check engine JAGUAR XJ6 1994 2.G Owner's Manual

10.2 SERVICE
PROCEDURES - SAFETY RELATED
10.2.1
Airbag
The electrically activated driver's side airbag is attached to the steering wheel hub and is fed by two wires from the
column stalk assembly. Electrical input to the column stalk assembly for the airbag is provided by a dedicated harness
which is encased in a yellow sleeve. A mechanism in the stalk assembly called the 'cable reel cassette' provides conti
-
nuity from the static column to the steering wheel. The 'cable reel cassette' is driven by a tang which locates in the
steering wheel. Because the connection is by wires, and the cassette assembly is only capable of approximately five
(5) full turns,
it is critically important that initial positioning is correct, see Section 15. It is equally important that fitting of the steering wheel, connection of the column, lower shaft and steering rackshould
ONLY be made with the steering rack in the center of its travel.
WARNING: DO NOT REMOVE THE STEERING COLUMN FROM THE VEHICLE WITH THE STEERING WHEEL AT- TACHED UNLESS THE STEERING IS CENTERED AND THE COLUMN LOCK IS ENGAGED. IF THE LOCK
BARREL
IS TO BE RENEWED, 'LOCK-WIRE THE ASSEMBLY TO PREVENT ROTATION. FAILURE TO OB- SERVE THIS AND CONSEQUENT DAMAGE TO THE 'CABLE REEL CASSETTE MAY RESULT IN AN INOP- ERATIVE AIRBAG SYSTEM. SEE LABEL ON STEERING WHEEL HUB.
10.3 SERVICE PROCEDURES
10.3.1 Working Practices
It is not recommended that either the steering rack or engine driven pump assemblies are repaired in any way other
than in accordance with the repair procedures described in this manual. The fluid reservoir and filter is a disposable
assembly and no attempt should be made to clean it internally. Genuine replacement units must be fitted following
routine service or diagnostic confirmation of the failure of any component.
The importance of cleanliness cannot be over
-stressed, not only with new parts but also those which may havefailed.
In-service contamination of the hydraulic system is a major cause of failures and may be avoided with good working
practices and care. All new units and pipes must be supplied with suitable blanks in every orifice. Should a unit not
have blanks fitted, do not use
it - return it to the supplier with an appropriate reason for your action.
To help the manufacturer diagnose problems and avoid post-removal contamination; provide full details of the fault
and plug all connections as soon as they are released. All suspect units must be returned to Jaguar Cars complete
with relevant documentation.
CAUTION: It is imperative that the power steering system does not become contaminated in any way. Always de- cant fluid from afresh sealed container and clean the area around the reservoir neck both before and after topping-up. Never return drained fluid to the system.
10.3.2
Position the vehicle on a level surface with the engine sta- tionary and fluid cold. Add fluid, if required, so that the level
falls BETWEEN the marks
Fig.1.
10.3.3 System Bleed (following maintenance)
To avoid fluid aeration and possible pump damage, the in- itial fill process must be carried out with the ignition OFF.
Set the fluid level approximately 20 mm above the upper
dipstick level, and cycle the steering no less than three (3) times from lock to lock (this may be best achieved with the
front wheels off the ground). As air is expelled thefluid level
will fall, the level should be corrected. Start the engine and
further cycle thesteering until the fluid level becomes stable.
Stop the engine and finally set the level in accordance
with the fluid level check procedure.
10.3.4 Fluid Reservoir
The reservoir has an integral, non-serviceable, return-side
filter. Should any component be renewed or the system
'broken into' for any reason,
it is essential that the reservoir and the fluid are changed. Under normal operating condi- tions it is not necessary to change the fluid.
10.3.5 Hydraulic Connections
Fluid
Level Check and
Top-up
Jf7-281
Fig. 1
All hydraulic connections and surrounding areas should be scrupulously cleaned before and after work. Please note
that the steering rack valve block connections for FEED and RETURN are common in size. Ensure that the pipes are
correctly fitted, the uppermost one being the high pressure FEEDfrom the steering pump and the lower (RETURN) hav- ing a double depth hexagon tube nut.
X300 VSM 5 issue 1 August 1994

@ Steering
Cause
Fluid level low?
