1994 JAGUAR XJ6 climate control system

Introduction
FOREWORD
This Vehicle Service Manual (VSM) is Dart
-
of a
set of service literature which covers -. diagnosis and rectification of problems associated with all areas of the X300 family of vehicles.
It is designed to be read in conjunction with other manuals, namely the various Unit Service Manuals (USM) (as
applicable to the particular vehicle under diagnosis/ repair) and the X300 Electrical Diagnostic Manual (EDM); see list
below.
It should be noted that its scope is limited to those areas that are unique to the family, e.g. Remove & Refit procedures
for Body Components, Engine, Transmission etcetera, Fuel, Emissions & Engine Management systems, and so on.
Fault Diagnosis and repair procedures (together
with Technical Data, Recommended Lubricants, Capacities etcetera) for major assemblies such as engines, automatic and manual transmissions, are covered in the separate Unit Service
Manuals.
The Unit Service Manuals are notvehicle
-specific, but are designed to be read in conjunction with this VSM, and, where so equipped, with other Jaguar Vehicle Service Manuals for new models launched subsequent to the X300 family.
The X300 Electrical Diagnostic Manual is the final part of the 'set' of service documentation. This manual
is
family-specific, and is designed to aid theTechnician to isolate electrical faults and to correct them. It covers all aspects
of electrical fault diagnosis, including:
OBD
II Codes and emission control system related fault diagnosis / rectification.
Circuit Diagrams
Component (Relays, fuse boxes, control modules etcetera) Location
/ Harness Diagrams I Ground Locations
Connector Locations.
Service Manuals Required
The Manuals required to service the X300 family of vehicles are as follows:
X300 Vehicle Service Manual
X300 Electrical Diagnostic Manual
Unit Service Manuals:
AJ16 Engine Service Manual
VI2 Engine Service Manual ZF AutomaticTransmissions Service Manual (ZF supplies transmissions for 3.2 liter and 4.0 liter normally aspirated
versions) Powertrain Automatic Transmissions Service Manual (The Powertrain name succeeds that of Hydra
-Matic.
Powertrain are suppliers of the 4L 80 E transmission as fitted to 4.0 litre supercharged and 6.0 litre versions)
Each
of the X3Okpecific manuals is divided into Sections which adopt the same title and number where relevant, i.e. Section 5.1 of both the VSM and the EDM cover Fuel, Emission Control & Engine Management System (AJ16). An
over
-all contents list showing each section title and number together with its page-edge locator is given in this section
and in the introduction to the EDM.
The VSM (not applicable to the EDM) also contains Appendices which cover specialized areas such as the current
vehicle specification, routine maintenance schedule etc. These are carried at the rear of this Manual, and have their
own contents page within this section.
INDEX
rapid location of information. The entries are set out as per the following example: @ This manual carries a comprehensive index at the rear, which is designed to save the Technician time by permitting
CLIMATE CONTROL SYSTEMS. Section 14.
See also Electrical Diagnostic Manual
Clutch
Description: Sect. 7.7 - 10
Fault diagnosis: Sect 7.1 - 11
In the example the heading in upper case lettering is to a section title, and it refers to the section number, 14, and also to the EDM as electrical diagnostic information will be found in that manual's section 14. The entry for clutch tells us that the relevant description will be found on page 10 of Section 7.1 of this manual, and
that fault diagnosis procedures start on page 11. In this case there is no reference to the EDM as electrical diagnosis does not apply to this area.
GLOSSARY OF TERMS
This Section contains a Glossary of general and emissions-related terminology (commencing on page 5).
X300 VSM 1 Issue 1 August 1994

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Contents
Fuel, Emission Control & Engine Management (AJI 6)
Manual Transmission & Clutch (AJl6)
Driveshafts & Final Drive
Suspension Systems
Body Components & Trim
Climate Control Systems
Issue 1 August 1994 3 x300
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Cooling System
SECTION CON TENTS
Sub-section Title SRO Page
I to IV ............ Preliminary Pages .................................................................... i
4.7.7 ............. Cooling System Description ........................................................... 7
4.1.7.7 ........... Cooling System Description. Major Components .......................................... 7
4.7.7.2 ........... Cooling System Description. Components for Climate Control System ........................ 7
4.7.1.3 ........... Cooling System Description. Components for Superchargwl Engine .......................... 7
4.7.7.4 ........... Cooling System Description. Operation .................................................. 7
4.7.2 ............. Cooling System Configuration .......................................................... 2
4.7.3 ............. Service Procedures ................................................................... 3
4.7.3.7 ........... Service Procedures. Safety Precautions .................................................. 3
4.7.3.2
........... Service Procedures. Working Practices .................................................. 3
4.7.3.3
........... Service Procedures. Coolant Change .................................................... 3
4.7.4.
