GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 Escalade ESV 🢒 Vehicle Control Systems 🢒 Computer/Integrating Systems 🢒 DTC B1397

Circuit Description

The body control module (BCM) provides an internal 12-volt reference for the steering wheel controls supply voltage circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1397 Device Voltage Reference Output Circuit Low

Conditions for Running the DTC

The voltage supplied to the BCM is in the range of 9-16 volts.

Conditions for Setting the DTC

The BCM senses a short to ground in the steering wheel controls supply voltage 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.

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 steering wheel controls supply voltage 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: 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 - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 BCM connectors.
  3. Test the steering wheel controls supply voltage circuit at the BCM connector 1 for a short to ground.
  4. 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 Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Replace the BCM . Refer to Control Module References for replacement, setup, and programming.

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