Drive belt slack
(V12)
Pump drive loose (6cyl)
center pressures low
Air in system due to loose connection
Pump shaft seal faulty (fluid loss)
Delivery pressure or flow too low
Return flow restricted by blocked reser
-
voir filter
Both check valves blocked
Rack damper too
tight
Lower column incorrectly set
Excessive upper column friction
Faulty rotary valve or seal
Drive belt slack
(VI217
Engine idle speed too low
Pump drive loose
(6cyl)
Air in system due to loose connection
Pump shaft seal faulty (fluid
loss)
Delivery pressure or flow too low
Fluid level low?
tire pressures
high
Air in system due to loose connection
Stiff or seized steering joint
Rack damper too tight
Castor or tracking error
Lower column over extended
Fluid level low?
Air
in system due to loose connection
Pump shaft seal faulty (fluid
loss)
Rack damper loose
Pinion bearing faulty
Rack or column fixings loose
Rack mounting bracket loose
Rack mounting bush loose
Free play in column assembly
10.4 DIAGNOSTIC PROCEDURE
10.4.1 Introduction
The following diagnostic procedures are provided to rapidly pin-point mechanical faults which are not interrogated
by electrical means. Diagnostic procedures which require dedicated electrically operated equipment are dealt with in the 'Electrical Diagnostic Manual' (EDM) but may be mentioned here for reference.
10.4.2 Preliminary Action
Before any problem solving is undertaken it is essential that the fluid level and where applicable, belt tension, is
checked and if required corrected.
CAUTION: It is imperative that the power steering system does not become contaminated in any way. Always de cant fluid from a fresh sealed container and clean the area around the reservoir neck both before and after
topping-up. Never return drained fluid to the system.
10.4.2 Diagnostic Chart 1
Remedy
Rectify fluid loss and or top up
Re
-tension belt
Renew pump
Set to specification
Secure connection and bleed air out
Renew pump
Renew pump
Renew reservoir
Renew rack
Renew rack
Set to specification
Renew upper column
Renew rack
Retension belt
Reset idle speed
Renew
pump
Secure connection and bleed air out
Renew
pump
Renew pump
Rectify
fluid loss and or top up
Set to specification
Secure connection and bleed air out
Test and renew faulty joint
Renew rack
Check geometry and rectify
if required
Set to specification
Rectify fluid
loss and or top up
Secure connection and bleed air out
Renew pump
Renew rack
Renew rack
Tighten to specification
Renew rack
Renew rack
Check and rectify as required
Trouble
Heavy on both sides
Heavy on one side
Heavy when steering
rapidly
Vague feel about center
Knocking
1 vibration felt
at steering wheel
0
0
0
0
Issue 1 August 1994 6 X300 VSM

@ Steering
10.4.4 Diagnostic chart 3
Trouble
Hydraulic noise when
turning lock to lock
Continuous pressure
relief valve operation
Continuous noise
Cause
Fluid level low?
Air ingress at connections
Air ingress through feed hose lining
or
skin
Air ingress at pump front seal
Water contamination caused by fractured
cooler pipe within engine coolant radi
-
ator
Pump starvation or cavitation caused by
twisted or trapped feed hose
Pump starvation caused by blocked filter
Worn
pump
High pressure hose (pump to rack) dam-
aged or restricted
Fluid level low?
Drive belt loose
(12 cyl only)
Drive pulley loose
Steering pump mounting
(4 loose
Drive 'dog' loose, slipping or incorrectly
fitted
(6 cyl only)-
Hose or pipe fretting on body or chassis
structure
Hose twisted or restricted
Remedy
Rectify fluid loss and or top up
Check and tighten all connections to spec
-
ification
Renew faulty
'0' rings or Dowty washers
Renew porous
1 damaged hoses
Renew
pump
Renew radiator. Flush and drain steering
system twice
minimum, check for noise
and system performance (Pump is most
susceptible to damage due to
loss of lu-
brication and may have to be renewed)
Reroute or relieve pressure
Renew reservoir
Renew pump
Renew hose
Rectify
fluid loss and or top up
Inspect for damage and renew as required
Tighten pulley to specification
Tighten to specification
Investigate
& rectify as required
Rectify routing
Rectify routing
Issue 1 August 1994 8 X300 VSM

Climate Control Systems
CONTROL MODULE FAULT & CONDITION SELF-ANALYSIS
0 14.6 14.6.1 System Health
The climate control system has a 'self-test' facility, accessible from the control panel. The self test sequence has two
basic modes:
0 System error information is stored in the A/CCM up to a maximum of five faults. Should a fault occur there will
be an audible 'beep' and the message 'Er' will be displayed on the control panel LCD for approximately five (5)
seconds after ignition on. Please note that this will happen only once in any ignition switch cycle. The error
source may be accessed by the procedure described in 'Self Test System Diagnosis', this section.
