Engine Cooling System Diagnostic Check
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 GMC Savana, 2002 Chevrolet Chevy Express, 2001 GMC Savana Special, 2001 GMC Savana Camper Special, and 2001 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC), located below steering column. Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST A: SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS.
- Using scan tool, attempt to communicate with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with specified modules, go to TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
- Select DISPLAY DTCs function on scan tool for PCM. If scan tool displays any DTCs go to next step. If scan tool does not display any DTCs, repair cooling system by symptom.
- If scan tool displays DTCs which begin with "U", go to TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS. If other DTCs are displayed, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .