Land Rover LR3/Discovery 3 Service & Repair Manuals

 
Oil temperature is monitored through a temperature sensor mounted in the oil system. This component is a NTC (negative
temperature coefficient) . The sensor is mounted next to the oil pressure sensor at the front of the engine and locates into 
the oil filter bracket.  
 

FUEL RAIL TEMPERATURE SENSOR 

 
The fuel rail temperature sensor measures the temperature of the fuel in the fuel rail. This input is then used to deliver the 
correct quantity of fuel to the engine. Operating Range -40 Degrees Celsius to 150 Degrees Celsius. The fuel rail 
temperature sensor is fitted on the rear of the right hand bank (bank A) fuel rail. 
 

MASS AIR FLOW/INLET AIR TEMPERATURE SENSOR (MAF/IAT) 

 
The air flow meter is located in the clean air duct immediately after the air filter box. 
 
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 “hot film” 
element. The ECM then uses this signal from the Mass Air Flow meter to calculate the air mass flowing 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. 
 
The following symptoms may be observed if the sensor fails: 
 

During driving the engine RPM might dip, before recovering.