Test Z: Engine Coolant Temperature Indicator Always On

If engine cooling diagnostic system check has been performed, go to next step. If engine cooling diagnostic system check has not been performed, see ENGINE COOLING DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in BODY CONTROL MODULES - AZTEK article.
Observe instrument cluster while starting engine. If engine coolant temperature indicator illuminates, go to next step. If engine coolant temperature indicator does not illuminate, concern may be intermittent. For aid in diagnosing intermittent problems, see PROBLEM DIAGNOSIS under INTERMITTENTS.
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. Using scan tool, observe ENGINE COOLANT TEMPERATURE parameter in Powertrain Control Module (PCM) data list. If scan tool parameter does not indicate that coolant temperature is within temperature range shown on temperature gauge, go to next step. If scan tool indicates that coolant temperature is within temperature range shown on temperature gauge, repair engine overheating concern.
Replace IPC. See INSTRUMENT PANEL CLUSTER under REMOVAL & INSTALLATION. After repairs are made, go to next step.
Operate system to verify repairs. If system operates normally, test is complete. If system does not operate normally, go to step 2.