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(ECM) compensates the oil-flow control valve operation time.
Checking the oil temperture , coolant temperature and intake air temperature every 25 sec. under detecting condition, if the difference in temperature at start-up exceeds threshold value, ECM sets P0196. MIL(Malfunction Indicatin Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible Cause | |
DTC Strategy |
•
Determines if the oil temperature value is rational, compared to coolant and intake air temperature. | 1. Faulty OTS | |
Enable Conditions | Case 1 |
•
Engine run time after startup < 30 sec
•
Soak period required > 300 min | |
Case 2 |
•
Minimum engine run time > 800 sec | ||
Threshold value | Case 1 |
•
The difference in temperature between oil and coolant temperatures at startup. > 35℃(63°F) | |
Case 2 |
•
The difference in temperature between oil temperature and intake air temperature at startup > 35℃(63°F) | ||
Diagnosis Time |
•
Continous (More than 800 sec.) | ||
MIL On Condition |
•
NO MIL ON(DTC only) | ||
Temperature(℃/℉) | Resistance(kΩ) |
-40℃ | 52.15㏀ |
-20℃ | 16.52㏀ |
0℃ | 6.0㏀ |
20℃ | 2.45㏀ |
40℃ | 1.11㏀ |
60℃ | 0.54㏀ |
80℃ | 0.29㏀ |
Fig.1) Normal waveform of EOTS at 88.5℃.(191℉)
Fig.2) Normal data of IATS & ECTS & EOTS(51℉) at ig on.
Fig.3) Normal data of IATS & ECTS & EOTS(191℉) after warming up.