............ Drain and Fill Procedures ............................................................. 4
4.7.4.7
........... Drain and Fill Procedures. Radiator, Drain ............................................... 4
4.7.4.2
........... Drain and Fill Procedures. Engine. Drain ................................................. 4
4.1.4.3
........... Drain and Fill Procedures. Radiator, Fill ................................................. 4
4.7.4.4
........... Drain and Fill Procedures. Complete System. Fill .......................................... 5
4.7.5 ............. Fault Diagnosis ...................................................................... 6
4.1.5.7 ........... Fault Diagnosis. Introduction ........................................................... 6
4.7.5.2 ........... Fault Diagnosis. Diagnostic Procedures .................................................. 6
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Cooling System (AJl6) m
4.1.1 COOLING SYSTEM DESCRIPTION
4.1.1.1 Major Components
o Main engine crossflow radiator, incorporating a concentric tube cooler for the power steering fluid mounted in
the right
-hand radiator side tank. Vehicles with automatic transmission have a transmission fluid cooler
mounted in the left
-hand radiator side tank; for 4,O liter supercharged engines a six-plate cooler is fitted; other
vehicles have
a tube-type cooler. Adouble-action temperature switch, for controlling the radiator cooling fans,
is mounted in the left
-hand radiator side tank.
0 Two electrically operated radiator cooling fans, mounted behind the main radiator.
0 Coolant circulating pump, belt driven from the engine crankshaft.
0 Coolant header tank with pressure relief cap and coolant level probe.
o Engine thermostat.
4.1.1.2
0 Heater matrix.
o Electrically operated coolant circulating pump, mounted on the left-hand side of the engine bulkhead.
o Solenoid operated valve, located adjacent to the coolant circulating pump.
Components for Climate Control System
4.1.1.3 Components for Supercharged Engine
0 0 Supercharger crossflow radiator, mounted in front of the main radiator. The supercharger radiator is reverse- circuited, i.e. the coolant inlet is at the bottom of the radiator.
0 Electrically operated coolant circulating pump, located at the left-hand side of the main radiator.
4.1.1.4 Operation
The configuration of the cooling system for normally aspirated and supercharged (4,O liter) engines is shown in Sub- section 4.1.2.
The cooling system is pressurized, which allows the system to operate at a higher temperature without overheating.
The header tank is fitted with a pressure relief cap to protect the system against overpressure.
Under cold start conditions, coolant is forced by the engine driven water pump through the cylinder block and cylinder
head to the thermostat housing. The thermostat is closed to give rapid engine warm up, hence the coolant is returned
directly to the water pump inlet. When normal engine operating temperature is reached, the thermostat opens and
coolant is diverted through the radiator before returning to the water pump inlet. In vehicles fitted with
a supercharger,
coolant is circulated through the supercharger radiator and intercooler by the supercharger water pump. The super- charger cooling circuit uses the same coolant header tank as the main engine cooling system.
The radiator cooling fans operate in series and parallel under the control of the double
-action radiator mounted tem- perature switch. The fans are also controlled by the climate control system on vehicles fitted with air conditioning.
Under hot operating conditions, the fans may continue to operate after the engine has been switched off. The fans
stop automatically when the coolant temperature has been reduced sufficiently.
The system also provides the coolant supply for the climate control system, which is described in Section
14.
X300 VSM 1 Issue 1 August 1994

area washed to remove all traces of coolant.
CAUTION: To prevent the possibility of damage to the heater circuit pump and supercharger pump (where fitted),
the pumps should be electrically isolated if the ignition has to be turned ON while the cooling system is
drained.