0 Panel communication check may be initiated by following the instruction in 'Self Test System Diagnosis', this
section.
Nsfe: Displayed error codes are NOT directly related to Jaguar Diagnostic Equipment (JDE) but more detailed fault
related information may be accessed using Portable Diagnostic Unit (PDU).
14.6.2 System Protection
Power to the compressor clutch may be cut should either the engine management or air conditioning control systems
detect certain conditions; these conditions may be caused by Fault or Demand and can be classified thus:
0 Engine coolant overheat,
0 Refrigerant excessive pressure.
0 Refrigerant, insufficient pressure or low charge weight.
0 Speed differential between compressor and crankshaft caused by belt slippage or compressor seizure (indi-
cated by A/C state lamp flashing once per second) - 12 cylinder engine only. This feature, 'lock sensing' is fully
explained
in the EDM.
Demand
0 Engine maximum power requirement
0 Electrical system drain at engine idle.
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Climate Control Systems
14.8 REFRIGERATION CYCLE:
The Compressor draws low pressure, low temperature re- frigerant from the evaporator and by compression, raises re- frigerant temperature and pressure. High pressure, hot
vaporized refrigerant enters the Condenser where it is
cooled by the flow of ambient air.
A change of state occurs
as the refrigerant cools in the condenser and it becomes a
reduced temperature high pressure liquid.
From the condenser the
liquid passes into the Receiver / Drier which has three functions,
a) Storage vessel for varying system refrigerant demand.
b) Filter to remove system contaminants. c) Moisture removal via the dessicant.
With the passage through the
receiver/drier completed the,
still high pressure liquid refrigerant enters the Expansion
Valve where it is metered through a controlled orifice which
has the effect of reducing the pressure and temperature.
The refrigerant, now
in a cold atomized state, flows into the
evaporator and cools the air which is passing through the
matrix.
As heat is absorbed by the refrigerant
it once again changes
state, into a vapour, and returns to the compressor for the
cycle to be repeated (Fig.
1).
There is an automatic safety valve incorporated in the com- pressor which will operate should the system pressure be in
excess of 41 bar. The valve will reseat when the pressure
drops below 27,6 bar.
W Thedivisionof HIGHandLOWsideissimplythesys- tem pressure differential created by the compressor
discharge (pressure), suction (inlet) ports and the
relative inlet and outlet ports
ofthe expansion valve.
This differential is critical to system fault diagnosis
and efficiency checks.
Twelve Cylinder Vehicles only:
Dual pressure switch: This two-function pressure switch
cuts electrical power to the compressor clutch if the system
pressure is outside of the range
of 2 Bar (1st Function) to 30
Bar (2nd Function).
Six Cylinder Vehicles only:
There are two switches incorporated into the high side of the
system which have the following functions:
a) Trinary; This three function pressure switch, cuts electri
-
cal power to the compressor clutch should the system pres- sure not be in a range of 2 bar (1st function) to 30 bar (2nd
function). The switch also provides a ground signal to oper
- ate the appropriate relay (within the 'Stribel,' unit) to ener- gize both engine cooling fans when maximum A/ C cooling
is required. Operation pressure, 20 bar input (3rd function).
b) Pressure Switch Slow Cooling Fans; When the system
pressure is 12 bar, medium A/ C demand, the operation of
this switch connects both engine cooling fans in series to op- erate at half battery voltage and so, half fan speed. 1.
Compressor
2. Condenser
3. Receiver / Drier 4. Expansion Valve
5. Evaporator
6. Pressure switch - Dual type
on 12
cyl & Trinary on 6 cyl
Fig. 1
0
0
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Climate Control Systems
14.10 FAULT DIAGNOSIS
14.10.1 Introduction
It is very important to positively identifythe area of concern before starting a rectification procedure. A little time spent
with your customer to identify the conditions under which a problem occurs will be beneficial. Relevant criteria are:
Weather conditions, ambient temperature, intermittent or continuous fault, airflow fault, temperature control fault, dis
- tribution fault and air inlet problem.
14.10.2 Functional Check
This simple 'first line check' will allow you to ascertain whether the system is operating within its design parameters,
without recourse to (JDE). Please carry out the following, in order.
