1999 LAND ROVER DEFENDER battery

ENGINE
27
REPAIR Refit
9.Clean sump and mating faces.
10.Apply a bead of sealant, Part No. STC 3254 to
joint faces of timing chain cover and crankshaft
rear oil seal.
11.Position new sump gasket.
CAUTION: Gasket must be fitted dry.
12.Position sump, fit bolts ensuring they are in their
correct fitted position, lightly tighten bolts.
13.Fit bolts securing sump to gearbox bell housing
and tighten to15 Nm (11 lbf.ft).
14.Using sequence shown, tighten sump bolts to25
Nm (18 lbf.ft).
15.Tighten sump to gearbox bell housing bolts to50
Nm (37 lbf ft).
16.Fit new gasket to centrifuge drain pipe and
tighten bolts to10 Nm (7 lbf.ft).
17.Fit exhaust front pipe.See MANIFOLD AND
EXHAUST SYSTEM, Repair.
18.Refill engine with oil.
19.Reconnect battery negative lead.
20.Refit battery cover.
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EMISSION CONTROL
1
REPAIR VALVE - EGR - NON EU3 MODELS
Service repair no - 17.45.01
Remove
1.Disconnect battery negative lead.
2.Remove 3 bolts and remove engine acoustic
cover.
3.Remove cooling fan.See COOLING SYSTEM,
Repair.
4.Remove battery cover.
5.Disconnect battery negative lead.
6.Disconnect vacuum hose from EGR valve
7.Loosen clip screw and release air intake from
EGR valve.
8.Remove 4 bolts, release EGR valve from inlet
manifold and discard gasket.
9.Remove 2 bolts and release EGR valve clip from
cylinder head.
10.Remove and discard 2 Allen screws securing
EGR valve pipe to exhaust manifold.
11.Remove EGR valve assembly.
12.Remove clip and remove pipe from EGR valve.Refit
13.Clean EGR valve and mating face on pipe.
14.Position pipe to EGR valve, fit retaining clip and
finger tighten bolt.
15.Clean inlet manifold face.
16.Position EGR valve to inlet manifold using new
gasket and tighten bolts to10 Nm (7lbf.ft).
17.Position air intake hose and tighten clip screw.
18.Position EGR pipe bracket, fit bolts and finger
tighten.
19.Position EGR valve pipe to exhaust manifold and
finger tighten allen screws
20.Tighten EGR valve clip to5 Nm (3 lbf.ft).
21.Tighten EGR pipe bracket bolts to10 Nm (7
lbf.ft).
22.Tighten 2 Allen screws to10 Nm (7 lbf.ft).
23.Connect vacuum hose to EGR valve.
24.Fit cooling fan.See COOLING SYSTEM,
Repair.
25.Fit engine acoustic cover.
26.Reconnect battery negative lead.
27.Fit battery cover.
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17EMISSION CONTROL
2
REPAIR VALVE - EGR - EU3 MODELS
Service repair no - 17.45.01
Remove
1.Release turnbuckles and remove battery cover.
2.Disconnect battery earth lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Remove cooling fan coupling.See COOLING
SYSTEM, Repair.
5.Disconnect vacuum hose(s) from EGR valve.
6.Loosen screw and disconnect air intake hose
from EGR valve.
7.Remove screw and remove clamp securing EGR
pipe to EGR valve.
8.Remove 4 bolts securing EGR valve, remove
valve and discard gasket.
9.Discard EGR pipe gasket.Refit
10.Clean EGR valve and mating faces.
11.Fit new gasket to EGR pipe.
12.Using new gasket, position EGR valve to inlet
manifold fit bolts and tighten to10 Nm (7 lbf.ft).
13.Fit EGR pipe clamp and tighten screw to6Nm
(4.4 lbf.ft).
14.Connect air intake hose to EGR valve and
tighten clip.
15.Connect vacuum hoses to EGR valve.
16.Fit cooling fan coupling.See COOLING
SYSTEM, Repair.
17.Fit engine acoustic cover and tighten bolts to10
Nm (7 lbf.ft).
18.Connect battery earth lead.
19.Fit battery cover and secure the fixings.
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ENGINE MANAGEMENT SYSTEM
7
DESCRIPTION AND OPERATION SENSOR - MASS AIR FLOW (MAF)
The MAF sensor is located in the intake system between the air filter housing and the turbocharger. The ECM
uses the information generated by the MAF sensor to control exhaust gas recirculation (EGR).
