Fuse box JAGUAR X308 1998 2.G User Guide

Measure t
he resistance
between BT15 and GROUND.
2
Is the res
istance greater than 5 ohms?
Yes GO to B2
.
No
GO to B3
.
B2: CHECK THE FUEL
LEVEL SENSOR REFERE
NCE GROUND CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the instrument cluster electrical connector, FC25.
1
Meas
ure t
he resistance between FC25, pin 14 (RW) and BT15 (RW).
2
Is the res

istance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to B3
.
B3: CHECK THE FUEL
LEVEL SENSOR (EMPTY)
Di
sc
onnect the fuel level sensor electrical connectors, BT14 and BT15.
1
Empty the fuel
tank. 2
Measure t
he resistance between the
fuel level sensor connections.
3
Is t
he resistance 900 ohms?
Yes GO to B4
.
No
INST
ALL a new fuel level sensor.
REFER to Section 310
-0 1
Fuel Tank and Lines
.
CLEAR t h
e DTC. TEST the system for normal operation.
B4:
CHECK
THE FUEL LEVEL SENSOR (FULL)
Fi
ll
the fuel tank.
1
Meas
ure t
he resistance between the
fuel level sensor connections.
2
Is
the resistance 80 ohms?
Yes GO to B5
.
No
INST
ALL a new fuel level sensor.
REFER to Section 310
-0 1
Fuel Tank and Lines
.
CLEAR t h
e DTC. TEST the system for normal operation.
B
5
: CHECK THE FUEL LEVEL SENSOR SIGNAL WIRE FOR HIGH RESISTANCE
Di
sc
onnect the instrument cluster electrical connector, FC25.
1
Meas
ure t
he resistance between FC25, pin 13 (BW) and BT14 (BW).
2
Is th
e res
istance greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No INSTALL a new instrument cluster.
REFER to Section 413
-01
Instrume
nt Cluster
.
CLEAR t h
e DTC. TEST the system for normal operation.
P
INPOINT TEST C : DTC P1646; FU
EL PUMP 2 (SC) RELAY MALFUNCTION
•
NO
TE: This DTC applies only to the
supercharged system fuel pump 2.
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
C
1
: CHECK THE FUEL PUMP 2 RELAY POWER SUPPLY
R
e
move the fuel pump 2 relay.
1
Turn the ignition swi
t
ch to the
ON position.
2
Meas
ure t
he voltage between the
relay base, pin 01 and GROUND.
3
Is the volt
age less than 10 volts?
Yes REPAIR the circuit between the rela y base, pin 01 and battery. This circuit includes the trunk fuse
box, the ignition positive relay, and the high power protection module. For additional information,
refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
No GO to C2
.

C2: CHECK THE FUEL
PUMP 2 RELAY TO ECM CIRCUIT
Di

sconnect the battery negative terminal.
1

D
isconnect the ECM electrical connector, EM13.
2

Meas
ure the resistance between the rela
y base, pin 02 and EM13, pin 09 (KB).
3

Is th
e resistance greater than 5 ohms?
Yes REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the

DTC. TEST the system for normal operation.
No INSTALL a new fuel pump 2 relay. CLEAR the DT C. TEST the system for normal operation.
P
INPOINT TEST D : CHECK THE FUEL PRESSURE REGULATOR FUNCTION
CAUTI
ON: Do not run the engine for more than
30 seconds with the vacuum hose disconnected.
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
D

1: CHECK FOR FUEL PRESSURE CHANGE
WHEN THE REGULATOR IS DISCONNECTED
Connect a
fuel pressure gauge set,
REFER to Section 310
-00
Fuel System
-

General Informati
on
. 1

St
art the engine.
2

N
ote the fuel pressure readin
g with the fuel pressure regu lator vacuum hose connected.
3

Di
sconnect the fuel pressu
re regulator vacuum hose.
4

N
ote the new reading.
5

Doe
s the fuel pressure increase when the hose is disconnected?
Yes Check for DTCs. Carry out the pinpoint tests indicated.
No INSTALL a new fuel presssure regulator. TEST the system for normal operation.
P
INPOINT TEST E : DTC P1230;
FUEL PUMP RELAY MALFUNCTION
•
NOTE: This DTC applies only to the N/A system si
ngle fuel pump, and the S/C system fuel pump 1
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
E1

: CHECK THE FUEL PUMP
RELAY BATTERY SUPPLY
R
emove the fuel pump relay.
1

Meas
ure the voltage between the
relay base, pin 03 and GROUND.
2

Is th
e voltage less than 10 volts?
Yes REPAIR the circuit between the rela y base, pin 03 and the battery power bus. This circuit includes the
trunk fuse box and the high power protection module . For additional information, refer to the wiring
diagrams. CLEAR the DTC. TEST th e system for normal operation.
No GO to E2
.
E2
: CHECK THE FUEL PUMP RELAY IGNITION SWITCHED SUPPLY
Turn the ignition swi

tch to the
ON position.
1

Meas
ure the voltage between the
relay base, pin 01 and GROUND.
2

Is th
e voltage less than 10 volts?
Yes REPAIR the circuit between the rela y base, pin 01 and battery. This circuit includes the trunk fuse box,

fuse 16 of the left-hand fuse box, the ignition po
sitive relay and the high power protection module.
For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal
operation.
No GO to E3
.
E3
: CHECK THE FUEL PUMP RELAY TO
ECM CIRCUIT FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1

