Range Rover P38
19
FUEL SYSTEM
NEW RANGE ROVER
60
DESCRIPTION AND OPERATION
Secondary air injection system (NAS only from
2000MY)
Refer to EMISSION CONTROL section for description
of the secondary air injection system components.
Inertia Fuel Shut-off (IFS) Switch
The inertia switch isolates the power supply to the fuel
pump in the event of sudden deceleration, as
encountered during an accident. The inertia switch is
located in the right hand side footwell behind an
access flap. It is reset by depressing the central
plunger at the top of the switch.
E-box Cooling Fan control - from 99MY only
The cooling fan is utilised to provide a cool
temperature environment for the Bosch Motronic 5.2.1
ECM in the under bonnet mounted E-box. The fan
provides cabin air into the E-box and operation is
controlled by the ECM. The ECM contains an internal
temperature sensor which it uses to determine when
cooling fan operation is necessary.
Spark plugs - from 99MY
The spark plugs are platinum tipped on both centre
and earth electrodes to provide a long maintenance
free life and exceptional cold starting performance.
CAUTION: Do not clean the spark plugs or
attempt to reset the spark plug gap.
CAUTION: If the wrong specification spark
plugs are used, the misfire detection
system is likely to malfunction and
corresponding error codes will be stored in the
ECM diagnostic memory. Only use the
recommended spark plugs.
In the event of a spark plug failure, a misfire on a
specific cylinder may be observed.
A spark plug failure may occur for the following
reasons:
•
Connector or wiring fault
•
Faulty plug (e.g. wrong gap, damaged
electrodes etc.)
•
Incorrect spark plugs fitted
•
Breakdown of high tension lead causing tracking
to chassis earth
High tension (ht) leads
The ht leads are routed from the ignition coils at the
back of the engine to four spark plugs on each bank of
the engine block.
An ht lead failure will result in a misfire condition on a
specific cylinder.
An ht lead failure may occur for the following reasons:
•
Connector / wiring fault
•
Faulty lead causing spark tracking to chassis
earth
•
Damage to ht lead during gearbox removal
Electronic Automatic Gearbox Interface - from
99MY
The ECM communicates with the EAT ECU via a
Controller Area Network (CAN). This is used for the
gearshift torque interface and as a means for
transmitting OBD information between the two control
units. The EAT ECU passes OBD data and requests
to the ECM which controls the storage of diagnostics
data and MIL activation. Unlike the GEMS ECM, the
Bosch M5.2.1 does not store gearbox faults. The MIL
activation request can be checked with Testbook.
The CAN network is a high speed serial interface
operating at 500 k-baud. The system is a differential
bus using a twisted pair. If either or both wires of the
twisted pair CAN bus is open or short circuited, a CAN
time out fault will occur and the EAT ECU defaults to
third gear.
See AUTOMATIC GEARBOX, Description and
operation.