0 Start engine and attain normal running temperature.
0 Presss AUTO to display selected temperature and illuminate AUTO & AJC state lamps.
0 Rotate FAN to increase or decrease lower speed, verify bar graph representation.
0 Operate AJC to toggle on or off. Because the compressor can be inhibited by the engine management system,
ensure that the engine temperature is normal and that the ambient is above 5O C.
0 Operate RECIRC, state lamp should be lit and the flap behind the blower grille open.
0 Operate distribution buttons in turn, verify correct air distribution and relevant state lamp.
0 Operate DEFROST, check max fans and air to front screen.
0 Cycle TEMPERATURE to 'Hi' and 'Lo' to verify demanded variations and display operation. Note that extremes
will provide max heat or cold independent of in-car temperature.
0 Operate EX to toggle between ambient and control temperatures.
0 Operate HFS and HRW to note timer and mirror operation.
0 Initiate System Self Test to check for, and extract, stored faults should any of the above not perform as stated.
14.10.3 System symptoms
There are five basic symptoms associated with air conditioning fault diagnosis. The following conditions are not in order of priority.
No Cooling
0 Is the electrical circuit to the compressor clutch functional?
0 Is the electrical circuit to the blower motor(s) functional?
0 Slack or broken compressor drive belt.
0 Compressor partially or completely seized.
0 Compressor shaft seal leak.
0 Compressor valve or piston damage (may be indicated by small variation between HIGH &LOW side pressures
relative to engine speed).
0 Broken refrigerant pipe (causing total loss of refrigerant).
0 Leak in system (causing total loss of refrigerant) - possible code 23.
0 Blocked filter in the receiver drier.
0 Evaporator sensor disconnected - possible code 13.
0 Pressure switch faulty - possible code 23.
X300 VSM Issue 1 August 1994

Climate Control Systems
Action
Simultaneously hold AUTO and RECIRC - Switch
ignition to ON
Press AUTO
Press FACE
Simultaneously press FACE and HRW
Press
RECIRC (Press FAN to skip actuator check)
Press FAN
14.11 SYSTEM SE1 F-TEST
14.11. I Interrogation Procedure via the Control Panel
Result
Display element check
Any stored fault NUMERIC code
(If ZERO appears there are
no stored codes)
Scroll through stored faults (maximum of
5)
Clear stored fault codes (may need to be repeated for each
fault)
Initiate actuator check (Actuator codes
20 through 27*)
Exit error check mode
Fault Code
0
11
12
13
14
15
21
22
0
23
14.1 1.2 Control Panel Fault Code Key
Item Description
Normal Operation No
fault codes present, wait 30 seconds for system self-
check.
Motorized In
-car Aspirator Open /short in sensor circuit. Panel fault codes are not stored
for motorized in
-car aspirator motor failure.
Ambient Temperature Sensor Open
/ short circuits.
Evaporator Temperature Sensor Open
/ short circuits.
Water Temperature Input Instrument pack output.
Heater Matrix Temperature Sensor Open
/ short circuits.
Solar Sensor Open
/ short circuits.
Compressor Lock Signal
- 12 cylin- Open /short circuits. Low gas charge, low compressor oil,
der and supercharged
6 cylinder loose belt.
engines only.
Refrigerant Pressure Switch Open /short circuits. Low gas charge*
31
32
33
34
35
36 0
I 24 1 Face Vent Demand Potentiometer. 1 Open / short circuits
LH Fresh
/ Recirc. Potentiometer
RH Fresh / Recirc. Potentiometer
cool ~i~ by-pass potentiometer
Defrost Vent Potentiometer
Centre Vent Potentiometer
Foot Vent Potentiometer Open
/short circuit
in potentiometer. feed.
w: and log further faults. Cycling the ignition two or three times
after rectification of the fault will cure this.
In certain circumstances, the motor can over-travel
43
44
I Defrost Vent Motor
I Cool Air by-pass Motor
I 41 I LH Fresh / Recirc. Motor I
Check for short / open circuits in motor drive lines. Motor flap
sticking
/ jammed.
1 42 I RH Fresh / Recirc. Motor I
1 45 I Centre Vent Motor I
46 I Foot Vent Motor
w: In ambient temperatures below Oo C, the system may log fault code 23 because the low ambient causes a tem-
porary low gas pressure. Where the ambient temperature rise above 40" C, and if the engine is close to over- heating, feed to the compressor clutch may be cut and code 23 registered.*
X300 VSM 17 Issue 1 August 1994

Climate Control Systems
No heat
One vent failing to open
/ close
Poor airflow
14.11.3 Associated Faults
Other symptoms that may exist without storing fault codes:
Airlock in system.
