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.
The purpose of this diagnosis is to detect a stuck oil temperature signal or implausibly low ,high signal. For the stuck signal detection, the PCM 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 PCM compares measured engine oil temperature with calculated oil temperature or coolant temperature and sets DTC P0196 when one of following conditions is met.
Measured oil temperature is implausibly low when calculated oil temperature is high.
Measured oil temperature is implausibly high when coolant is low without any relevant failure.
Measured oil temp. < threshold but calculated oil temp. > threshold.
Item
Detecting Condition
Possible Cause
DTC
Strategy
case1
Sensor signal Stuck
Poor connection or damaged harness
Faulty OTS
case2
Signal plausability
Enable
Conditions
Engine coolant temperature at start < 40?(104?)
No relevant failure
6 < Battery voltage<16V
6 < Battery voltage < 16V
Threshold Value
Measured oil temperature increase < 10~35?(50~63?)(Threshold depends on Coolant temperature at start)
Measured oil temperature < 20?(68?)
Measured oil temperature > 100?(212?)
Diagnostic Time
10-30 min. (depends on Engine Coolant Temp. and driving condition at start)
15 seconds.
Mil On Condition
2 Driving Cycles
Temp.(?)
OTS Resistance(?)
-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
Engine Oil Temp. Sensor : Approx. 96 ? after warm up.(at IG ON)