Cooling System Diagnostic System Check
- Connect scan tool to Data Link Connector (DLC). See Figure . If scan tool powers up, go to next step. If scan tool does not power up, go to SCAN TOOL DOES NOT POWER UP under SELF-DIAGNOSTIC SYSTEM in BODY CONTROL MODULES - DEVILLE article.
- Turn ignition on. Attempt to establish communication with Powertrain Control Module (PCM) and Instrument Panel Cluster (IPC). If scan tool communicates with both modules, go to next step. If scan tool does not communicate with both modules, go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SELF-DIAGNOSTIC SYSTEM in BODY CONTROL MODULES - DEVILLE article.
- Select display DTCs function for PCM. If any DTCs are set for PCM, go to appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are set, go to step 5 .
- Select display DTCs function for IPC. If any DTCs are set for IPC, go to INSTRUMENT PANEL CLUSTER DIAGNOSTIC TROUBLE CODE DEFINITIONS table. If no DTCs are set, go to next step.
- If scan tool does not display and DTCs that begin with "U", attempt to diagnose by symptom. See SYMPTOM TESTS . If scan tool displays any DTCs that begin with "U" go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SELF-DIAGNOSTIC SYSTEM in BODY CONTROL MODULES - DEVILLE article.