Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport and 2002 Isuzu Rodeo. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use extreme caution when opening cooling system to measure coolant temperature.
- Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
- If any related ECT DTCs are set, diagnose affected DTC before proceeding. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no related ECT DTCs are set, go to next step.
- Allow engine to cool. Check coolant level. If coolant level is okay, go to next step. If coolant level is low, go to step 9 .
- Start engine and allow it to idle. Using scan tool, monitor ENG COOL TEMP parameter. If temperature increases to 70°F (21°C) within 2 minutes, check for intermittent problem. See DIAGNOSTIC AIDS . If specified temperature is not reached within 2 minutes, go to next step.
- Check thermostat operation. If thermostat is operating correctly, go to next step. If thermostat is not operating correctly, go to step 9 .
- Using thermometer, measure coolant temperature. Compare actual coolant temperature with scan tool ECT sensor parameter. If temperatures are close in value, go to step 9 . If temperatures are not close in value, go to next step.
- Turn ignition off. Disconnect PCM 32-pin harness connectors C-2 (White) and C-3 (Blue). PCM is located under center console in front of shifter. Using DVOM, measure resistance between PCM harness connector C-2 terminal D8 (Green wire) and PCM harness connector C-3 terminal E9 (Blue/Red wire). See Figure . Compare DVOM readings with ENGINE COOLANT TEMPERATURE SENSOR SPECIFICATIONS table in TEST DESCRIPTION. If measured resistance is as specified, go to step 12 . If measured resistance is not as specified, go to next step.
- Check for open, short to ground or short to voltage in Blue/Red and Green wires between ECT sensor and PCM. See WIRING DIAGRAMS article. If a problem was found, go to step 10 . If no problem was found, go to step 11 .
- Repair cooling system as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM.
- Repair wiring or terminals as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM.
- Replace ECT sensor. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM.
- Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT under POWERTRAIN CONTROL MODULE. After repair is complete, see VERIFYING VEHICLE REPAIR under SELF-DIAGNOSTIC SYSTEM.