The purpose of this diagnosis is to detect a stuck intake air temperature signal. The diagnostic function checks whether after a variation of the calculated intake air temperature also a variation of the measured intake air temperature is detected. PCM/ECM 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/ECM is greater than threshold.
Item | Detecting Condition | Possible Cause | |
DTC Strategy |
•
Plausibility check | 1. Poor connection or damaged harness 2. Faulty IAT sensor | |
Enable Conditions | Case1 |
•
Engine running
•
Battery voltage
•
Failure not detected for DTC
•
Engine Coolant Temperature
•
Coolant temperature at engine start - coolant temperature at engine at pervious driving cycle
•
Cumulative time for IAT signal increase check( low load driving condition :air flow ＜ 20kg/h and vehicle speed ＜ 12.4 mile/hour)
•
Cumulative time for IAT signal decrease check(high load driving condition : air flow 40kg/h and vehicle speed ＞ 24.8 mile/hour | |
Case2 |
•
Ignition "ON"
•
Battery voltage ≥ 6V
•
No Intake Air Temp.(IAT) sensor electrical error | ||
Threshold Value | Case1 |
•
Intake air temperature signal vatiation since Engine start ＜ Threshold versus Air temperature at start(35.6F … 104F)
•
Low start intake air temperature:failure if IAT variation ＜ 34.7F
•
Middle start intake air temperature:failure if IAT variation ＜ 34.7F
•
High start intake air temperature:failure if IAT variation ＜ 68F | |
Case2 |
•
IAT - IAT moving mean value ＞ 46.4F | ||
Diagnostic Time | Case1 |
•
Immediate | |
Case2 |
•
0.5 sec. | ||
MIL On Condition |
•
2 Drive Cycles | ||
