Did you perform the Instrument Cluster Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

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

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 (4.3L) in Automatic Transmission - 4L60E

Go to Step 4

1. Disconnect the park switch.
2. Connect a fused jumper wire 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

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

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

Replace the park switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission - 4L60E.

Did you complete the replacement?

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Go to Step 9

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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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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3