cruise control JAGUAR X308 1998 2.G Workshop Manual

Hydrau
lic Brake Actuation - Brake Pedal and Bracket, Brake Booster and
Brake Master Cylinder
Re mo
val and Installation
Remova

l
• C
A
UTIONS:
Replacement of nuts and bolts: Various thread-locking de vices are used on nuts and bolts throughout the vehicle.
These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
Remove brake fluid spilla ge immediately from paint work, with clean water.
1. Position vehi cl
e on a four-post lift.
2. Open engine compartment and fit paint work protection covers
to fenders.
3. Disconnect battery ground cable (IMPORTANT, refer to
operation 86.15.19 for fu rther information).
4. Remove engine compartment rear cover. Refer to operation
76.11.35.

5. Reposi
tion the mounting bracket of the cruise control vacuum-
valves for access (if installed).
R e
move screws.
Reposition bracket.


6. Disc
onnect low-level warning connector from master cylinder.
7. Disconnect vacuum pipe from brake booster.
1. Disconnect pipe.
2. Remove and discard seal.

8. Conne ct
low-level warning connector to master cylinder.

9. Inst al
l cruise control vacuum-valves, mounting bracket.
Install and tigh
ten bolts.

10 . Conne
ct stop lamp switch connector.
Conne
ct
connector.
Re
posi
tion carpet.
11. Connect battery ground cable (IMPORTANT, see operation
86.15.15 for further information).
12. Bleed brake system. See operation 70.25.03.
13. Install engine compartment rear cover. Refer to operation
76.11.35.
14. Remove paint-work protection covers and close engine
compartment.

15 . Conne
ct battery ground cable (I
MPORTANT, refer to operation
86.15.19 for further information).

The brake
control modulator comprises:
a A

BS/TCCM
a h

ydraulic control unit,
an electrically driven hydrau

lic pump,
two low pressure accumulato

rs and damping chambers.
ABS/TCCM


The AB
S/TCCM is integrated with the hydrau
lic control unit. It houses the solenoids that operate the hydraulic control unit's
input and return valves; the valve stems locate into the ABS/TCCM's solenoids. There is no electrical connection between
the ABS/TCCM and the hydraulic control unit.
The ABS/TCCM constantly monitors the brake electronic system by passing self-checking electrical pulses around the circuit.
The self check procedures carried-out by the ABS/TCCM are listed below:
1. 1. Monitoring of the operating voltage: the control mo dule will shut-down should the voltages not be
(approximately) in the range of 9 to 19V.
2. 2. The pump is monitored for volt age supply and voltage feedback.
3. 3. Monitoring for disturbance, where a failure may be caus ed by external radio frequency interference, internal
leakage current, defective valve transistor or a faulty valve.
4. 4. Internal controller failure, de tected by a RAM and ROM test.
5. 5. The controller area network (CAN) micr o-controller checks for correct operation of the communication network
and performs a RAM self-check.
CAUTION: Disconnection of ABS/TCCM connectors may introduce other fault codes. Following rectification and
reconnection, ensure that no induced codes exist.
5.
Signals processed by the ABS/TCCM are also sent to the CAN for vehicle use, such as the instrument cluster speed display,
cruise control and stability/traction control.
Hydraulic Control Unit

Control of
the fluid pressure to
the front and rear brakes is by means of the valves contained in the hydraulic control unit.
The valves are operated by solenoids housed in the ABS/TCCM.
Hydraulic Pump
The
hydraulic pump is integrated
with the hydraulic control unit.