The MAF sensor works on the hot film principal. The MAF sensor has 2 sensing elements contained within a film.
One element is controlled at ambient temperature e.g. 25°C (77°F) while the other is heated to 200°C (360°F)
above this temperature e.g. 225°C (437°F). As air passes through the MAF sensor the hot film will be cooled.
The current required to keep the constant 200°C (360°F) difference provides a precise although non-linear signal
of the air drawn into the engine. The MAF sensor sends a voltage of between 0 and 5 volts to the ECM,
proportional to the mass of the incoming air. This calculation allows the ECM to set the EGR ratio for varying
operating conditions.
Inputs / Outputs
The MAF sensor receives battery voltage (C0149-3) via the ECM on a brown/orange wire. Signal output on a
slate/light green wire from the MAF sensor (C0149-2) to the ECM (C0158-11) is a variable voltage proportional to
the air drawn into the engine. The MAF sensor is provided an earth (C0149-1) via the ECM (C0158-20) on a
pink/black wire.
The MAF sensor can fail or supply an incorrect signal if one or more of the following occurs:
Sensor open circuit.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Contaminated sensor element.
Damaged sensor element.
Damaged wiring harness.
MAF sensor supplies incorrect signal (due to air leak or air inlet restriction).
In the event of a MAF sensor signal failure any of the following symptoms my be observed:
During driving, engine speed may dip before recovering.
Difficult starting.
Engine stalls after starting.
Delayed throttle response.
EGR inoperative.
Reduced engine performance.
MAF signal out of parameters.
In the event of a MAF sensor failure, the ECM will use a fixed default value from its memory.
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18ENGINE MANAGEMENT SYSTEM
18
DESCRIPTION AND OPERATION ELECTRONIC UNIT INJECTOR (EUI)
The EUI’s are located in the top of the engine inside the camshaft cover. There is one EUI per cylinder. They inject
finely atomised fuel directly into the combustion chamber. Each EUI has its own electrical connection, which is
linked to a common harness also located under the camshaft cover. Each of the EUI’s has its own 5 letter grading
code. This code is used so that greater EUI precision is achieved.
Using an injection timing map within its memory and information from the CKP sensor the ECM is able to
determine precise crankshaft angle. When the ECM determines the crankshaft speed and position it closes the
spill valve within the EUI. Fuel pressure rises inside the EUI to a predetermined limit of 1500 bar (22,000 lbf.in
2)on
pre EU3 models, and 1750 bar (25,500 lbf.in2) on EU3 models . At this limit the pintle lifts off its seat allowing the
fuel to inject into the combustion chamber. The ECM de-energises the spill valve to control the quantity of fuel
delivered. This causes a rapid pressure drop within the EUI which allows the EUI return spring to re-seat the
pintle, ending fuel delivery.
The electrical circuit that drives the EUI works in two stages depending on battery voltage. If battery voltage is
between 9 and 16 volts the EUI’s will provide normal engine performance. If however battery voltage falls to
between 6 and 9 volts on pre EU3 models, EUI operation is restricted to a limit of 2100 rev/min. On EU3 models,
EUI operation is restricted to idle. If the vehicle is fitted with a new ECM, the EUI grades for that specific vehicle
must be downloaded to the new ECM using TestBook. In the event of the engine failing to rev above 3000 rev/min
it is probable that the EUI grading has not been completed.
Input / Output
Input to the EUI takes the form of both mechanical and electrical signals. The mechanical input to the EUI is diesel
fuel via the fuel pump operating at approximately 4 to 5 bar (58 to 72 lbf.in
2). Each of the EUI’s is operated
mechanically by an overhead camshaft to enable injection pressures of up to 1500 bar (22,000 lbf.in2) on pre EU3
models, and 1750 bar (25,500 lbf.in2) on EU3 models, to be achieved. The ECM controls the EUI’s to ensure that
fuel delivery is precise and as intended.
The EUI’s earth paths are as follows:
EUI 1 (C0522-1) via the ECM (C0158-25) on a yellow wire.
EUI 2 (C0523-1) via the ECM (C0158-26) on a yellow/brown wire.
EUI 3 (C0524-1) via the ECM (C0158-27) on a yellow/blue wire.
EUI 4 (C0525-1) via the ECM (C0158-24) on a yellow/red wire.
EUI 5 (C0526-1) via the ECM (C0158-1) on a yellow/purple wire.
