GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the BCM diagnostic system check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System in Body Control System

2

  1. Turn the ignition switch on.
  2. While observing the turn signal lights, move the turn signal switch the left position, then to the right position.

The turn lamps should turn on and off when the turn signal switch is in either the left or right turn position.

Do the turn lamps operate as described?

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Go to Step 3

Go to Step 5

3

Test drive the vehicle.

Does the speedometer work?

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Go to Step 4

Go to Step 6

4

Check for Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTCs). Refer to Powertrain On Board Diagnostic (OBD) System Check (LX5) or Powertrain On Board Diagnostic (OBD) System Check (L36) in Engine Controls for more information.

Are there any PCM DTCs present?

--

Go to appropriate DTC table in Engine Controls

Go to Step 7

5

The turn signal reminder is inoperative due to a malfunction of the turn lamps. Refer to Interior Lamps System Check for the diagnosis and repair of the turn lamps.

Is the action complete?

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Go to Step 8

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6

The turn signal reminder is inoperative due to a malfunction of the Vehicle Speed Sensor (VSS) circuit. Refer to Powertrain On Board Diagnostic (OBD) System Check (LX5) or Powertrain On Board Diagnostic (OBD) System Check (L36) in Engine Controls for the diagnosis and repair of the VSS.

Is the action complete?

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Go to Step 8

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7

  1. Replace the BCM. Refer to Body Control Module Replacement in Body Control System for service procedures.
  2. After BCM replacement, perform the Setup New BCM procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Is the repair complete?

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Go to Step 8

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8

  1. Turn the ignition switch off.
  2. Reinstall the connectors/components removed.
  3. Check for BCM current DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying in Body Control System for procedure.

Are there any BCM current DTCs present?

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Go to Diagnostic System Check - Body Control System in Body Control System

System OK