1999 LAND ROVER DEFENDER air conditioning

ENGINE
31
REPAIR All Models
6.Remove 3 bolts securing centrifuge to engine oil
cooler.
7.Remove centrifuge and discard’O’ring.
8.Remove 2 bolts, remove drain pipe from
centrifuge and discard gasket.Refit
9.Clean mating faces of centrifuge, oil cooler and
sump.
10.Position drain pipe to centrifuge using new
gasket and tighten bolts to10 Nm (7 lbf.ft).
11.Position new’O’ring to oil cooler.
12.Position centrifuge and tighten bolts to25 Nm
(18 lbf.ft).
13.Align drain pipe to sump, fit new gasket and
tighten bolts to10 Nm (7 lbf.ft)
Models with air conditioning only
14.Position compressor and tighten bolts to25 Nm
(18 lbf.ft).
15.Fit auxiliary drive belt.See ELECTRICAL,
Repair.
All Models
16.Fit turbocharger.See FUEL SYSTEM, Repair.
17.Fit underbelly panel.See CHASSIS AND
BODY, Repair.
ProCarManuals.com

ENGINE MANAGEMENT SYSTEM
3
DESCRIPTION AND OPERATION 1.Mass Air Flow (MAF) sensor.
2.Engine Coolant Temperature (ECT) sensor.
3.Glow plugs.
4.Manifold Absolute Pressure (MAP) / Inlet Air Temperature (IAT) sensor.
5.Fuel pump relay.
6.Engine Control Module (ECM).
7.Air Conditioning (A/C) and cooling fan relay.
8.Fuel Temperature (FT) sensor.
9.Crankshaft Speed and Position (CKP) sensor.
10.Electronic Unit Injectors (EUI).
11.Ambient Air Pressure (AAP) sensor.
ProCarManuals.com

ENGINE MANAGEMENT SYSTEM
5
DESCRIPTION AND OPERATION DESCRIPTION
General
An engine control module (ECM) controls the five cylinder direct injection diesel engine, and works on the drive by
wire principal. This means there is no throttle cable, the ECM controls the drivers needs via a signal from the
Throttle Position (TP) sensor on the throttle pedal.
The ECM is a full authoritative diesel specific microprocessor that also incorporates features for air conditioning. In
addition, the ECM supplies output control for the Exhaust Gas Recirculation (EGR) and turbocharger boost
pressure. The ECM has a self diagnostic function, which is able to provide backup strategies for most sensor
failures.
The ECM processes information from the following input sources:
Mass Air Flow (MAF) sensor.
Ambient Air Pressure (AAP) sensor.
Manifold Absolute Pressure (MAP) / Inlet Air Temperature (IAT) sensor.
Engine Coolant Temperature (ECT) sensor.
Crankshaft Speed and Position (CKP) sensor.
Throttle Position (TP) sensor.
Fuel Temperature (FT) sensor.
Air conditioning request.
Air conditioning fan request.
Brake pedal switch.
Clutch pedal switch.
The input from the sensors constantly updates the ECM with the current operating condition of the engine. Once
the ECM has compared current information with stored information within its memory, it can make any adjustment
it requires to the operation of the engine via the following:
Air conditioning clutch relay.
Air conditioning cooling fan relay.
Electronic vacuum regulator solenoid.
Fuel pump relay.
Glow plug warning lamp.
Glow plugs.
Fuel injectors.
Main relay.
Turbocharger wastegate modulator.
Temperature gauge.
The ECM interfaces with the following:
Serial communication link.
Instrument pack.
ProCarManuals.com

COOLING SYSTEM
1
ADJUSTMENT DRAIN AND REFILL
Service repair no - 26.10.01
WARNING: Hot coolant
Drain
1.Remove engine acoustic cover.
2.Visually check engine and cooling system for
signs of coolant leaks.
3.Examine hoses for signs of cracking, distortion
and security of connections.
4.Position drain tray to collect coolant.
5.Remove expansion tank filler cap.
6.Loosen clip screws securing air inlet hose to
intercooler and inlet manifold, release and
remove hose.
7.Release clip and disconnect bottom hose from
radiator.
8.Allow cooling system to drain.
9.Disconnect bottom hose from radiator.Refill
1.Flush system with water under low pressure.
2.Do not use water under high pressure as it could
damage the radiator.
3.Connect bottom hose to radiator and secure
hose with clip.
4.Prepare coolant to required concentration.
5.Position heater temperature control to maximum
hot position.
6.Remove bleed screw from top hose.
7.Fill system slowly through coolant expansion
tank until a steady flow of coolant is emitted from
the bleed hole in top hose.
8.Fit bleed screw to top hose.
9.Continue filling system until coolant level
reaches’MAX’mark on expansion tank.
10.Fit expansion tank filler cap.
11.Position air intake hose and tighten clip screws.
12.Start and run engine until normal running
temperature is reached.
13.If fitted, DO NOT operate air conditioning.
14.Switch off engine and allow to cool.
15.Check for leaks and top-up coolant to’MAX’
mark on expansion tank.
ProCarManuals.com