Electric water
pump inoperative
Coolant flow valve stuck closed
Faulty engine coolant thermostat
Broken linkage.
Blower motors
- incorrect operation
14.11.4 Panel Communication Check
Action Result
Panel communication
with FACE, FOOT & FACE, FOOT,
SCREEN
& FOOT, DEFROST, RECIRC lines checked - State lamps will illuminate if all is OK. Unlit state lamp
means continuity fault for that specific link. See EDM
for
full check.
0
0
0
Issue 1 August 1994 18 X300 VSM

Climate Control Systems
14.13 SYSTEM CHECKING WITH MANIFOLD GAUGE Sm
14.13.1 Evacuating the Manifold Gauge Set
Attach the centre (service) hose to a vacuum pump and start the pump. Open fully both high anddow valves and allow
the vacuum to remove air and moisture from the manifold set for at least five minutes.
Turn the vacuum pump off and isolate it from the centre service hose but do not open the hose to atmosphere.
CAUTION: It is imperative that the vacuum pump is not subjected to a positive pressure of any degree. Therefore
the pump must be frtted with an isolation valve at the centre (service hose) connection and this valve
must be closed before the pump is switched off. This operation replaces the 'purge' procedure used on
previous systems. Observe the manufacturefs recommendation with regard to vacuum pump oil
changes.
14.13.2 Connecting the Manifold Gauge Set
CAUTION: Only use hoses with connectors which are dedicated to HFC 134A charge ports.
Attachment of the hose quick release connectors to the high and low side system ports is straightfotward, provided
that the high and low valves are closed and the system is NOT operational.
Assessment of system operating efficiency and fault classification may be achieved by using the facilities on your
Re- covery / Recharging / Recycling station, follow the manufacturers instructions implicitly and observe all safety con- siderations.
WARNING: UNDER NO CIRCUMSTANCES SHOULD THE CONNECTIONS BE MADE WITH THE SYSTEM IN
OPERATION OR THE VALVES OPEN. SHOULD THE VALVES BE OPEN AND A VACUUM PUMP OR
REFRIGERANT CONTAINER ATTACHED, AN EXPLOSION COULD OCCUR AS A RESULT OF HIGH
PRESSURE REFRIGERANT BEING FORCED BACK INTO THE VACUUM PUMP
OR CONTAINER.
14.13.3 Stabilizing the System
Accurate test gauge data will only be attained if the system temperatures and pressures are stabilized.
Ensure that equipment and hoses cannot come into contact with engine moving parts or sources of heat.
It is recommended that a free standing air mover is placed in front of the vehicle to provide air flow through the con- denser / cooling system, see illustration below.
Start the engine, allow
it to attain normal working temperature and set at fast idle (typically 1200 to 1500 rpm). Select full air conditioning performance.
With all temperatures and pressures stable, or displaying symptoms of faults; begin relevant test procedures.
Fig.
1
Issue 1 August 1994 20 X300 VSM

Climate Control Systems
High Side Gauge
Normal
@ 14.16 SYSTEM PRESSURE FAULT CLASSIFICATION
This table should be used in conjunction with the graphical representations of 'High side' pressure / ambient tempera- ture and 'Low side' pressure / evaporator temperature, this section.
Fault Cause
Discharge air initially cool then Moisture in system
warms up
1 Low Normal
Low
Low
Low
Low
I Low
As above As above
Discharge air slightly cool HFC
134A charge
low
Discharge air warm HFC
134A charge very low
Discharge air slightly cool or frost Expansion valve
stuck closed
build up
at expansion valve
Discharge air slightly cool, sweat
- Restriction in High side of
ing or frost
after point of restriction system
I
Low
High
High
I
Compressor noisy Defective compressor
reed valve
Discharge air warm and high side HFC
134A charge
high or
pipes hot inefficient
condenser cooling
dueto
air flow blockage or engine cooling
fans not working
Expansion valve stuck open
Discharge air warm
Sweating or frost
at evaporator
If erratic or unusual gauge movements occur, check the equipment against a known (calibrated) manifold
gauge
set. ~ ~~~
X300 VSM 23 Issue 1 August 1994