DTC Troubleshooting

NOTE: Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to PRECAUTIONS FOR DTC TROUBLESHOOTING .

DTC TROUBLESHOOTING CHART

Step	Action	YES	NO
1	Was "Engine and Emission Control System Check" performed?	Go to Step 2.	Go to ENGINE AND EMISSION CONTROL SYSTEM CHECK .
2	Engine coolant temperature check With ignition switch OFF install scan tool. With ignition switch ON, check engine coolant temperature displayed on scan tool. (ECT 1) Warm up engine to normal operating temperature. Check engine coolant temperature displayed on scan tool. (ECT 2) Is difference between ECT 1 and ECT 2 less than 1°C?	Go to Step 4.	Go to Step 3.
3	Thermostat check Check thermostat referring to THERMOSTAT INSPECTION . Is thermostat in good condition?	Go to Step 4.	Replace thermostat.
4	ECT sensor circuit check With ignition switch OFF, install scan tool and disconnect ECT sensor connector (1). With ignition switch ON, check engine coolant temperature displayed on scan tool. ECT sensor temperature specifications Signal wire terminal (2) and ground wire terminal (3) in ECT sensor connector are shorted by service wire (4): 205°C Signal wire terminal (2) and ground wire terminal (3) in ECT sensor connector are opened: -40°C Is each result satisfied its specification?	Go to Step 5.	Check ECT sensor signal and ground circuits referring to Step 2 of DTC P0117/P0118: ENGINE COOLANT TEMPERATURE CIRCUIT LOW/HIGH INPUT .
5	ECT sensor performance check Check ECT sensor referring to ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION . Is check result as specified?	Substitute a known-good ECM and recheck.	Replace ECT sensor.