GM Service Manual Online
For 1990-2009 cars only

Object Number: 610398  Size: MF

Circuit Description

The Body Control Module (BCM) controls the operation of the seat belt indicator. The seat belt indicator is located in the instrument cluster. The BCM turns ON the seat belt indicator by sending voltage through the seat belt indicator supply voltage circuit. The seat belt indicator receives ground through the ground circuit.

The BCM turns ON the seat belt indicator for 55 seconds when the following conditions are met:

    • The ignition switch is ON
    • The driver's seat belt releases (unfastens).

If the driver's seat belt is fastened during the 55 second period, the BCM turns OFF the seat belt indicator. If the driver's seat belt releases anytime during the same ignition cycle, the BCM turns ON the seat belt indicator again for 55 seconds.

Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The BCM detects a short to B+ or ground in the seat belt indicator supply voltage circuit.

Action Taken When the DTC Sets

    • The seat belt indicator lamp does not turn on when the seat belt indicator supply voltage circuit shorts to ground.
    • The seat belt indicator lamp stays on at all times when the seat belt indicator supply voltage circuit shorts to B+.

Conditions for Clearing the DTC

    • A short to B+ or ground in the seat belt indicator supply voltage circuit is no longer present between the BCM and the instrument cluster.
    • After you complete the repairs, clear the DTC. Refer to Diagnostic Trouble Code (DTC) Clearing .

Diagnostic Aids

    • Inspect for a short to ground in the seat belt indicator supply voltage circuit.
    • Inspect for a short to B+ in the seat belt indicator supply voltage circuit.
    • Inspect for an internal short to ground or short to B+ within the instrument cluster circuity.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step determines if there is a short to ground or a short to B+ in the seat belt indicator supply voltage circuit.

  2. This step determines if there is a short to B+ in the seat belt indicator supply voltage circuit or if there is a malfunctioning BCM.

  3. This step determines if there is a short to B+ in the seat belt indicator supply voltage circuit or if there is a malfunctioning instrument cluster.

  4. This step determines if there is a short to ground in the seat belt indicator supply voltage circuit or if there is a malfunctioning instrument cluster.

Step

Action

Value(s)

Yes

No

1

Did you perform A Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Turn ON the ignition, with the engine OFF.
  2. Note the seat belt indicator while turning ON the ignition.

Does the seat belt indicator stay ON continuously?

--

Go to Step 3

Go to Step 8

3

  1. Turn OFF the ignition.
  2. Disconnect the BCM connector C2.
  3. Turn ON the ignition, with the engine OFF.

Does the seat belt indicator stay ON continuously?

--

Go to Step 5

Go to Step 4

4

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 10

--

5

  1. Disconnect the instrument cluster connector C1.
  2. Use the J 39200 Digital Multimeter (DMM) to measure the voltage between the seat belt indicator supply voltage circuit and a known good ground.

Does the voltage measure less than the specified value?

1 V

Go to Step 6

Go to Step 7

6

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges, and Console.

Did you complete the replacement?

--

Go to Step 10

--

7

Locate and repair a short to B+ in the seat belt indicator supply voltage circuit. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 10

--

8

  1. Disconnect the body control module (BCM) connector C2.
  2. Disconnect the instrument panel connector C1.
  3. Use the J 39200 Digital Multimeter (DMM) to measure the resistance between the seat belt indicator supply voltage circuit and a known good ground.

Does the resistance measure less than the specified value?

OL

Go to Step 9

Go to Step 6

9

Locate and repair the short to ground in the seat belt indicator supply voltage circuit. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 10

--

10

  1. Reconnect all components.
  2. Verify that all components and connectors are properly mounted.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to Diagnostic System Check

System OK