GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you review the Automatic Transmission Shift Lock Control Circuit Description and the Automatic Transmission Shift Lock Control Description ?

Go to Step 2

Go to Symptoms - Automatic Transmission Shift Lock Control

2

  1. Turn the ignition switch to the ON position.
  2. Attempt to move the manual selector from the P position.

Can you move the manual selector from the P position?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Disconnect the shift lock relay.

Does the shift lock solenoid disengage?

Go to Step 4

Go to Step 7

4

Test for a short to voltage in the GRN/WHT wire between the shift lock relay connector cavity 3 and S213. Refer to Circuit Testing in Wiring Systems.

Is a short to voltage present?

Go to Step 6

Go to Step 5

5

Replace the shift lock relay.

Is the repair complete?

Go to Step 10

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6

Repair the short to voltage in the GRN/WHT wire between the shift lock relay connector cavity 3 and S213. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 10

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7

Test for a short to voltage in the BLU/GRN wire between the shift lock relay connector cavity 1 and the shift lock solenoid.

Is a short to voltage present?

Go to Step 8

Go to Step 9

8

Repair the short to voltage in the BLU/GRN wire between the shift lock relay connector cavity 1 and the shift lock solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 10

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9

Replace the shift lock solenoid. Refer to Brake Transmission Shift Interlock Solenoid Replacement in Automatic Transmission.

Is the repair complete?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3