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ENGINE MANAGEMENT SYSTEM
21
DESCRIPTION AND OPERATION RELAY - FUEL PUMP
The fuel pump relay is located in the engine compartment fuse box. It switches on the fuel pump to draw fuel from
the tank to the electronic unit injectors (EUI).
Input / Output
The fuel pump relay is a 4 pin normally open relay. The fuel pump relay (C0730-4) is provided with a feed by the
main relay (C0063-78) via header 291 on a brown/orange wire. An earth path is provided for the fuel pump relay
(C0730-6) via the ECM (C658-5) on a blue/purple wire. This energises the fuel pump relay and allows a feed to be
provided to the fuel pump. When the ECM interrupts the earth, the relay is de-energised and the fuel pump stops
operating.
The fuel pump relay can fail in one or more of the following ways:
Relay open circuit.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Broken relay return spring.
In the event of a fuel pump relay failure any of the following symptoms may be observed:
Engine will crank but not start.
If the engine is running, it will stop.
RELAY - MAIN
The main relay is located in the engine compartment fuse box and supplies battery voltage to the following:
The ECM.
The MAF sensor.
Fuel pump relay.
Input / Output
The main relay is a 4 pin normally open relay, which must be energised to provide a voltage to the ECM. The main
relay (C0063-86) is provided with an earth path via a transistor within the ECM (C0658-21) on a blue/red wire.
When the earth path is completed, the relay is energised and supplies the ECM (C0658-3, C0658-22 & C0658-27)
with a feed on brown/orange wires via header 291.
The main relay can fail in the following ways:
Relay open circuit.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Broken relay return spring.
In the event of a main relay failure any of the following symptoms may be observed:
Engine will crank but not start.
If the engine is running, it will stop.
For the ECM start up to take place the ignition feed when the switch is in position’II’must be greater than 6.0
volts.
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18ENGINE MANAGEMENT SYSTEM
24
DESCRIPTION AND OPERATION GLOW PLUGS
The 4 glow plugs are located in the engine block on the inlet side, in cylinders 1 to 4. Cylinder 5 has no glow plug.
The glow plugs are a vital part of the engine starting strategy. The purpose of the glow plugs are:
Assist cold engine start.
Reduce exhaust emissions at low engine load/speed.
The main part of the glow plug is a tubular heating element that protrudes into the combustion chamber of the
engine.The heating element contains a spiral filament that is encased in magnesium oxide powder. At the tip of
the tubular heating element is the heater coil. Behind the heater coil and connected in series is a control coil. The
control coil regulates the heater coil to ensure that it does not overheat and cause a possible failure. The glow
plug circuit has its own control relay, located underneath the RH front seat.
Pre-heat is the length of time the glow plugs operate prior to engine cranking. The ECM controls the pre-heat time
of the glow plugs based on battery voltage and coolant temperature information via the glow plug relay.
Post-heat is the length of time the glow plugs operate after the engine starts. The ECM controls the post-heat time
based upon ECT information. If the ECT fails the ECM will operate pre-post heat time strategies with default
values from its memory. In this case, the engine will be difficult to start.
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ENGINE MANAGEMENT SYSTEM
1
REPAIR ENGINE CONTROL MODULE (ECM)
Service repair no - 18.30.03
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery negative lead.
3.Remove RH seat cushion, release clip and
remove ECM access panel.
4.Remove 3 bolts, release ECM and disconnect 2
multiplugs. Remove ECM.
Refit
5.Position new ECM and connect multiplugs.
6.Fit ECM and tighten bolts.
7.Fit access panel and RH seat cushion.
8.Reconnect battery negative lead.
9.Fit battery cover and secure with fixings.SENSOR - ENGINE COOLANT TEMPERATURE
(ECT)
Service repair no - 18.30.10
Remove
1.Disconnect battery negative lead.
2.Remove spring clip and disconnect ECT sensor
multiplug.
3.Position cloth around ECT sensor to absorb
coolant spillage.
4.Remove ECT sensor.
5.Remove sealing washer and discard.
Refit
6.Clean sealing washer, sensor threads and
sensor location.
7.Coat sensor threads with Loctite 577 and fit new
sealing washer.
8.Fit ECT sensor and tighten to20 Nm (14 lbf.ft).
9.Fit spring clip to multiplug and connect multiplug
to ECT sensor.
10.Top up cooling system.
11.Run engine to normal operating temperature.
Check for leaks around ECT sensor.
12.Reconnect battery negative lead.
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