1999 LAND ROVER DEFENDER length

ENGINE MANAGEMENT SYSTEM
23
DESCRIPTION AND OPERATION MODULATOR - EXHAUST GAS REGULATOR (EGR)
The EGR modulator is located on the RH side inner front wing. It regulates the vacuum source to the EGR valve
allowing it to open or close. The ECM utilises the EGR modulator to control the amount of exhaust gas being
recirculated in order to reduce exhaust emissions and combustion noise. Optimum EGR is usually obtained when
the vehicle is operating at light throttle openings, and the vehicle is cruising at approximately 2000 to 3000
rev/min.
Input / Output
The EGR modulator (C0191-1) receives a feed from the main relay (C0063-87) on a brown/orange wire via header
294. The earth path for the modulator (C0191-2) is controlled by the ECM (C0158-3) on a blue wire. The length of
time the ECM supplies an earth is how long the exhaust gases are allowed to recirculate. The ECM decides how
long to supply the earth by looking at engine temperature and engine load.
The EGR modulator can fail in one or more of the following ways:
Solenoid open circuit.
Short circuit to vehicle supply.
Short circuit to earth.
In the event of an EGR modulator failure, the EGR system will become inoperative.
WARNING LAMP - GLOW PLUG
The glow plug warning lamp is located in the instrument pack. It illuminates to alert the driver that the glow plugs
are being heated prior to the engine being started. The length of time that the lamp illuminates and the glow plugs
are operating prior to cranking is the pre-heat period. The length of time of this period is determined by the ECT
sensor signal, controlled by the ECM.
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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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18ENGINE MANAGEMENT SYSTEM
28
DESCRIPTION AND OPERATION OPERATION
Engine Management
The ECM controls the operation of the engine using stored information within its memory. This guarantees
optimum performance from the engine in terms of torque delivery, fuel consumption and exhaust emissions in all
operating conditions, while still giving optimum driveability.
The ECM will receive information from its sensors under all operating conditions, especially during:
Cold starting.
Hot starting.
Idle.
Wide open throttle.
Acceleration.
Adaptive strategy.
Backup strategy for sensor failures.
The ECM receives information from various sensors to determine the current operating state of the engine. The
ECM then refers this information to stored values in its memory and makes any necessary changes to optimise
air/fuel mixture and fuel injection timing. The ECM controls the air/fuel mixture and fuel injection timing via the
Electronic Unit Injectors (EUI), by the length of time the EUI’s are to inject fuel into the cylinder. This is a rolling
process and is called adaptive strategy. By using this adaptive strategy the ECM is able to control the engine to
give optimum driveability under all operating conditions.
During cold start conditions the ECM uses ECT information to allow more fuel to be injected into the cylinders.
This, combined with the glow plug timing strategy supplied by the ECM, facilitates good cold starting.
During hot start conditions, the ECM uses ECT and FT information to implement the optimum fuelling strategy to
facilitate good hot starting.
During idle and wide open throttle conditions, the ECM uses mapped information within its memory to respond to
input information from the TP sensor to implement the optimum fuelling strategy to facilitate idle and wide open
throttle.
To achieve an adaptive strategy for acceleration, the ECM uses input information from the CKP sensor, the TP
sensor, the ECT sensor, the MAP/IAT sensor, and the FT sensor. This is compared to mapped information within
its memory to implement the optimum fuelling strategy to facilitate acceleration.
Fuel Delivery / Injection Control
The fuel delivery/injection control delivers a precise amount of finely atomised fuel to mix with the air in the
combustion chamber to create a controlled explosion. To precisely control fuel delivery and control fuel injection,
the following input conditions must be met:
CKP information.
Injection timing map information.
FT information.
ECT information.
The ECM monitors the conditions required for optimum combustion of fuel in the cylinder from the various sensors
around the engine and then compares it against stored information. From this calculation, the ECM can adjust the
quantity and timing of the fuel being delivered into the cylinder. The ECM uses CKP information as follows:
To calculate engine speed.
To determine engine crankshaft position.
Engine speed and crankshaft position allows the ECM to determine fuel injection timing.
The ECM also uses ECT and FT information to allow optimum fuel delivery and injection control for all engine
coolant and fuel temperatures.
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FRONT SUSPENSION
1
REPAIR PANHARD ROD - FROM 02MY
Service repair no - 60.10.07.
Remove
1.Remove fixings at mounting arm.
2.Remove fixings at axle bracket.
3.Remove panhard rod.
4.Using a suitable length of steel tubing, press out
flexible bushes. Ensure tubing locates on outer
edge of bush and not on rubber inner.
Refit
5.Fit replacement bushes.
CAUTION: Apply pressure to outer edge of
bush, and not rubber inner.
6.Fit panhard rod to axle bracket and mounting
arm. Tighten fixings to230 Nm (170 lbf/ft).BEARINGS - FRONT HUB
Service repair no - 60.25.14
Remove
1.Raise front of vehicle.
WARNING: Support on safety stands.
2.Remove front road wheel.
3.Pull back front brake caliper jump hose shield
and clamp brake hose.
4.Position container collect brake fluid.
5.Loosen brake pipe to jump hose union and
disconnect.
CAUTION: Use 2 spanners when loosening
or tightening unions.
6.Remove 2 bolts securing brake caliper to hub.
7.Remove brake caliper.
CAUTION: Plug the connections.
8.Remove dust cap.
9.Remove circlip and shim(s) from drive shaft.
10.Remove and discard 5 bolts securing driving
member to hub.
11.Remove driving member and discard gasket.
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PANEL REPAIRS
5
PROCEDURES Welding
13.When plug welding, begin weld approximately 15
mm (0.6’) from hole. This will allow the weld
area to be preheated which will enhance weld
penetration. It also allows the operator to see
more easily where penetration takes place. Fill
hole with weld by moving in a circular direction
around the hole.
14.When MIG seam welding do not carry out
lengthy operations. Divide the welds into short
operations, this will reduce the chances of
overheating the workpiece which inturn will avoid
distortion and strain.
15.Dress all welds using a sander with 36 grit disc,
or a belt-type sander and/or wire brush.
CAUTION: Only use a Stainless Steel wire
brush for Aluminium.
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ELECTRICAL
1
ADJUSTMENT HEADLAMPS - ALIGN BEAM
Service repair no - 86.40.17
Check
1.Align suitable beam setting equipment to
headlamp.
2.Ensure headlamp height adjustment switch set
to’O’and headlamps switch on.
Headlamp setting = 1.2% below horizontal and
parallel.
Adjust
3.Align beam setting equipment to 2nd headlamp
and adjust 2nd lamp as necessary.
4.Switch off headlamps.
5.Remove beamsetter.SOLENOID/MOTOR - FRONT DOOR - ADJUST
Service repair no - 86.26.21
Adjust
1.Remove door trim casing.See CHASSIS AND
BODY, Repair.
M86 5629
2.Carefully peel back plastic sheet to expose
mechanism.
3.Release clip and detach solenoid link from latch.
M86 5630
4.Ensure sill button is fully raised.
5.Fully extend solenoid actuator then lower 3.5
mm +/- 1.00 mm.
6.Whilst holding actuator in this position, adjust
length of link, until link pin is aligned with hole in
latch lever.
7.Connect link and secure with clip.
8.Secure plastic sheet.
9.Fit door trim casing.See CHASSIS AND
BODY, Repair.
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