GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster System Check?

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Go to Step 2

Go to Instrument Cluster System Check

2

  1. Disconnect the PCM connector C1.
  2. Connect a signal generator I/P test J 33431-C to PCM connector C1, terminal 55.
  3. Connect J 33431-C ground terminal to a good chassis ground.
  4. Set the signal generator I/P tester J 33431-C to 54 mph.
  5. Turn the ignition switch to RUN.

Does the speedometer read the specified value?

54 mph

Go to Step 4

Go to Step 3

3

Inspect CKT 817 (DK GRN/WHT) for the following conditions:

  1. A short to ground
  2. A short to voltage
  3. An op

Is CKT 817 OK?

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Go to Step 6

Go to Step 5

4

  1. Inspect for a poor connection at the PCM connector C1, terminal 55.
  2. If the terminal contact is OK, refer to Engine Controls.

Did you find and correct the condition?

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Go to Instrument Cluster System Check

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5

Repair CKT 817 (DK GRN/WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems.

Did you complete the repair?

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Go to Instrument Cluster System Check

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6

  1. Inspect for a poor connection at the instrument cluster vehicle speed input terminal.
  2. If the terminal is OK, replace the instrument cluster. Refer to IP Cluster Replacement in Instrument Panel, Gauges, and Console.

Is the replacement complete?

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Go to Instrument Cluster System Check

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