Operation CHARM: Car repair manuals for everyone.

Except For California

P0125 ECT SENSOR







Description
The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

CAUTION: Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

DTC Logic




DTC Detection Logic

Step 1-2:




Step 2 (Continued)-3:




DTC Confirmation Procedure

Diagnostic Procedure

Step 1-4:





Component Inspection

Step 1:




Step 1 (Continued):