D
isconnect the ECM electrical connector, EM83.
2

Meas
ure the resistance between EM83, pi
n 04 (WR) and the relay base, pin 02.
3

Is th
e resistance greater than 5 ohms?
Yes REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the
DTC. TEST the system for normal operation.
No

INSTALL a new fuel pump relay. CLEAR the DTC. TEST the system for normal operation. If the DTC is
repeated, contact dealer technical support for advice on possible ECM failure.

The il
lustration above is a simplified expl
anation of how the starting system operates in conjunction with the Body Processor
Module (BPM) and the Engine Control Module (ECM).
Refer to the Starting Circuit Diagram in the Electrical Guide.
I g
nition Switch to ON Position
W
h
en the ignition key is set to the normal run position, the following sequence occurs:
The
is
olation relay in each fusebox is
energised to supply battery power to the fuses and associated circuits.
The BPM 'IGN
ON' terminal
is taken to 0V by the ignition switch.
The BPM
checks that various parameters are correct e.g. -
inertia switch is in the active condition - transmission is in
PARK - security system has been correctly disabled.
It e
m
De
scr
iption
1Batt
ery
2To Re ar
Fusebox
3Hi
gh Power Pr
otection Module
4To Front
Fu
seboxes
5Starter Re
lay
6Body Processor M
odule (BPM)
7Engine
C
ontrol Module (ECM)
8Ignition Switch
9CRANK Signal
10Ignition ON Signal
11Inertia Switch
12St
arte
r Motor and Solenoid
Starting System Operation

The BPM
'CRANK SELECTED' terminal is ta
ken to 0V by the ignition switch.
The BPM
'O/P ENGINE CRANK' terminal pr
ovides a path to ground for the starte r relay coil, via Fuse 5 (10A) located
in the engine compartment front fusebo x. This path to ground also indicates to the ECM 'I/P ENGINE CRANK'
terminal, by taking it to 0V, that the engine has been requested to crank.
Wi
th the starter relay contacts closed,
power via Fuse 3 (25A) in the engine compartment rear fusebox, is supplied
to the pull-in winding of the starter solenoid.
The s
olenoid main contacts close and are held
closed by the solenoid hold-in winding.
Battery power is supplied
to
the starter motor through the solenoid main contacts, direct from the battery and the
High Power Protection Module.
Starter
Motor Internal Connections

Re
fer to the Starting Circuit Diagram in the Electrical
Guide for the actual layout and connection details.
The starter motor and solenoid in the previous figure are shown diagrammaticall y to indicate simply, the electrical circuit
and various connections.


It
em
De
scription
1Batt

ery
2Ignition Switch
3So

lenoid Contacts
4So

lenoid Pull-In Winding
5So

lenoid Hold-In Winding
6So

lenoid
7St

arter Motor Main Body
I
gnition Switch at CRANK Position
W
hen the ignition key is set to the crank position, the following sequence occurs:

Starting System - Starting System
Diagn
osis and Testing
I
n
spection and Verification
W
A
RNING: Make sure
the vehicle is in NEUTRAL or PARK for vehicles with au tomatic transmission, NEUTRAL for
vehicles with manual transmissi on, and apply the parking brake. Failure to foll ow this instruction may result in personal
injury.
1. 1. Verify the customer concern.
2. 2. Visually inspect for obvious signs of mechanical or electrical damage, correct fitment, etc.
Vi
sual Inspection Chart
3.
3. If an obvi
ous cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
4. 4. If the concern is not visually evident, refer to the Diagnostic trouble code (DTC) index.
CAUTION: When probing connectors to take measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00. Failure to follow this in struction may result in damage to the vehicle.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
MechanicalElectrical
Starte
r motor
Flywheel

ring gear
Engine
s
eized
Batter
y condition, state of charge
Starte

r motor
F
u
se 3 of the EMS fuse box
High
power protec ti
on module
Starter relay Ignition switc
h

W
i
ring harness(es)
Damaged, loose or corroded connector
s

Body processor module (B
PM)

Engine
C
ontrol Module (ECM)
Sy
m
ptom
(
gene r
al)
Sy
m
ptom
(specific)
Possib l
e source
Acti
o
n
No
n
-Start
Engine does
not
crankEngine s
iezed
Batt
ery and
/or
cables
Inhibitor circuit St arte
r motor
Starter relay Ignition switc
h


ECM relay Body processor
modu le
Check that
the engine turns. Check the battery condition and state

of charge. For starter motor and ca ble tests,GO to Pinpoint Test A.
. For ECM relay
tests,
REFER to Section 303
-14
Electronic Engine Controls
.
Engine
c
ranks
too fast/slow
Batt ery and
/or
cables
St arte
r motor
Cy
linder
com
pression
Check the battery con
dition
and st
ate of charge. For starter motor
and cable tests,GO to Pinpoint Test A.
. Chec
k compressions.

