Intake Air Temperature Sensor(IATS) is NTC thermistor. Installed inside of both MAFS and BPS, it senses intake air temperature.
In case of EURO-4 diesel engine, IATS is installed in front of turbocharger(inside of MAFS) and behind it(inside of BPS). Comparing air temperature from both sensors(one is intake air temperature, the other is air temperature passing through turbo charger), more accurate sensing of intake air temperature is possible.
With intake air temperature signal, ECM performs EGR control correction and fuel injection quantity correction.(MAFS is needed for EGR FEED BACK control in electronically controlled diesel engine. The calculation of air density at certain temperture is required to perform EGR FEED BACK control correctly.)
P0098 is set when the voltage above 4880mV - maximum output voltage of IATS(integrated with BPS) - is detected for more than 5.67 sec.. This code is due to 1) open or 2) short to ground or 3) short to battery in IATS signal circuit.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage monitoring
IATS circuit
IATS component
Enable Conditions
IG KEY "ON"
Threshold Value
Output signal above maximum value( above 4880mV )
Diagnostic Time
5.67 sec.
Fail Safe
Fuel cut
NO
Intake Air Temperature sensor is fixed at 50?.
EGR Off
Fuel Limit
Check Lamp
Temp.
'- 40?
'-20?
0?
20?
40?
60?
80?
Resistance
35.14~43.76K?
12.66~15.12K?
5.12~5.89K?
2.29~2.55K?
1.10~1.24K?
0.57~0.65K?
0.31~0.37K?