Bra
ke Control Modulator

E
ngine Management System Components
Electronic Throt
tle
The
electronic throttle assembly, in resp
onse to signals from both the driver and the ECM, adjusts idle speed, sets the
throttle valve to the position requested by the driver's accelerator / throttle pedal, cruise and traction control, power
limitation and catalyst warm-up.
Mass
Air Flow Meter
The sensor i
s located in the air flow mete
r assembly and outputs an analogue voltag e to the ECM. This sensor measures air
flow into the engine inlet system and is calibrated to measure kg / hour.
In
take Air Temperature
Th
e intake air temperature sensor is loca
ted in the air flow meter assembly and outputs an analogue voltage to the ECM.
The ECM will substitute a default value eq ual to 50°C should this sensor fail.
Fuel Injectors
The eigh
t bottom fed fuel injectors are located in the fuel rails. Th
e fuel injectors are electromagnetic solenoid valves
controlled by the ECM. The pulse time for the injector combined with the fuel pr essure determines the volume of fuel
injected to the manifold.
Fue
l Delivery
The fu
el pump provides fuel to the fuel rail where the circulat
ing pressure is controlled by a pressure regulator valve; excess
fuel is returned to the fuel tank.
The pressure regulator valve is controlled by manifold depression so that fuel delivery pressure is maintained at
approximately 3 bar above manifold pressure.
Fuel Pump
Relay
The ECM controls thi

s component for normal
engine running. The security system may disable this relay via communication
with the ECM.
Fuel Lev
el Sensing
The tank fuel

is measured by the fuel le
vel sensor . This signal is used by the ECM as an in put to certain diagnostics.
Eva
porative Valve
Excess vapour

formed in the fuel tank is
absorbed into the evaporative emission pu rge control canister. While the engine is
running, the fuel absorbed in the canister is gradually purged back into the engine. The rate of purging is governed by
engine operating conditions and vapour concentration level. Operating conditions which affect the purge rate are:
2—Purge
valve
3—Engine

torque reduction
4—E

lectronic throttle assembly
5—Coo

ling fans
6—Ignition amplifier driver
7—Engine overspeed
8—Cli

mate control compressor clutch
9—O

BDII information (J1962, CAN, ISO)

10—F
uel pump relay
11—Heat

ed oxygen sensor
12—Vari

able valve timing
13—MIL sw

itching



ECM Out
puts
It

em
Par
t Number
De
scription
1—Exhaus

t gas recirculation

Default mode Definitions

MECH
ANICAL LIMP-HOME MODE:

No el
ectronic throttle operation (mechanical
operation for last quarter of pedal travel)
M
aximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine
speed restricted to 3000
rpm maximum, by fuel cut-off
Hi
gh idle speed (1200 rpm approx.)
Misfire

at idle, due to cylinder cut as a means of control
ling idle speed (the misfire will switch cylinders, as the
strategy varies th e cylinder cut)
Cruise (speed) contr
ol inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
El
ectronic throttle operation, limited to maximum 25°
Cruise (speed) contr

ol inhibited
• NOTE: The throttle oper ation uses the same map as for reverse gear.
ENGINE SPEED LIMIT:
Engine
runs normally, up to 3000 rpm
Engine

speed restricted to 3000
rpm maximum, by fuel cut-off
Cruise (speed) contr
ol inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contr
ol inhibited
R

everse throttle pr
ogression engaged at second occurrence of DTC flagging
Diagnostic Trouble Code (D
TC) index
DT
C
Cond
ition
P
ossible Causes
Acti
on
P0171Right-hand cylinders combustion too

leanAir
intake leak between MAF
sensor and throttle
F
uel filter system blockage
F

uel injector blockage
F

uel pressure regulator failure (low

fuel pressure)
Low f
uel pump output
H0

2S harness wiring fault
E

xhaust leak (before catalyst)
ECM receivi

ng incorrect signal from

one or more of the following
sensors - ECT, MAF, IAT, TP.
Fo
r intake system,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
F
or fuel filter,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors. Check the
fuel pressure regu lator. Check fuel
pressure. For HO2S circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
F
or exhaust information,
REFER to Section 309
-00
Exhaust
Sy

stem
.
For se
nsor circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P0172Right-hand cylinders combustion too

ri
ch
Engine
misfire
Bl

ocked air filter
F

uel system return blockage
Leak

ing fuel injector(s)
F

uel pressure regulator failure
(high fuel pressure)
ECM receivi
ng incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
Chec
k for 'engine misfire detected'
DTCs. Check the air filter element,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
Chec
k the fuel lines,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors,
REFER to Fuel Injectors
- in t
his
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
.
Check the fuel
pressure,

