Freelander System Description and Operation
ENGINE MANAGEMENT SYSTEM - SIEMENS
DESCRIPTION AND OPERATION 18-4-21
IAT Sensor
1 Sensor
2 Housing
The IAT sensor provides a signal that enables the ECM to adjust ignition timing and fuelling quantity according to the
intake air temperature, thus ensuring optimum performance, driveability and emissions.
The IAT sensor is a Negative Temperature Coefficient (NTC) thermistor located in a plastic housing installed in the
intake duct between the MAF sensor and the throttle body. The sensor is a push fit in the housing and sealed by an
'O' ring. A clip is integrated into the sensor to secure it in the housing.
If the input from the IAT sensor fails, the vehicle will continue to run. The ECM will substitute a default value using the
information from the speed/load map to run the engine, but adaptive fuelling will be disabled.
