2002 LAND ROVER DISCOVERY stop start

MAINTENANCE
PROCEDURES 10-17
Automatic gearbox
WARNING: Avoid excessive skin contact with
mineral oil. Mineral oils remove the natural fats
from the skin, leading to dryness, irritation and
dermatitis.
Replace oil filter
1.Replace oil filter.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, REPAIRS, Filter - oil.
Replace oil
1. Ensure that gearbox is cool. Apply
handbrake and securely chock front and rear
wheels.
2.Place a suitable container beneath gearbox.
3.Clean area around oil filler/level and drain
plugs.
4.Remove oil drain plug, remove and discard
sealing washer.
5.Allow oil to drain.
6.Fit new sealing washer to oil drain plug.
7.Fit automatic gearbox drain plug and tighten to
15 Nm (11 lbf.ft).
8.Remove oil filler/level plug, remove and discard
sealing washer.9.Fill gearbox with recommended oil to bottom of
oil level/filler plug hole.

+ CAPACITIES, FLUIDS AND
LUBRICANTS, Lubrication.
10.Select 'P' (Park).
11.Ensure handbrake is applied.
12.Start engine and allow it to idle.
13.Apply footbrake.
14.Move selector lever through all gear positions,
while continuing to fill the gearbox. Select 'P'
(Park).
15.With engine idling, continue filling gearbox until
a 2 mm bead of oil runs from oil filler/level plug
hole.
16.Fit new sealing washer to automatic gearbox
filler/level plug, fit plug and tighten to 30 Nm (22
l b f . f t ) .
17.Stop engine.
18.Remove all traces of oil from gearbox casing.

ENGINE - TD5
REPAIRS 12-1-57
Filter - oil
$% 12.60.04
Remove
1.Remove 3 bolts and remove engine acoustic
cover.
2.Remove 3 bolts and remove exhaust manifold
heat shield.
3.Clean area around filter head and place a
container beneath engine.
4.Using a strap wrench, unscrew and discard
filter. Refit
1.Clean mating face of filter head.
2.Lubricate sealing ring of new filter with clean
engine oil.
3.Fit filter and tighten by hand until it seats then
tighten a further three-quarters of a turn.
4.Start and run engine to check for leaks.
5.Stop engine, wait a few minutes, then check oil
level.
6.Top up engine oil.

+ MAINTENANCE, PROCEDURES,
Engine oil - diesel engine.
7.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolts
to 25 Nm (18 lbf.ft).
8.Fit engine acoustic cover and secure with
fixings.

ENGINE - V8
12-2-34 REPAIRS
4.Ensure ring gear is correctly seated around the
complete circumference of flywheel and allow
to cool.
5.Fit flywheel.

+ ENGINE - V8, REPAIRS, Flywheel.
Filter - oil
$% 12.60.04
Remove
1.Clean area around filter head and place a
container beneath engine.
2.Using a strap wrench, unscrew and discard
filter.
Refit
1.Clean mating face of filter head.
2.Lubricate sealing ring of new filter with clean
engine oil.
3.Fit filter and tighten by hand until it seats then
tighten a further half turn.
4.Start and run engine to check for leaks.
5.Stop engine, wait a few minutes, then check oil
level.
6.Top up engine oil.

