LR3/Disco 3
The Engine Coolant Temperature sensor (ECT) is a Negative Temperature Coefficient (NTC) type sensor. As coolant
temperature rises the resistance of the sensor falls.
The sensor is located at the front of the engine behind and below the throttle body.
Should the sensor fail the ECM use the oil temperature sensor signal as a backup coolant temperature signal.
ENGINE OIL TEMPERATURE SENSOR
Oil temperature is monitored through a level sensor mounted in the engine sump.
The sensor operates in the range -40 TO 150 degrees Celsius.
MASS AIR FLOW /INLET AIR TEMPERATURE SENSOR (MAF/IAT)
The MAF and IAT sensor is located in the air duct between the air filter and throttle body.
The air mass flow is determined by the cooling effect of inlet air passing over a “hot film” element contained within the
device. The higher the air flow the greater the cooling effect and the lower the electrical resistance of the element. The
signal from the device is then calculated by the ECM to determine the Air Mass Flow into the engine.
The measured air mass flow is used in determining the fuel quantity to be injected in order to maintain the stichometric
air/fuel mixture required for correct operation of the engine and exhaust catalysts. Should the device fail there is a
software backup strategy that will be evoked once a fault has been diagnosed.
