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. Disconnect the body control module (SBM) connector C1.
  2. Set the headlamp switch to PARK or HEAD.
  3. Use a J 39200 digital multimeter (DMM) in order to measure the voltage at SBM connector C1 terminal C12.

Is the voltage within the specified range?

12-15 V

Go to Step 3

Go to Step 6

3

Test SBM connector C1 terminal contact.

Is the terminal contact OK?

--

Go to Step 5

Go to Step 4

4

Repair SBM connector C1 terminal contact.

Is the repair complete?

--

Go to Diagnostic System Check - Instrument Cluster

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5

Replace the SBM.

Is the repair complete?

--

Go to Diagnostic System Check - Instrument Cluster

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6

Test CKT 549 (PPL/WHT) for an open or short to ground.

Is the circuit OK?

--

Go to Step 8

Go to Step 7

7

Repair the open or short to ground in CKT 549 (PPL/WHT).

Is the repair complete?

--

Go to Diagnostic System Check - Instrument Cluster

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8

Test the lamp control module (LCM) connector for proper terminal contact.

Is the terminal contact OK?

--

Go to Step 10

Go to Step 9

9

Repair the connector terminal contact.

Is the repair complete?

--

Go to Diagnostic System Check - Instrument Cluster

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10

Replace the lamp control module.

Is the replacement complete?

--

Go to Diagnostic System Check - Instrument Cluster

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