Range Rover P38
19
FUEL SYSTEM
NEW RANGE ROVER
22
DESCRIPTION AND OPERATION
Engine Coolant Temperature (ECT) sensor - (up to
99MY)
The sensor is located at the top front of the engine, to
the right of the alternator and in front of the plenum
chamber.
The sensor comprises a temperature dependant
resistive metal strip. The resistance of the strip varies
considerably with coolant temperature, i.e. from 28K
ohms at - 30
°
C to 90 ohms at 130
°
C. At 85
°
C the
resistance is 300 ohms. The ECT sensor signal is vital
to engine running, as the correct fuelling is dependant
upon engine temperature i.e. richer mixture at low
temperatures.
If the sensor is disconnected or failure occurs, a
default value will be supplied to the system. The initial
default value selected will be based on the value of
the air intake temperature. This will increase to a
nominal warmed up value over a given time,
programmed for each default value. The fault may not
be evident to the driver, there may be a hot restart
problem. The fault is indicated by illumination of the
malfunction indicator light (MIL) on North American
specification vehicles.
Fault codes:
•
P0116 - Coolant temperature sensor - falling
temperature fault
•
P0117 - Coolant temperature sensor circuit low
range fault
•
P0118 - Coolant temperature sensor circuit high
range fault
•
P0125 - Coolant temperature sensor - no
warm-up fault
Engine Fuel Temperature (EFT) sensor - (up to
99MY)
The EFT sensor is located on the fuel rail by cylinders
3 and 5. The sensor measures the temperature of the
rail rather than the fuel. The resistance varies with
changes in temperature. The signal is used to
increase the injection pulse time when undergoing hot
restarts. When the fuel is hot, vapourisation can occur
in the fuel rail and bubbles form in the injectors.
Increasing the pulse time helps flush the fuel vapour
away. An EFT sensor fault may not be evident to the
driver, there may be a hot restart problem. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.
Fault codes:
•
P0181 - Fuel temperature sensor fault - reading
invalid compared with water temperature
•
P0182 - Fuel temperature sensor circuit low
range fault
•
P0183 - Fuel temperature sensor circuit high
range fault