WARNING: DO NOT REMOVE THE HEADER TANK PRESSURE CAP WHILE THE ENGINE IS HOT. IF THE CAP MUST
BE REMOVED, PROTECT THE HANDS AGAINST ESCAPING STEAM AND SLOWLY TURN THE CAP ANTI
- CLOCKWISE UNTIL THE EXCESS PRESSURE CAN ESCAPE. LEAVE THE CAP IN THIS POSITION UNTIL
ALL THE STEAM AND PRESSURE HAS ESCAPED AND THEN REMOVE THE CAP COMPLETELY.
WARNING: WHEN DRAINING THE COOLANT WITH THE ENGINE HOT, PROTECT THE HANDS AGAINST CONTACT
WITH HOT COOLANT.
WARNING: WHEN WORKING WITHIN THE ENGINE COMPARTMENT, KEEP CLEAR OF THE RADIATOR COOLING
FANS. THE FANS COULD START WITHOUT WARNING EVEN IF THE ENGINE IS NOT RUNNING.
4.1.3.2 Working Practices
Whenfilling thesystem with coolant,ensurethatthevehicle isstanding on a level surfaceandthatthecoolant is poured
in slowly so that airlocks are not introduced into the system. Airlocks can seriously affect the operation of the climate
control system and can cause damage to the heater circuit pump (and supercharger circuit pump if fitted).
Cooling System (AJ16)
4.1.3 SERVICE PROCEDURES
4.1.3.1 Safety Precautions
The anti-freeze specified in Appendix AI must be used wherever possible. It is designed to afford the maximum cor- rosion protection to all metals found in the engine cooling system, as well as having the frost protection properties
necessary during the winter months.
Should
it not be available, then anti-freeze conforming to Ford Motor Company specification ESLbM97B49-A may be
used. To provide optimum temperature and corrosion protection, the specified anti-freeze concentration must always
be used.
Once coolant has been drained from the system,
it must be discarded and not reused. Anti-freeze is harmful to the
environment. Used coolant must be disposed of safely and never poured down a drain connected to the public sewer.
CAUTION: Never fill or topup the system with water only.
CAUTION : Anti-freeze is harmful to paintwork. Coolant spillages must be wiped up immediately and the affected
Hose clips should always be positioned so that there is proper access for tightening and that the clip does not foul or
interfere with the operation of any components.
Drive belts must always be tensioned to the specified value and the tension checked
at the correct point on the belt.
This information is given in Subsection IV in the preliminary pages.
0
When tightening components, the torque figures given in Sukection II in the preliminary pages should always be
used for the fastenings listed.
4.1.3.3 Coolant Change
The coolant must be changed at intervals of four years. The system should be drained from the radiator drain plug,
flushed and filled with fresh coolant. Flushing should be carried out thoroughly to remove all the old coolant from the
engineand heater matrix. (The heatervalve isopen withthe ignition OFF). AfterfiIling,checkthecoolant concentration
with a hydrometer. For the specified anti-freeze and coolant concentration, see Appendix AI.
X300 VSM 3 Issue 1 August 1994

€3 Cooling System (AJ16)
4.1.4 DRAIN AND FILL PROCEDURES
4.1.4.1 Radiator, Drain
. Place a drain tray in position underthe radiator drain plug
. Remove the header tank pressure cap. Release the captive
Tighten the radiator drain plug.
CAUTION: This procedure does not drain the heater circuit.
(Fig. 1).
radiator drain plug and drain the coolant.
4.1.4.2 Engh-, Drain
m:
. Drain the radiator. (See the procedure above).
. Place a drain tray under the cylinder block drain plug (Fig.
Remove the block drain plug and drain the coolant.
. Fit the block drain plug.
This procedure
should only be necessary when the
engine is being dismantled.
2).
Fig. 1
Fia. 2
WAm. DO NOT REMOVE THE HEADER TANK PRESSURE CAP WHILE THE ENGINE IS HOT. IF THE CAP MUST
BE REMOVED, PROTECT THE HANDS AGAINST ESCAPING STEAM AND SLOWLY TURN THE CAP ANTI- CLOCKWISE UNTIL THE EXCESS PRESSURE CAN ESCAPE. LEAVE THE CAP IN THIS POSITION UNTIL ALL THE STEAM AND PRESSURE HAS ESCAPED AND THEN REMOVE THE CAP COMPLETELY.
