Note. For circuit reference (Схема №4)
Circuit Description
Engine Coolant Temperature (ECT) sensor is a thermistor or a variable resistor, that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. High temperature will result in a low signal voltage. DTC will set when PCM sees an ECT sensor voltage intermittently less than 1.5 volt.
Conditions required to set DTC is
- Engine running for longer than one minute.
- ECT sensor intermittently indicates ECT greater than 302°F (150°C), about .10 volt, for 10 seconds over a 100-second period.
Diagnostic Aids
Check for faulty connections or damaged harness. Observe ECT display on scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location. Check for skewed ECT sensor. See ECT SENSOR RESISTANCE VALUES . If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.