EMISSION CONTROL - V8
17-2-26 DESCRIPTION AND OPERATION
Secondary air injection system
The secondary air injection (SAI) system comprises the following components:
lSecondary air injection pump
lSAI vacuum solenoid valve
lSAI control valves (2 off, 1 for each bank of cylinders)
lSAI pump relay
lVacuum reservoir
lVacuum harness and pipes
The secondary air injection system is used to limit the emission of carbon monoxide (CO) and hydrocarbons (HCs)
that are prevalent in the exhaust during cold starting of a spark ignition engine. The concentration of hydrocarbons
experienced during cold starting at low temperatures are particularly high until the engine and catalytic converter
reach normal operating temperature. The lower the cold start temperature, the greater the prevalence of
hydrocarbons emitted from the engine.
There are several reasons for the increase of HC emissions at low cold start temperatures, including the tendency for
fuel to be deposited on the cylinder walls, which is then displaced during the piston cycle and expunged during the
exhaust stroke. As the engine warms up through operation, the cylinder walls no longer retain a film of fuel and most
of the hydrocarbons will be burnt off during the combustion process.
The SAI pump is used to provide a supply of air into the exhaust ports in the cylinder head, onto the back of the
exhaust valves, during the cold start period. The hot unburnt fuel particles leaving the combustion chamber mix with
the air injected into the exhaust ports and immediately combust. This subsequent combustion of the unburnt and
partially burnt CO and HC particles help to reduce the emission of these pollutants from the exhaust system. The
additional heat generated in the exhaust manifold also provides rapid heating of the exhaust system catalytic
converters. The additional oxygen which is delivered to the catalytic converters also generate an exothermic reaction
which causes the catalytic converters to 'light off' quickly.
The catalytic converters only start to provide effective treatment of emission pollutants when they reach an operating
temperature of approximately 250
°C (482°F) and need to be between temperatures of 400°C (752°F) and 800°C
(1472
°F) for optimum efficiency. Consequently, the heat produced by the secondary air injection “afterburning”,
reduces the time delay before the catalysts reach an efficient operating temperature.
The engine control module (ECM) checks the engine coolant temperature when the engine is started, and if it is below
60º C (131
°F), the SAI pump is started. Secondary air injection will remain operational for a period controlled by the
ECM (76 seconds for NAS vehicles, 64 seconds for EU-3 vehicles). The SAI pump operation can be cut short due to
excessive engine speed or load.
Air from the SAI pump is supplied to the SAI control valves via pipework and an intermediate T-piece which splits the
air flow evenly to each bank.
At the same time the secondary air pump is started, the ECM operates a SAI vacuum solenoid valve, which opens to
allow vacuum from the reservoir to be applied to the vacuum operated SAI control valves on each side of the engine.
When the vacuum is applied to the SAI control valves, they open simultaneously to allow the air from the SAI pump
through to the exhaust ports. Secondary air is injected into the inner most exhaust ports on each bank.
When the ECM breaks the ground circuit to de-energise the SAI vacuum solenoid valve, the vacuum supply to the
SAI control valves is cut off and the valves close to prevent further air being injected into the exhaust manifold. At the
same time as the SAI vacuum solenoid valve is closed, the ECM opens the ground circuit to the SAI pump relay, to
stop the SAI pump.
A vacuum reservoir is included in the vacuum line between the intake manifold and the SAI vacuum solenoid valve.
This prevents changes in vacuum pressure from the intake manifold being passed on to cause fluctuations of the
secondary air injection solenoid valve. The vacuum reservoir contains a one way valve and ensures a constant
vacuum is available for the SAI vacuum solenoid valve operation. This is particularly important when the vehicle is at
high altitude.

EMISSION CONTROL - V8
17-2-42 DESCRIPTION AND OPERATION
Secondary air injection system
When the engine is started, the engine control module checks the engine coolant temperature and if it is below 55°
C, the ECM grounds the electrical connection to the coil of the secondary air injection (SAI) pump relay.
A 12V battery supply is fed to the inertia switch via fuse 13 in the engine compartment fusebox. When the inertia
switch contacts are closed, the feed passes through the switch and is connected to the coil of the Main relay. An earth
connection from the Main relay coil is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the Main relay.
The Main and Secondary Air Injection (SAI) pump relays are located in the engine compartment fusebox. When the
contacts of the Main relay are closed, a 12V battery supply is fed to the coil of the SAI pump relay. An earth connection
from the coil of the SAI pump relay is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the SAI pump relay to supply 12V to the SAI pump via fusible link 2 in the engine
compartment fusebox. The SAI pump starts to operate, and will continue to do so until the ECM switches off the earth
connection to the coil of the SAI pump relay.
The SAI pump remains operational for a period determined by the ECM and depends on the starting temperature of
the engine, or for a maximum operation period determined by the ECM if the target engine coolant temperature has
not been reached in the usual time.
When the contacts of the main relay are closed, a 12V battery supply is fed to the SAI solenoid valve via Fuse 2 in
the engine compartment fusebox.
The ECM grounds the electrical connection to the SAI vacuum solenoid valve at the same time as it switches on the
SAI pump motor. When the SAI vacuum solenoid valve is energised, a vacuum is provided to the operation control
ports on both of the vacuum operated SAI control valves at the exhaust manifolds. The control vacuum is sourced
from the intake manifold depression and routed to the SAI control valves via a vacuum reservoir and the SAI vacuum
solenoid valve.
The vacuum reservoir is included in the vacuum supply circuit to prevent vacuum fluctuations caused by changes in
the intake manifold depression affecting the operation of the SAI control valves.
When a vacuum is applied to the control ports of the SAI control valves, the valves open to allow pressurised air from
the SAI pump to pass through to the exhaust ports in the cylinder heads for combustion.
When the ECM has determined that the SAI pump has operated for the desired duration, it switches off the earth paths
to the SAI pump relay and the SAI vacuum solenoid valve. With the SAI vacuum solenoid valve de-energised, the
valve closes, cutting off the vacuum supply to the SAI control valves. The SAI control valves close immediately and
completely to prevent any further pressurised air from the SAI pump entering the exhaust manifolds.
The engine coolant temperature sensor incurs a time lag in respect of detecting a change in temperature and the SAI
pump automatically enters a 'soak period' between operations to prevent the SAI pump overheating. The ECM also
compares the switch off and start up temperatures, to determine whether it is necessary to operate the SAI pump.
This prevents the pump running repeatedly and overheating on repeat starts.
Other factors which may prevent or stop SAI pump operation include the prevailing engine speed / load conditions.

