The fluid of the CVVT is the engine oil and its density changes according to the engine oil temperature. At this time the Oil Temperature Sensor (OTS) helps compensation against the temperature differences. The Oil Temperature Sensor measures the engine oil temperature before the engine oil comes into the Oil-flow Control Valve (OCV). According to the measured temperature, the Engine Control Module (PCM) compensates the oil-flow control valve operation time.
Checking output signals from oil temperture sensor every 15 sec. under detecting condition, if an signal is low for more than 12.5 sec., PCM sets P0197. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● Signal low | ● Poor connection ● Short to ground in harness ● Oil temp.sensor ● PCM |
Enable Conditions | Case 1 | ● Engine running state >60 sec ● Coolant temperature < 110 °C(230°F) |
Case 2 | ● Engine running state >90 sec. | |
Threshold value | ● Oil temperature sensor’s signal< 0.1V | |
Diagnosis Time | ● Continuous (More than 12.5 sec.failure for every 15 sec.test) | |
MIL On Condition | ● 2 Driving Cycles |
Temperature(°C/°F) | Resistance(kΩ) |
-20°C/ -4°F | 16.52kΩ |
20°C/ 68°F | 2.45kΩ |
80°C/ 176°F | 0.29kΩ |