GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

DEFINITION: The ignition lock cylinder will not allow the key to be turned to the LOCK position.

1

Did you review the Steering Wheel and Column Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Steering Wheel and Column

2

Verify that the lock system does not lock.

Does the lock system lock?

System OK

Go to Step 3

3

Rotate the steering wheel and attempt to turn the key to the LOCK position.

Are you able to turn the key to the LOCK position?

System OK

Go to Step 4

4

Does the vehicle have an automatic transmission?

Go to Step 5

Go to Step 8

5

  1. Shift the automatic transmission shift lever to Park.
  2. Rotate the steering wheel and attempt to turn the key to the LOCK position.

Are you able to turn the key to the LOCK position?

System OK

Go to Step 6

6

Inspect the park lock micro switches and the wiring harness for damage. Refer to Automatic Transmission Shift Lock Actuator Replacement in Shift Lock Control.

Are the park lock micro switches or the wiring harness damaged?

Go to Step 10

Go to Step 7

7

Inspect the ignition lock cylinder solenoid for damage.

Is the ignition lock cylinder solenoid damaged?

Go to Step 11

Go to Step 8

8

Inspect the ignition switch for damage.

Is the ignition switch damaged?

Go to Step 11

Go to Step 9

9

Important: Attempting theft or improperly removing the ignition lock cylinder breaks the barrel locking latch in the ignition lock cylinder. A broken barrel locking latch permanently prevents rotation or removal of the ignition lock cylinder.

Inspect the lock cylinder for damage.

Is the lock cylinder damaged?

Go to Step 12

Go to Step 2

10

Replace the park lock micro switch wiring harness. Refer to Automatic Transmission Shift Lock Actuator Replacement in Shift Lock Control.

Did you complete the repair?

Go to Step 14

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11

Replace the ignition switch and/or the ignition lock cylinder solenoid as necessary. Refer to Ignition and Start Switch Replacement .

Did you complete the repair?

Go to Step 14

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12

Replace the lock cylinder, if possible. Refer to Ignition Lock Cylinder Replacement .

Did you complete the repair?

Go to Step 14

Go to Step 13

13

Replace the following components:

    • The steering column. Refer to Steering Column Replacement .
    • The ignition lock cylinder. Refer to Ignition Lock Cylinder Replacement .
    • The ignition switch and the ignition lock cylinder solenoid, if equipped. Refer to Ignition and Start Switch Replacement .

Did you complete the repair?

Go to Step 14

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14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2