GM Service Manual Online
For 1990-2009 cars only

Object Number: 502385  Size: MF
Body Control Module Components
Cell 51: Body Control Module (PZM) Power and Ground (2 of 2)
Handling ESD Sensitive Parts Notice
Power Distribution Schematics
Power Distribution Schematics
Body Control System Connector End Views

Circuit Description

The body control module (PZM) may command the interior lamps through a discrete output to the courtesy lamps relay. The energized relay provides a ground for the interior lamps.

Conditions for Setting the DTC

A short to ground is tested under the following conditions:

    • The inadvertent power output is active.
    • The interior lamp output is not active.
    • PZM DTC B1971 is not current.

A short to battery is tested for under the following conditions:

    • The inadvertent power output is active.
    • The interior lamp output is not active.
    • PZM DTC B1971 is not current.

Action Taken When the DTC Sets

The PZM continues to command the requested state until the state is achieved or changed.

Conditions for Clearing the DTC

The commanded state matches the feedback state.

Step

Action

Value(s)

Yes

No

1

Was the Body Control Module Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

  1. Turn the ignition to the OFF position.
  2. Remove the courtesy relay.
  3. Connect a scan tool to the vehicle.
  4. Turn the inadvertent power ON with the scan tool.
  5. Measure voltage from the courtesy relay terminal A9 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 3

Go to Step 7

3

Measure the voltage from the courtesy relay terminal A9 to terminal B7.

Is the voltage within the specified range?

10-15 V

Go to Step 4

Go to Step 5

4

Replace the courtesy relay.

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

--

5

Test CKT 1393 (DK BLU) for an open or a short to voltage.

Was an open or a short found?

--

Go to Step 8

Go to Step 6

6

Replace the PZM. Refer to Body Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

--

7

Repair the open or the short to ground in CKT 640 (ORN).

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

--

8

Repair the open or the short in CKT 1393 (DK BLU).

Is the repair complete?

--

Go to Diagnostic System Check - Body Control System

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