GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Audible Warnings System Check before processing?

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Go to Step 2

Go to Audible Warnings System Check

2

  1. Turn the ignition switch to RUN.
  2. Enter the body control module (MALL) diagnostic mode by completing the following procedure:
  3. 2.1. Press the power unlock switch. Hold the power unlock switch.
    2.2. Cycle the headlights 6 times.
    2.3. Release the power unlock switch.
  4. The MALL module may sound a few tones upon entering the diagnostic mode. The tones are the history diagnostic trouble codes (DTCs) stored in the MALL module. Refer to Body Control System for a list of these DTCs.
  5. After the history DTC tones, the MALL goes into input/output mode.
  6. Turn on the turn signals.

Does the chime sound when the turn signal is on?

--

Go to Step 4

Go to Step 3

3

  1. Disconnect the MALL module connector C2.
  2. Measure the voltage from connector C2 terminal C12 (harness side) to ground.

Is the measured resistance more than the specified value when you turn on the turn signal?

5 V

Go to Step 8

Go to Step 6

4

Inspect CKT 817 (DK GRN/WHT) for an open.

Is the circuit OK?

--

Go to Step 5

Go to Step 7

5

Perform the vehicle speed input test.

Is the test complete?

--

Go to Audible Warnings System Check

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6

Inspect CKT 16 (PPL) for an open.

Is the circuit OK?

--

Go to Exterior Lights for Diagnosis

Go to Step 7

7

Repair the open in CKT 16 (PPL).

Is the repair complete?

--

Go to Audible Warnings System Check

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8

Inspect the MALL module connector C2 for proper terminal contact.

Is the contact OK?

--

Go to Step 9

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9

Replace the MALL module.

Is the repair complete?

--

Go to Audible Warnings System Check

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