Engine Electrical Diagnostic System Check
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.
- Perform battery inspection test. See BATTERY TESTING & INSPECTION under ON-VEHICLE TESTING. After inspection, go to next step.
- Install scan tool to vehicle DLC. Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, see SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS in BODY CONTROL MODULES - CHEVY EXPRESS & SAVANNA article in COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
- Turn ignition switch to RUN position. Using scan tool, attempt to communicate with Powertrain Control Module (PCM) on class 2 serial data circuit. If scan tool communicates module, go to next step. If scan tool does not communicate with module, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS in BODY CONTROL MODULES - CHEVY EXPRESS & SAVANNA article in COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
- Using scan tool, select DISPLAY DTCs function and retrieve any PCM DTCs. Record all DTCs displayed, DTC status and module which set the DTC. If scan tool displayed DTCs, go to next step. If scan tool did not display DTCs, repair charging system by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.
- If scan tool displays DTCs which begin with "U", perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in BODY CONTROL MODULES - CHEVY EXPRESS & SAVANNA article in COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. If scan tool does not display DTCs which begin with "U", perform appropriate test in accordance with DTCs retrieved. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .