Range Rover P38
19
FUEL SYSTEM
NEW RANGE ROVER
20
DESCRIPTION AND OPERATION
Crankshaft position (CKP) sensor - (up to 99MY)
The crankshaft position sensor is the most important
sensor on the engine. It is located in the left hand side
of the flywheel housing and uses a different thickness
of spacer for manual and automatic gearboxes. The
signal it produces informs the ECM:
- the engine is turning
- how fast the engine is turning
- which stage the engine is at in the cycle
As there is no default strategy, failure of the CKP
sensor will result in the engine failing to start. The fault
is indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.
The output signal from the CKP sensor is obtained
from the magnetic path being made and broken as the
reluctor ring teeth pass the sensor tip. The reluctor
ring has 35 teeth and one missing tooth spaced at
10
°
intervals. The missing tooth is positioned at
20
°
after TDC.
Fault codes:
•
P0335 -Crankshaft sensor circuit fault - no signal
•
P0336 -Crankshaft sensor generating poor
quality signal
Camshaft position (CMP) sensor - (up to 99MY)
The camshaft sensor is located in the engine front
cover, between the belt pulleys. It is a Hall Effect
device which produces four pulses for every two
revolutions of the engine. The signal is used for two
purposes, injector timing corrections for fully
sequential fuelling and active knock control. The CMP
sensor signal pulses are generated from four gaps on
the cam wheel, one gap is smaller than the other
three, consequently one of the pulses is longer than
the others.
If the camshaft sensor fails, default operation is to
continue normal ignition timing. The fuel injectors will
be actuated sequentially, timing the injection with
respect to top dead centre. Injection will either be
correct or one revolution out of synchronisation. The
fault is not easily detected by the driver. The fault is
indicated by illumination of the malfunction indicator
light (MIL) on North American specification vehicles.
Fault codes:
•
P0340 - Camshaft sensor circuit fault or signal
timing different from crankshaft sensor signal.
NOTE: It is physically possible to
interchange the camshaft gear wheel fitted
to pre-99MY and post-99MY vehicles.
However, because the GEMS and Motronic
systems are incompatible, an incorrect camshaft
signal will be received by the ECM and a P0340
fault code will result.
