Go to Step 10

Go to Step 6

6

Probe the ignition lock cylinder control switch signal circuit and with a test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 13

Go to Step 7

7

Test the ignition lock cylinder control switch signal circuit for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 11

8

Test the ignition key/shifter interlock switch supply voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 9

9

Inspect for poor connections at the ignition lock cylinder control actuator. 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 17

Go to Step 14

10

Inspect for poor connections at the automatic transmission shift lock actuator. 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 17

Go to Step 15

11

Inspect for poor connections at the harness connector of the dash integration module (DIM). 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 17

Go to Step 16

12

Repair the battery positive voltage circuit of the ignition lock cylinder control actuator. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

13

Repair the voltage supply circuit of the ignition lock cylinder control switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

--

14

Replace the ignition lock cylinder control actuator.

Did you complete the replacement?

Go to Step 17

--

15

Replace the automatic transmission shift lock actuator. Refer to Automatic Transmission Shift Lock Actuator Replacement .

Did you complete the replacement?

Go to Step 17

--

16

Important: Perform the set up procedure for the DIM .

Replace the DIM. Refer to Dash Integration Module Replacement in Computer/Integrating Systems.

Did you complete the replacement?

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3