GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Definition: The BCM sounds the headlamps-on reminder when one or more of the following conditions are present:

    • The driver's door is closed
    • The headlamp switch is in the OFF position
    • The key is removed from the ignition switch

1

Was the Body Control Module (BCM) System Check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Turn off the instrument panel dimmer switch.
  2. Turn on the interior lamps override switch, enabling the interior courtesy lamps.
  3. Turn the ignition switch to the RUN position.
  4. Lower the driver's window in order to prevent lockout.
  5. Close all of the vehicle doors.

Are the courtesy lamps off?

--

Go to Step 3

Go to Step 6

3

  1. Turn the headlamp switch to the OFF position.
  2. Using a test lamp, backprobe between the BCM connector C2 terminal D5 and ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 4

4

  1. Disconnect the headlamp switch electrical connector.
  2. Using a test lamp, connect between terminal O of the harness connector for the headlamp and instrument panel dimmer switch and ground.

Does the test lamp light?

--

Go to Step 5

Go to Step 8

5

  1. Disconnect the BCM connector C2.
  2. Using a J 39200 digital multimeter (DMM), measure the resistance between the BCM harness connector C2 terminal D5 and the terminal P of the harness connector for the headlamp and instrument panel dimmer switch.

Does the test lamp light?

2 ohms

Go to Step 9

Go to Step 10

6

The headlamps-on reminder sounds with the driver's door closed due to a malfunction between the BCM and the driver's door-lock-ajar switch. Refer to Interior Lights.

Is the action complete?

--

Go to Step 11

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7

  1. Inspect the BCM connector C2 terminal D5 for a poor connection.
  2. If the connection is OK, replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

Go to Step 11

--

8

Repair poor connection or open in CKT 1340.

Is the repair complete?

--

Go to Step 11

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9

  1. Inspect the terminal P of the headlamp and instrument panel dimmer switch connector for a poor connection.
  2. If the connection is OK, replace the headlamp and IP lamp dimmer switch. Refer to Headlamp Switch Replacement in Lighting Systems.

Is the repair complete?

--

Go to Step 11

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10

Repair the poor connection or open in CKT 1872.

Is the repair complete?

--

Go to Step 11

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11

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall the connectors and the components which you removed.
  3. Turn the ignition switch to the RUN position for 6 seconds.
  4. Remove the BCM PRGRM fuse.
  5. Turn the ignition switch to the ACC position. The BCM sounds the chime several times equivalent to the BCM type which is installed on the vehicle.
  6. Within 1 second, turn the ignition switch from the ACC position to the LOCK position, then back to the ACC position. The BCM sounds any DTCs stored.

Are any BCM DTCs present?

--

Go to Diagnostic System Check - Body Control System

System OK