Default mode Definitions
MECHANIC
AL LIMP-HOME MODE:

No elec
tronic throttle operation (mechanical
operation for last quarter of pedal travel)
Ma
ximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine speed restri
cted to 3000
rpm maximum, by fuel cut-off
High i
dle speed (1200 rpm approx.)
Misfire
at idle, due
to cylinder cut as a means of control
ling idle speed (the misfire will switch cylinders, as the
strategy varies th e cylinder cut)
Cruise (speed) contr o
l inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
Elec
tronic throttle operation, limited to maximum 25°
Cruise (speed) contr
o
l inhibited
• NOTE: The throttle oper ation uses the same map as for reverse gear.
ENGINE SPEED LIMIT:
Engine runs
normally, up to 3000 rpm.
Engine
speed restri
cted to 3000 rp
m maximum, by fuel cut-off.
Cruise (speed) contr o
l inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contro
l inhibited
Re

verse throttle pr
ogression engaged at second occurrence of DTC flagging
AmberRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P01 16,
P0117, P0118, P0125
Ambe
rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P01 01,
P0102, P0103, P0104
Ambe
rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P03 00,
P0301, P0302, P0303, P0304, P0305,

P0306, P0307, P0308, P1313, P1314
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P03 27,
P0328, P0332, P0333, P1648
Ambe
rRestri
cted
Performance
R e
verse throttle pr
ogression enabled
P1474
AmberRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P1230
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P1671
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to

3000 rpm)
P11 12,
P1113
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1601 (SC on
ly)
AmberRestri
cted
Performance
Gearbox defau l
t to 4th gear
P16
05 (
NA only)
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P0702
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1795
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1796
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1797
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1605
Ambe
rNoneGearbox defau l
t to 4th gear
P0705 (SC on
ly)
AmberNoneGearbox defau l
t to 4th gear
P0706
Ambe
rNoneGearbox defau l
t to 4th gear
P1720

2.2. Cruise
3. 3. Mechanica l
guard
4. 4. Fixed idle
5. 5. Redundancy
6. 6. Full authority
7. 7. Engine shut-down
Normal mode occurs when the EC M uses the mechanical and monitoring arrangem ent of the throttle valve to control throttle
opening. The ECM does not permit driver demand to be exceeded but it can be restricted to allow for such features as
stability / traction control, or engine power limitation.
The ECM determines engine idle speed by controlling the throttle valve motor to vary the blade angle between the non-
adjustable preset limits of the mechanic al guard and the throttle valve motor.
Cruise mode is engaged as a result of the ECM calculating and controlling the required throttle valve opening via the
vacuum system. When the driver releases the throttle pedal, the input shaft disengages from the mechanical guard or the
vacuum actuator pulls the guard away from th e throttle valve. The throttle pedal will feel light should it be pushed again to
accelerate (pressing the pedal further will re-engage the input shaft with the mechanical guard and restore normal feel).
The ECM utilizes sensors to monitor the relative positions of the mechanical guard and throttle valve and adjusts them to
maintain the set cruise speed.
Mechanical guard mode permits full mechanical operation of the throttle if the ECM detects that a problem has been
encountered with the throttle valve position sensor, dc motor, associated harnesses / connecto rs or the ECM.
Fixed idle mode occurs when any two of the three sensors (two input shaft sensors and the mechanical guard sensor) fail.
The ECM will assume values which represent a blade angl e of approximately 2,5° and 1200 rpm (unloaded) maximum
engine speed.
Redundancy mode occurs when any one of the three sensors (two input shaft sensors and the mechanical guard sensor)
fails. The operational pair will be deemed to be safe to co ntinue without intervention, but cruise will be inhibited.
Full authority mode is invoked when a mech anical guard failure occurs which indicates that the guard is stuck fully open.
The red warning lamp will be lit and road speed will be li mited to 120 kph.
Engine shut-down mode will occur followin g multiple failures, such as mechanical guard mode following full authority mode
(or vice versa) or the throttle blade sticks.
Intake Elbow

