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.
The purpose of this diagnosis is to detect a stuck oil temperature signal or implausibly low ,high signal. For the stuck signal detection, the ECM checks whether after a variation of the calculated oil temperature also a variation of the measured oil temperature is detected and sets DTC P0196 if the variation of the measured oil temperature is lower than the threshold.
For the implausibly high, low signal detection, the ECM compares measured engine oil temperature with calculated oil temperature or coolant temperature and sets DTC P0196 when one of following conditions is met.
1) Measured oil temperature is implausibly low when calculated oil temperature is high.
2) Measured oil temperature is implausibly high when coolant is low without any relevant failure.
3) Measured oil temp.< threshold but calculated oil temp. >threshold
Item | Detecting Condition | Possible Cause | |
DTC Strategy | Case1) | ● Sensor signal implausible Low | ● Contact resistance in connectors ● Faulty OTS |
Case2) | ● Sensor signal implausible High | ||
Case3) | ● Sensor signal Stuck | ||
Enable Conditions | Case1) | ● Engine Oil temp. model>70℃(158℉) ● Engine coolant temperature at start <53℃(127.4℉) ● No relevant failure ● 6 < Battery voltage | |
Case2) | ● Engine coolant temperature < 70℃(158℉) ● No relevant failure ● 6 < Battery voltage | ||
Case3) | ● Minimum Oil Temperature model increase >50-100℃(122-212℉) depending on ECT at engine start ● Modeled coolant temp. or measured coolant temp.> 85°C(185°F) ● Engine coolant temperature at start < 40℃(104℉) ● No relevant failure ● 6 < Battery voltage | ||
Threshold Value | Case1) | ● Measured oil temperature < 20℃(68℉) | |
Case2) | ● Measured oil temperature > 100℃(212℉) | ||
Case3) | ● Measured oil temperature increase < 17~35℃(30~63℉)(Threshold depends on Coolant temperature at start) | ||
Diagnostic Time | Case1) | ● 15 seconds | |
Case2) | ● 15 seconds | ||
Case3) | ● 10-30 min. (depends on Engine Coolant Temp. and driving condition at start) | ||
Mil On Condition | ● 2 Driving Cycles | ||
Temp.(°C) | Temp.(°F) | OTS Resistance(kΩ) | Temp.(°C) | Temp.(°F) | OTS Resistance(kΩ) |
-20 | -4 | Approx. 14.1~16.9 | 40 | 104 | Approx. 1.1~1.2 |
0 | 32 | Approx. 6 | 60 | 140 | Approx. 0.5~0.6 |
20 | 68 | Approx. 2.3~2.6 | 80 | 176 | Approx. 0.3 |
