GM Service Manual Online
For 1990-2009 cars only

Important: DO NOT replace the body control module (BCM) unless a diagnostic trouble code (DTC) remains current after all the DTC tables have been executed. DO NOT replace the BCM based on history codes.

The BCM has the following characteristics:

   • Connected to the class 2 serial data link
   • Capable of setting DTCs
A history DTC code is a fault that disappears in the next ignition cycle. The history DTC codes are useful in diagnosing an intermittent problem. An explanation of these history DTCs is given in the following table:

Diagnostic Trouble Code

Explanation

Automatic Light Control

  • B2575

ALC Headlamp System Fault

  • B2577

ALC Headlamp Relay Output short to ground/open

  • B2578

ALC Headlamp Relay Output short to Battery

  • B2585

ALC Parklamp System Fault

  • B2587

ALC Parklamp Relay Output short to ground/open

  • B2588

ALC Parklamp Relay Output short to Battery

  • B2647

Ambient Light Sensor short to ground/open

  • B2648

Ambient Light Sensor short to Battery

Class 2 Serial Data

  • U1000

Loss of Class 2 Serial Data Fault (General)

  • U1016

Powertrain Control Module (PCM) Class 2 Serial Data State of Health (SOH) Fault

  • U1040

Electronic Brake Control Module (EBCM) Class 2 Serial Data State of Health (SOH) Fault

controller Memory

  • B1000

Internal body control module (BCM) Fault Detected

  • B1001

Vehicle option configuration required

Daytime Running Lamps

  • B2600

DRL Error

  • B2602

DRL Relay Output short to ground/open

  • B2603

DRL Relay Output short to Battery

Foglamps

  • B2532

Front Foglamp Relay Output short to ground/open

  • B2533

Front Foglamp Relay Output short to Battery

Fuel Sender

  • P0462

Fuel Level Sensor Signal shorted to ground

  • P0463

Fuel Level Sensor Signal open/short to Battery

Interior Lighting Control

  • B2558

Interior Lamp Control Output short to Battery

Inputs

  • B2965

Key in Ignition Fault

  • B1369

Ignition 0 Fault

  • B1374

Ignition 1 Fault (with Engine running)

  • B1379

Ignition 3 Fault

Passlock® Theft Deterrent

Refer to Theft Deterrent System

  • B2947

Passlock™ Power Output short to ground

  • B2948

Passlock™ Power Output short to Battery

  • B2957

Passlock™ Signal Data shorted to ground

  • B2958

Passlock™ Signal Data open/short to Battery

  • B2960

Passlock™ Cylinder Data incorrect

  • B3031

BCM in learn mode (current code only)

  • B3033

Tamper mode enabled

Serial Peripheral Interface (SPI)

  • U2000

Invalid BCM transmitted Serial Peripheral Interface (SPI) data

  • U2001

Invalid Instrument Cluster transmitted Serial Peripheral Interface (SPI) data

  • U2002

Serial Peripheral Interface (SPI) data input low

  • U2003

Serial Peripheral Interface (SPI) data input high

  • U2004

Serial Peripheral Interface (SPI) data output low

  • U2005

Serial Peripheral Interface (SPI) data output high

  • U2006

Serial Peripheral Interface (SPI) Clock output low

  • U2007

Serial Peripheral Interface (SPI) Clock output high

Volts Telltale

  • B1487

Generator L-terminal low

  • B1488

Generator L-terminal high

  • B1492

Generator F-terminal low

  • B1493

Generator F-terminal high