WARNING: WHEN DRAINING THE COOLANT WITH THE ENGINE HOT, PROTECT THE HANDS AGAINST CONTACT
WITH HOT COOLANT.
4.1.4.3 Radiator, Fill
. Add coolant until the level in the header tank is steady at MAX. (Do not fit the header tank cap).
. Switch on the ignition. (The climate control system must be OFF).
Start the engine and wait until the cooling fans operate for the second time. (The engine speed may be raised to
While the cooling fans are operating, raise the engine speed to 1500 RPM for one minute. Return to idle speed.
. Switch off the ignition and wait for one minute.
Check that the coolant level in the header tank is between MAX and 10 mm above MAX. Add coolant as necessary.
Fit the header tank cap.
reduce
the warm up time).
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Cooling System (AJ1
4.1.4.4 Complete System, Fill
. Add coolant until the level in the header tank is steady at MAX. (Do not fit the header tank cap).
m Switch on the ignition. (The climate control system must be OFF).
Start the engine and wait until the cooling fans operate for the second time. (The engine speed may be raised to
. While the cooling fans are operating, raise the engine speed to 1500 RPM for one minute. Return to idle speed.
. Turn the climate control system ON. Set the temperature to HI. Manually select a fan speed of approximately 50%.
. Run the engine for four minutes. Ensure that the climate control system outlet airtemperature is hot to very hot and
that there is no noise from the heater coolant circulating pump. (The engine speed may be raised to assist with heat- ing).
reduce the warm up time).
. Switch off the ignition and wait for one minute.
. Check that the coolant level in the header tank is between MAX and 10 mm above MAX. Add coolant as necessary.
Fit the header tank cap.
X300 VSM 5 Issue 1 August 1994

4.1.5 FAULT DIAGNOSIS
4.1.5.1 Introduction
The following diagnostic procedures are provided to assist properly qualified persons to identify and rectify the faults
in the system which are most likely to be encountered. Reference is made to the Electrical Diagnostic Manual (EDM),
which should be consulted for all electrical faults. When investigating faults relating to temperature, the prevailing
ambient temperature conditions should be taken into account. The climate control system is dealt with in Section 14.
Possible Cause
Thermostat stuck closed
Incorrect thermostat rating
Faulty temperature gauge
Faulty temperature transmitter
4.1.5.2 Diagnostic Procedures
Check
Test thermostat
Check thermostat operating
temperature
Refer to EDM
Refer to EDM
Symptom
herheating
Cooling fan(s) not operating 3verheating at
dle
roo cold
Refer to EDM
Incorrect thermostat rating
Thermostat not fitted
Cooling
fan(s) operating con-
tinuously Faulty temperature gauge
Faulty temperature transmitter
Radiator
core blocked
Radiator grille obstructed
Check thermostat operating
temperature
Remove thermostat housing
and inspect
Refer to EDM
Refer to EDM
Refer to EDM
Concentration of
anti
-freeze too high
Drive belt slack
Drive belt broken
Water pump seized
Insufficient coolant
Internally collapsed hoses
Incorrect ignition timing
Fuel
/ air mixture too weak
Incorrect valve
timing
Cylinder head gasket leaking
Brakes binding Check
for
hotspots in radiator
Check grille for obstruction
Check strength of coolant
Check belt tension
Visual check
Slacken drive belt and turn
water
pump pulley by hand.
Check belt for damage
Check coolant level
Pressure test system and
check for deformation of hoses
Refer to EDM
Refer to EDM
Check valve
timing
Pressure-test system. (Check
for contamination of coolant
in header tank)
Check brake calipers for stick
-
ing pistons and seized brake
pad pins
Thermostat stuck open
I Test thermostat
Remedy
Renew thermostat
Renew thermostat
Renew gauge
Renew transmitter
Flush
or renew radiator
Remove obstruction from
grille
Drain and fill
with coolant of
correct concentration
Adjust belt to correct tension
or renew belt
if worn
Renew belt
Renew water pump. Renew
drive belt
if required
Top-up coolant
Renew hoses as required
Rectify
as required
Rectify
as required
Correct valve
timing
Renew head gasket
Rectify
as required
Rectify
as required
Renew thermostat
Renew thermostat
Fit thermostat
Rectify
as required
Renew gauge
Renew transmitter
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Issue 1 August 1994 X300 VSM