The intake elbow directs the metered airflow from the electronic throttle to the intake manifold. Stub pipes on both sides of

the
intake elbow provide connections for vacuum actuators and are also used to redirect emissions into the engine.
On the right-hand side of the elbow a la rge diameter pipe connects to the brake servo. The smaller pipe provides a vacuum
feed to the fuel rail pressure regulator and throttle cruise control system. On the le ft-hand side of the elbow the front pipe
supplies vacuum control for the evaporative emissions system valves.
Emissions from the engine part load breather (bank 2) and pu rged fuel vapor from the EVAP valve are drawn via a common
T piece into the left-hand side of the intake elbow. Re-cir culated exhaust gas enters the intake elbow via the EGR valve
which is mounted directly on the rear of the elbow : where the EGR system is not used, a blanking plate is fitted.
The fuel system, throttle and emission control system s are described more fully in the relevant sections.
Intake Manifold

Filtered air from the vehicle's intake ducting is metered by th e electronic throttle and distributed to the two cylinder banks
via an integral intake manifold.
The intake manifold is manufactured in plastic with integral plastic fuel rails and metal-thread inserts; the very smooth
internal surfaces give excellent air flow.
Individual ducts lead off a central chamber to the inlet valves of each cylinder.
Silicon-rubber gaskets, loca ted in channels in the intake manifold, seal th e joints between the ducts and the cylinder heads.
Engine Ventilation

The e
ngine is ventilated through two brea
thers; a part-load breather and a full-load breather, one on each camshaft cover.
The outlet hose for the part-load breather is connected between the bank 2 camshaft cover and the intake elbow. The full-
load outlet hose is connected from the bank 1 camshaft cover to the intake duct between the MAF sensor assembly and the
throttle body.
Constructed in plastic, the hoses incorporate O-ring seal s and quick-release connectors; refer to Section 303-01.
I
ntake Air Distribution and Filtering - Supercharged Vehicles
Ai
r is supplied to the supercharger via an
intake cleaner/duct, throttle assembly and intake elbow which are similar to those
used for normally aspirated engines. The su percharger delivers pressurized air to two separate charge air cooler units, each
unit being mounted on the cy linder bank which it supplies. Pr essurized cooled air is fed from the charge air coolers directly
into each inlet port.

The intake elbow di
rects the metered airflow from the electronic throttle outlet (und
erside of the throttle body) into the
intake of the supercharger.
The supercharger by-pass valve assembly is bolted to the intake elbow. The butterfly valve inside the assembly is opened
by a diaphragm actuator operated by vacu um feed from the elbow. At closed or partially open throttle positions, the
butterfly valve opens, allowing th e airflow from the two charge air cooler inlets to be directed back to the supercharger inlet .
This action inhibits the supercharging e ffect and reduces engine torque to non supercharged levels. Progressive opening of
the throttle causes the by-pass valve to gradually close.
On the right-hand side of the elbow a la rge diameter pipe connects to the brake servo. On the left-hand side the smaller
pipe supplies vacuum control for the evaporative emissions system valves.
Emissions from the engine part load breather (bank 1) and pu rged fuel vapor from the EVAP valve are drawn via a common
T piece into the left-hand side of the intake elbow. Re-cir culated exhaust gas enters the intake elbow via the EGR valve
which is mounted directly on the rear of the elbow. Where the EGR system is not used, a blanking plate is fitted.
The fuel system and emission control systems are described more fully in the relevant sections.
Fuel Pressure Regula
tion and
Cruise Control Vacuum Feed
The inlet v
acuum feed fo
r the fuel rail pressure regula tor and the cruise control system is taken from the supercharger
outlet duct. The feed pipe is located below the large charge air cooler coolant filler plug.
Superchar
ger
and associated components
Inta
ke Elbow and Bypass

