Diagnostic Tests: Notes

NOTE: Diagnostic Trouble Code (DTC) tests are written specifically for use with GM Tech 2 scan tool. Generic scan tool can be used but may have limited functions. This article only covers portion of those systems and DTC tests which relate to analog instrument panel system diagnosis.

NOTE: Use adapter from Terminal Test Adapter Kit (J-35616-A) connected to DVOM when making all measurements.

NOTE: Unless otherwise specified, make all voltage and resistance measurements with a Digital Volt-Ohmmeter (DVOM) having an input impedance of 10 megohms or greater.

NOTE: Do not replace Body Control Module (BCM) unless a DTC remains current after all DTC repairs have been performed. Do not replace BCM if only history DTCs are set.

NOTE: Always check module ground and power circuits prior to replacing a control module. See DATA LINK CONNECTORS, GROUND DISTRIBUTION and/or POWER DISTRIBUTION articles in WIRING DIAGRAMS.