GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: Transmission does not shift out of PARK with the brake pedal pressed and the ignition switch in ON.

1

Did you perform the Auto Trans Shift Lock Control System Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Automatic Transmission Shift Lock Control

2

  1. Turn OFF the ignition.
  2. Disconnect the auto trans shift lock control solenoid.
  3. Turn ON the ignition, with the engine OFF.
  4. Depress the brake pedal.
  5. Probe the feed circuit of the auto trans shift lock control solenoid with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

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Go to Step 3

Go to Step 6

3

Test the feed circuit of the auto trans shift lock control solenoid for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 4

4

  1. Check the auto trans shift lock control switch adjustment. Refer to Stop Lamp Switch Adjustment and Stop Lamp Switch Replacement in brakes.
  2. Inspect for poor connections at the auto trans shift lock control 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 8

Go to Step 5

5

Replace the auto trans shift lock control switch. Refer to Stop Lamp Switch Replacement in Brakes.

Did you complete the replacement?

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Go to Step 8

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6

  1. Check the auto trans shift lock control solenoid for proper adjustment. Refer to Automatic Transmission Shift Lock Control Assemble - Off Vehicle in Steering.
  2. Inspect for poor connections at the auto trans shift lock control solenoid. 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 8

Go to Step 7

7

Replace the auto trans shift lock control solenoid. Refer to Automatic Transmission Shift Lock Control Disassemble - Off Vehicle and Automatic Transmission Shift Lock Control Assemble - Off Vehicle in Steering.

Did you complete the replacement?

--

Go to Step 8

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8

Operate the vehicle within the Conditions for Running the symptom.

Does the symptom reoccur?

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Go to Step 1

System OK