Fue
l pump
Engine coolan

t temperature

(ECT) sensor
Blocked part-load breather (
service action S474)
Injec

tor leak
Emiss
ions
.
Check bull
etins for throttle cleaning procedure.
Check fuel pressure. For ECT sensor circuit tests,
GO to Pinpoint Test C.
. Refer to Servi
ce action
S474 for part-load breather procedure. For
injector leak test, Refer to technical service bulletin 303-39.
D
ifficult to start after hot
soak (vehicle standing
after engine has reached operating temperature)
Roc
hester valve
Thr

ottle contaminated
Purge

valve
Fue

l pump
Engine coolan

t temperature

(ECT) sensor
Blocked part-load breather (
service action S474)
Injec

tor leak
Engine cranks too
fa
st/slow
Batt
ery
Starter relay Harness Cyl

inder compression loss
(NA short term only. Refer to technical service bulletin; 303-39)
R
efer to service action
S491
F
or battery information,
REFER to Section 414
-0
1 Battery, Mounting and

Cables.
F
or starting system.
REFER to Section 303
-06 Sta
rting System
.
R
efer to technical servic
e bulletins and service
actions.
Engine

stalls
Engine st
alls soon after
start
F
uel pump relay
ECM relay Thr

ottle contaminated
CMP/CKP sen

sor
synchronization malfunction
Harness Fue
l pump
MAF

sensor malfunction
Engine coolan

t temperature

(ECT) sensor
Fue
l lines
Air leakage


F

uel pressure regulator
Check r
elay dates. Chec
k for DTCs. For fuel
pump relay tests,
REFER to Section 303
-0
4 Fuel Charging and
Controls.
F
or ECM relay tests, GO to Pinpoint Test
AD.
.
Check bull
etins for throttle cleaning procedure.
For CMP sensor circuit test s, GO to Pinpoint Test
C.
, for
CKP sensor circuit tests, GO to Pinpoint
Test N.
. Check fuel
pressure. For MAF sensor
circuit tests, GO to Pinpoint Test A.
. For EC
T
sensor tests, GO to Pinpoint Test C.
. F
or fuel
system,
REFER to Section 303
-0
4 Fuel Charging and
Controls.
and
REF
ER to Section 310
-0
1 Fuel Tank and Lines
. F

or intake system information,
REFER to Section 303
-1
2 Intake Air Distribution

and F
iltering
.
Engine

stalls on overrun
Thr
ottle contaminated
ECM relay F

uel pump relay
CMP/CKP sen

sor
synchronization malfunction
Check bull
etins for throttle cleaning procedure.
Check relay dates. For ECM relay tests, GO to Pinpoint Test AD.
. F
or fuel pump relay tests,

REFER to Section 303
-0
4 Fuel Charging and
Controls.
F
or CMP sensor circuit test
s, GO to Pinpoint Test
O.
, for
CKP sensor circuit tests, GO to Pinpoint
Test N.
.
E
ngine stalls at steady
speed, with or without cruise enabled
Thr
ottle contaminated
ECM relay F

uel pump relay
CMP/CKP sen

sor
synchronization malfunction
Harness Blocked part-load breather
(
service action S474)
Check bull
etins for throttle cleaning procedure.
Check relay dates. For EC M relay circuit tests,GO
to Pinpoint Test AD.
. F
or fuel pump relay circuit

tests,
REFER to Section 303
-0
4 Fuel Charging and
Controls.
F
or CMP sensor circuit test
s,GO to Pinpoint Test
O.
, for
CKP sensor circuit tests,GO to Pinpoint
Test N.
. Che
ck service actions.
Engine st

alls when
maneuvering
ECM relay F
uel pump relay
CMP/CKP sen

sor
synchronization malfunction
Check r
elay dates. For EC
M relay circuit tests,GO
to Pinpoint Test AD.
. F
or fuel pump relay circuit

tests,
REFER to Section 303
-0
4 Fuel Charging and
Controls.
F
or CMP sensor circuit test
s,GO to Pinpoint Test
O.
, for
CKP sensor circuit tests,GO to Pinpoint
Test N.
.