PANEL REPAIRS
1
REPAIR WING LOWER FRONT
Remove
1.Disconnect both battery leads, negative lead
first. system.
2.Remove wheel arch eyebrow.
3.Remove wheel arch liner.
4. RH side:Remove aerial.
5.Remove air intake hose.
6.Remove bolts securing lower wing.
Refit
7.Prepare and clean panel joint faces.
8.Reverse removal procedure.HEADLAMP MOUNTING PANEL
Remove
1.Disconnect both battery leads, negative lead
first.
2.Disconnect all ECUs.
3.Remove radiator.See COOLING SYSTEM,
Repair.
4.Recover refrigerant from A/C system.See AIR
CONDITIONING, Repair.
5.Remove headlamp.See ELECTRICAL,
Repair.
6. LH side:Remove screen washer bottle.See
WIPERS AND WASHERS, Repair.
7. RH side:Position PAS reservoir aside.
8.Remove bolts and release welds securing panel,
remove panel.
Refit
9.Prepare and clean panel joint faces. Punch or
drill holes in new panel for plug welding as
shown.
10.Reverse removal procedure.
ProCarManuals.com

77PANEL REPAIRS
2
REPAIR WING UPPER - LH
Remove
1.Disconnect both battery leads, negative lead
first.
2.Remove headlamp.See ELECTRICAL,
Repair.
3.Remove headlamp mounting panel.See this
Section.
4.Remove radiator.See COOLING SYSTEM,
Repair.
5.Recover refrigerant from A/C system.See AIR
CONDITIONING, Repair.
6.Remove receiver drier.See AIR
CONDITIONING, Repair.
7.Remove relevant A/C pipes.
8.Remove relevant heater intake pipes.
9.Remove screen washer bottle.
10.Remove wheel arch liner.See CHASSIS AND
BODY, Repair.
11.Remove bolts and release welds securing panel,
remove panel.
Refit
12.Prepare and clean panel joint faces.
13.Reverse removal procedure.
14.Align headlamps.See ELECTRICAL,
Adjustment.WING UPPER - RH
Remove
1.Disconnect both battery leads, negative lead
first.
2.Remove headlamp.See ELECTRICAL,
Repair.
3.Remove headlamp mounting panel.See this
Section.
4.Remove radiator.See COOLING SYSTEM,
Repair.
5.Recover refrigerant from A/C system.See AIR
CONDITIONING, Repair.
6.Remove relevant A/C pipes.
7.Position PAS reservoir aside.
8.Remove wheel arch liner.See CHASSIS AND
BODY, Repair.
9.Remove aerial.
10.Remove vacuum solenoid valve.
11.Release clips securing coolant reservoir.
12.Remove bolts and release welds securing panel,
remove panel.
Refit13.Prepare and clean panel joint faces.
NOTE: LH panel shown
14.Reverse removal procedure.
15.Align headlamps.See ELECTRICAL,
Adjustment.
ProCarManuals.com

82 - AIR CONDITIONING
CONTENTS
Page
ADJUSTMENT
REFRIGERANT RECOVERY, RECYCLING, RECHARGING 1.............................
REPAIR
COMPRESSOR 1...................................................................................................
MOTOR - CONDENSER FAN 2..............................................................................
RECEIVER DRIER 2...............................................................................................
RELAY - TEMPERATURE CONTROL - FROM 02MY 3.........................................
EVAPORATOR 4....................................................................................................
ProCarManuals.com

AIR CONDITIONING
1
ADJUSTMENT REFRIGERANT RECOVERY, RECYCLING,
RECHARGING
Service repair no - 82.30.02
WARNING: The air conditioning system is
charged with a high pressure, potentially
toxic refrigerant. Repairs or servicing must
only be carried out by an operator familiar with
both the vehicle system and the charging and
testing equipment.
WARNING: All operations must be carried
out in a well ventillated area away from
open flame and heat sources.
WARNING: Wear eye and hand safety
protection.
CAUTION: Overcharging air conditioning
system will cause excessive head
pressure.
An air conditioning portable Refrigerant Recovery
Recycling Recharging Station for use with R134a
refrigerant incorporates all the features necessary to
recover R134a refrigerant from the air conditioning
system; to filter and remove moisture; to evacuate and
recharge with the reclaimed refrigerant. The unit can
also be used for performance testing and air
conditioning system analysis.
The operator must adhere to the equipment
manufacturer’s instructions.
Refrigerant Recovery
1.Remove dust caps from high and low pressure
connectors.
2.Connect high and low pressure hoses to
appropriate connections.
3.Open valves on connectors.
4.Turn valves on refrigerant station to correct
positions.
NOTE: Operate the refrigerant station in
accordance with the manufacturers
instructions.
5.Turn Process switch to correct position.
6.Turn Main switch to’ON’.
7.Allow station to recover refrigerant from system.8.Close valves on refrigerant station.
9.Turn Main switch to’OFF’.
10.Close valves on connectors.
11.Disconnect high and low pressure hoses from
connectors.
12.Fit dust caps to connectors.
13.Open tap at rear of station to drain refrigerant oil
recovered from system.
14.Measure and record quantity of refrigerant oil
recovered from system.
15.Close tap at rear of station.
Evacuation
CAUTION: Whenever the refrigerant
system is opened, the receiver/drier must
be renewed immediately before evacuating
and recharging the system.
1.Remove dust caps from high and low pressure
connectors.
2.Connect high and low pressure hoses to
appropriate connections.
3.Open valves on connectors.
4.Turn valves on refrigerant station to correct
positions.
5.Turn Process switch to correct position.
6.Turn Main switch to’ON’.
7.Allow station to evacuate system.
NOTE: If the vacuum reading is below
700mmHg after 15 minutes, suspect a leak
in the system. Partially recharge the
system and check for leaks using an electronic
leak tester. Check suction lines first, then run the
compressor for 5 minutes. Next check the high
pressure lines.
NOTE: The system must be evacuated
immediately before recharging
commences. Delay between evacuation
and recharging is not permitted.
ProCarManuals.com