GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Turn ON the ignition, with the engine OFF.
  2. Place the shift lever in the PARK position.

Does the PRNDL display identify the PARK position?

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Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Install a scan tool.
  2. With the scan tool, observe the Park Switch Parameter in the IPC data list.

Does the scan tool display CLOSED?

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Go to Transmission Range Switch Circuit Electrical in Automatic Transmission - 4L60E

Go to Step 4

4

  1. Disconnect the park switch.
  2. Using a fused jumper wire, test between the park switch signal circuit and a good ground. Refer to Circuit Testing in Wiring Systems.
  3. With the scan tool, observe the Park Switch parameter.

Does the scan tool display CLOSED?

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Go to Step 6

Go to Step 5

5

Test the park switch signal circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 9

Go to Step 8

6

Test the ground circuit of the park switch for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 9

Go to Step 7

7

Replace the park switch. Refer to Linear Shift Assembly Replacement - On Vehicle in Steering Wheel and Column - Tilt or Linear Shift Assembly Replacement - On Vehicle in Steering Wheel and Column - Standard.

Did you complete the replacement?

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Go to Step 9

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8

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

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Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3