It e
m
Par
t
Number
De
scr
iption
1—Engine
control module (E
CM)
2—Ignition control
modules (1 and 2)
3—Igniti
on coils - 1A (bank 1, coil 1 only drawn)
4—Spark
plug - 1
A (bank 1, plug 1 only drawn)
5—Igni
ti
on coils supply relay
6—Engine

management system fuse-box
Ci
rcui
t Diagram,
Ignition System

RE
PAIR the circuit between the EGR valve and battery. This circuit includes the EMS relay and the
EMS fuse box. For additional info rmation, refer to the wiring diagrams. CLEAR the DTC. TEST the
system for normal operation.
No GO to A2
.
A2: CHECK THE EGR VALVE COIL WIND
INGS FOR CONTINUITY
Meas
ure t
he resistance between pins 04 and 06 of the EGR valve.
1
Meas
ure t
he resistance between pins 01 and 03 of the EGR valve.
2
Is either resi
stance
greater
than 80 ohms?
Yes INSTALL a new EGR valve.
REFER to Exhaust Gas Recirculation (EGR) Valve
- in thi
s section.
CLEAR the DTC. TEST the syst em for normal operation.
No GO to A3
.
A3: CHECK THE EGR VALVE COIL WINDINGS TO
POWER SUPPLY CIRCUIT FOR CONTINUITY
Meas
ure t
he resistance between pins 02 and 03 of the EGR valve.
1
Meas
ure t
he resistance between pins 05 and 06 of the EGR valve.
2
Is either resi
stance greater
than 80 ohms?
Yes INSTALL a new EGR valve.
REFER to Exhaust Gas Recirculation (EGR) Valve
- in thi
s section.
CLEAR the DTC. TEST the syst em for normal operation.
No GO to A4
.
A4: CHECK THE EGR VALVE T
O ECM
CIRCUITS FOR HIGH RESISTANCE
Disc
onnect the battery negative terminal.
Vehicles with AJ26 engine:
D i
sconnect the ECM electrical connector, EM12
Meas
ure t
he resistance between the following:
PI34, pin
0
4 (YU) and EM12, pin 01 (YU)
PI34,
pi
n 01 (YG) and EM12, pin 02 (YG)
PI34, pin
0
6 (YN) and EM12, pin 03 (YN)
PI34,
pi
n 03 (YR) and EM12, pin 04 (YR)
Vehicles with AJ27 engine:
D i
sconnect the ECM electrical connector, EM85
Meas
ure t
he resistance between the following:
PI34, pin
0
4 (YU) and EM85, pin 03 (YU)
PI34, pi

n 01 (YG) and EM85, pin 04 (YG)
PI34, pi

n 06 (YR) and EM85, pin 09 (YR)
PI34, pi

n 03 (YR) and EM85, pin 10 (YR)
1
Are an

y of the resistances greater than 5 ohms?
Yes REPAIR the high resistance circui t. For additional information, refer to the wiring diagrams. CLEAR
the DTC. TEST the system for normal operation.
No GO to A5
.
A5: CHECK THE EGR VALVE T
O ECM CIRCUITS FOR SHORT TO HIGH VOLTAGE
R
e
connect the battery negative terminal.
1
Meas
ure t
he voltage between the following:
PI34, pin
0
4 (YU) and GROUND
PI34, pin
0
1 (YG) and GROUND
PI34, pin
0
6 (YN) and GROUND
PI34, pin
0
3 (YR) and GROUND
2
Are any of th
e volt
ages greater than 3 volts?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No

Ite
m
Part
Number
Descr
iption
1—Fu

el tank pressure sensor (if applicable)
2—Engine m

anagement ECU
3—EVAP canister purge va

lve
4—EVAP ca

nister close valve (if applicable)
5—Engine
mana
gement fusebox - IGN supply
Circuit diagram
,
evaporative emissions systems

Ite
m
Par
t
Number
De
scr
iption
1—Engine

management fuse box
2—Engine
control module (E
CM)
Circuit Diagrams (extracts only)
ECM Su
pply Voltage

It
em
De
scription
1Mechanica

l guard
position sensor (potentiometer)
2Pedal demand sensors (pot
entiometers)
3Thro

ttle position sensor
4Engine

control
module (ECM)
5Throttl
e motor power relay
6EMS fuse box
7Throttl

e motor
T
hrottle Sensors and Control