Self-Diagnostic System: Notes

WARNING: This page is about a different car, the 2003 GMC Savana Special, 2003 GMC Savana Camper Special, 2003 GMC Savana, and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The following test is written specifically for Tech 2 scan tool. A generic scan tool may not be capable of performing all necessary test functions.

Begin system diagnosis with engine electrical diagnostic system check. Diagnostic system check will provide following information:

Identification of control module(s) which command system.
Ability of control module(s) to communicate through serial data circuit.
Identification of any stored DTCs and their current status.

Using diagnostic system check will identify correct procedure for diagnosing system and where procedure is located. This article only covers the portion of those systems which relates to charging system diagnosis. For further information, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.