GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 Envoy XUV 🢒 DTC 🢒 DTC B1397

Circuit Description

The body control module (BCM) provides an internal 12-volt reference used in 3 separate ratiometric comparisons to determine which steering wheel control switch and what rear wiper switch position, if any, is activated.

Conditions for Running the DTC

The voltage supplied to the body control module is in the range of 9-16 volts.

Conditions for Setting the DTC

The BCM senses a short to ground in the 12-volt reference circuit, for more than 1 second.

Action Taken When the DTC Sets

The BCM will disable the output for the rest of the ignition cycle.

The steering wheel switches will not perform their function and the rear wiper will not work.

Conditions for Clearing the DTC
    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

An intermittent short to ground in the 12-volt reference circuit will set the code. Inspect for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference:

    •  Wiper/Washer Schematics in Wipers/Washer Systems
    •  HVAC Schematics in HVAC Systems
    •  Radio/Audio System Schematics in Entertainment

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the diagnostic system check for the system exhibiting the symptom?

Go to Step 2

Go to Control Module References

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Retrieve DTCs from body control module (BCM).

Is the DTC set as current?

Go to Step 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the connector 1 of the BCM.
  3. Test the 12-volt reference circuit at the BCM connector 1 for a short to ground. Refer to the following in Wiring Systems:

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Inspect for poor connections at the harness connectors of the BCM . Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Important: Perform the module programming or setup procedure, if required.

Replace the BCM . Refer to Body Control Module Replacement .

Did you complete the replacement?

Go to Step 6

--

6
  1. Reconnect all of the disconnected modules.
  2. Use the scan tool in order to clear the DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK