The purpose of this diagnosis is to detect intake air temperature signal stuck. PCM sets DTC P0111 when the variation of measured intake air temperature from engine start is smaller than threshold while variation of calculated intake air temperature by PCM is greater than threshold.
Item | Detecting Condition | Possible Cause | |
DTC Strategy |
•
Plausibility Check | 1. Poor Connector Connection 2. Defected IAT Sensor | |
Enable Condition | Case 1 |
•
Engine speed higher than 640 to 960 RPM depending on start ECT
•
Battery voltage higher than 6 V and lower than 16 V
•
Engine Coolant Temperature(ECT) higher than 165.2℉(74℃)
•
Deviation of ECT at engine start and ECT at previous engine stop higher than 41.45℉(5.25℃)
•
Cumulative time for AIT signal increase for more than 200 sec. (at low load driving condition : mass air flow less than 5.5g/sec(20kg/h) & vehicle speed lower than 12.4 mph(20 km/h))
•
Cumulative time for AIT signal decrease for more than 160 sec. (at low high driving condition : mass air flow less than 11.1g/sec(40kg/h) & vehicle speed lower than 24.8 mph(40 km/h))
•
No relevant DTC present | |
Case 2 |
•
Battery voltage higher than 6 V and lower than 16 V
•
No relevant DTC present | ||
Threshold Value | Case 1 |
•
Intake air temperature signal variation since engine start :
–
Low IAT at start : failure if IAT variation less than 34.7℉(1.5℃)
–
Middle IAT at start : failure if IAT variation less than 34.7℉(1.5℃)
–
High IAT at start : failure if IAT variation less than 68℉(20℃) | |
Case 2 |
•
Deviation of IAT and IAT moving mean value more than 46.85℉(8.25℃) (Noise Signal) | ||
Diagnostic Time | Case 1 |
•
Immediately | |
Case 2 |
•
5 sec. | ||
MIL ON Condition |
•
2 Driving Cycle | ||
