DTC Confirmation Test (DTC P0125)

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Malfunction is detected when ECT sensor voltage is incorrect, based on engine run time (engine coolant temperature too low). Possible causes are:

High resistance in ECT sensor circuit.
Defective ECT sensor.
Stuck open thermostat.

Connect scan tool to Data Link Connector (DLC). See Figure . Turn ignition on. Using scan tool, select DATA MONITOR and check engine coolant temperature. If coolant temperature is greater than 50°F (10°C), system is okay. If coolant temperature is less than 50°F (10°C), start engine and let idle. Ensure coolant temperature is less than 50°F (10°C). Start engine and let it idle for 65 minutes. DTC will set if coolant temperature does not increase to greater than 50°F (10°C). If first trip DTC is sets, perform DIAGNOSTIC PROCEDURE . If first trip DTC is not set, problem may be intermittent. See TESTING PROCEDURE .