An Engine Coolant Temperature Sensor (ECTS) monitors the temperature of the coolant. This input is used by the PCM for engine control and as an enabling criteria for same diagnostics. The air flow coming into the engine is accumulated and used to determine if the engine has been driven within conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not reach regulating temperature of the thermostat, diagnostics that use the engine coolant temperature as enabling criteria may not run when expected.
If the coolant temperature does not reach the specified value within the established time parameters, the PCM determines that a malfunction exists and a DTC is stored.
Item | Detecting Condition | Possible cause | ||
DTC Strategy | ● Time(Tfbi) from engine starting to the reaching engine coolant temp. of F/B on | ● Poor connection ● Improper coolant level ● Resistance of wire in ECT sensor circuit ● Faulty thermostat ● Faulty ECTS | ||
Case 1 | Enable Conditions | ● AFS voltage ≥ 1.75V | ||
Threshold value | ● Tfbi | > 300sec @-7℃ | ||
> 120sec @10℃ | ||||
> 60sec @80℃ | ||||
Case 2 | Enable Conditions | ● AFS voltage < 1.75V | ||
Threshold value | ● Tfbi | > 300sec @-7℃ | ||
> 120sec @10℃ | ||||
> 60sec @80℃ | ||||
Diagnosis Time | ● 300 sec | |||
Temperature(℃/℉) | -33/-22 | -20/-4 | 0/32 | 20/68 | 40/140 | 60/140 | 80/176 | 100/212 | 110/230 |
Resistance(kΩ) | 26.74 | 15.48 | 5.79 | 2.45 | 1.148 | 0.587 | 0.322 | 0.188 | 0.147 |
Voltage(V) | 4.39 | 4.17 | 3.48 | 2.56 | 1.68 | 1.04 | 0.63 | 0.39 | 0.31 |
