A Diagnostic System Check - Body Control System

A Diagnostic System Check - Body Control System (Part 1 Of 3):

A Diagnostic System Check - Body Control System (Part 2 Of 3):

A Diagnostic System Check - Body Control System (Part 3 Of 3):

A Diagnostic System Check - Body Control System:

SYSTEM DESCRIPTION
The Body Control Module (BCM) diagnostic system check is an organized approach to identify problems associated with the BCM. The BCM diagnostic system check must be the starting point for any BCM-related complaint. The BCM diagnostic system check will direct you to the next logical step in diagnosing the complaint. The BCM is a very reliable component and it is not likely the cause of the malfunction. Most BCM system malfunctions are linked to faulty wiring, connectors, and occasionally to other vehicle components. Understanding the BCM and using the diagnostic tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

DIAGNOSTIC AIDS
^ Use a J 35616-A when probing or checking electrical connector terminals. The J 35616-A prevents terminal damage, plus checks for proper terminal contact tension.
^ If the BCM malfunction is intermittent, refer to Intermittents and Poor Connections for more information.
^ Exit all scan tool tests before cycling the ignition switch to off, unless indicated by the scan tool. Follow the scan tool user's manual. Failure to follow these instructions may set DTCs, cause vehicle system malfunctions, set false DTCs, or cause scan tool malfunctions.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is on with the Body Control Module (BCM) disconnected. When BCM diagnostics and repairs are completed, refer to Computers and Control Systems for additional information on PCM related DTCs. Computers and Control Systems

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. Determines whether the Class 2 serial data link has a circuit malfunction or the BCM is not communicating with the scan tool.
4. Tests for a short to ground in circuit 2340.
5. Tests for an open in circuit 2340.
6. Tests for an open in circuit 1550.
7. Tests for an open in circuit 1037.
8. Tests for a faulty BCM.
15. Tests for BCM current DTCs stored in memory.
16. Tests for BCM history DTCs stored in memory.
19. Tests for an intermittent BCM system malfunction.