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-17
The CKP sensor can fail the following ways or supply incorrect signal:
lSensor assembly loose.
lIncorrect spacer fitted.
lSensor open circuit.
lSensor short circuit.
lIncorrect fitting and integrity of the sensor.
lWater ingress.
In the event of a CKP sensor signal failure any of the following symptoms may be observed:
lEngine cranks but fails to start.
lMIL remains on at all times.
lEngine misfires (CKP sensor incorrectly fitted).
lEngine runs roughly or even stalls (CKP sensor incorrectly fitted).
CKP does not have any backup strategy and if it fails the engine will stop running and fail to start.

ENGINE MANAGEMENT SYSTEM - TD5
18-1-24 DESCRIPTION AND OPERATION
Fuel pump relay
The fuel pump relay is located in the engine compartment fuse box. It switches on the fuel pump to draw fuel from
the fuel tank to the electronic unit injectors (EUI).
Input/Output
The fuel pump relay is a 4 pin normally open relay. Voltage input to the fuel pump relay comes from the main relay
switching contacts. When the main relay is energised the switching contacts close and the fuel pump relay windings
are supplied a voltage. The ECM provides the earth for the relay windings to close the relay contacts and operate the
fuel lift pump. The fuel pump relay switching contacts are supplied voltage via fuse 10 located in the engine
compartment fuse box. Output from these switching contacts is supplied directly to the fuel pump. When the ECM
interrupts the earth the return spring in the relay pulls the contacts apart and the fuel lift pump stops operating. The
earth path is via pin 5 of ECM connector C0658.
The fuel pump relay can fail in the following ways:
lRelay open circuit.
lShort circuit to vehicle supply.
lShort circuit to vehicle earth.
lBroken return spring.
In the event of a fuel pump relay failure any of the following symptoms may be observed:
lEngine will crank but not start.
lIf the engine is running it will stop.
The MIL will not illuminate in a fuel pump relay failure.

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-25
Main relay
The main relay is located in the engine compartment fuse box and supplies battery voltage to the following:
lECM.
lMAF.
lFuel pump relay.
lCruise control master switch.
lCruise control RES switch.
lCruise control SET+ switch.
It is a 4 pin normally open relay and must be energised to provide voltage to the ECM.
Input/Output
The earth path for the main relay is via a transistor within the ECM. When the earth path is completed, the main relay
energises to supply battery voltage to the ECM. Interrupting this earth path de-energises the main relay, preventing
battery voltage reaching the ECM.
Input to the main relay is via pin 1 of connector C0632, located at the engine compartment fuse box. Output from the
main relay is via fuse 1 to the ECM connector C0658 pins 3, 22 and 27. The earth path is via pin 21 of ECM connector
C0658.
The main relay can fail in the following ways:
lRelay open circuit.
lShort circuit to vehicle supply.
lShort circuit to vehicle earth.
lBroken return spring.
In the event of a main relay failure any of the following symptoms may be observed:
lEngine will crank but not start.
lIf the engine is running it will stop.
For the ECM start up to take place the ignition 'on' (position II) voltage must be greater than 6.0 volts.