1998 JAGUAR X308 fuse diagram

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

Yes
R
EPAIR the short circuit. For addi
tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to A3
.
A3: CHECK THE MAF SENSO
R SENS
E CIRCUIT FOR SHORT TO GROUND
• NO
TE: The short to GROUND may be intermittent. Move the
wiring to attempt to reproduce the conditions under which
the DTC was logged, and visually inspect the harness for any signs of chafing, see "visual inspection chart".
Turn the ignition swit
ch to the OFF
position.
1
Measure t
he resistance between PI35, pin 02 (GY) and GROUND.
2
Is t

he resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to A4
.
A4: CHEC K THE MA
F SENSOR SUPPLY CIRCUIT VOLTAGE
Re
conn
ect the ECM electrical connector, EM12.
1
Turn the ignition swi
t
ch to the ON
position.
2
Me
asure the voltage between the MAF sensor electrical connector, PI35, pin 01 (WU) and GROUND.
3
Is the vol
t
age greater than 10 volts?
Yes GO to A5
.
No
REP
AIR the circuit between the MAF sensor electric
al connector, PI35, pin 01 (WU) and BATTERY. This
circuit includes the EMS control rela y, fuse 12 of the EMS fuse board, and splices in the harness. For
additional information, refer to the wiring diagrams. CLEAR the DT C. TEST the system for normal
operation.
A5: CHECK THE MAF SENSO
R SUPPLY CIRCUIT FOR HIGH RESISTANCE
Di
sc
onnect the battery negative terminal.
1
Di
sc
onnect the EMS fuse board electrical connector, EM20.
2
Meas
ure t
he resistance between EM20,
pin 10 (WU) and PI35, pin 01 (WU).
3
Is the res
istance 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 MAF sensor.
REFER to Mass Air Flow (MAF) Sensor
in this
section.
CLEAR the DTC. TEST the system for normal operation.
P INPOINT TES
T B : DTC P0111, P0112, P0113;
INTAKE AIR TEMPERATURE (IAT) SENSOR
RANGE/PERFORMANCE, HIGH/LOW VOLTAGE
•
NOTE: Before commencing this
test, check the air filter for blockage and the engine air intake and breather systems for
leaks.
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
B1: CHECK
THE IAT SENSOR
SENS
E CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the battery negative terminal.
1
D
i
sconnect the ECM electrical connector, EM12.
2
Di
sc
onnect the MAF sensor electrical connector, PI35.
3
Me
asure
the resistance between EM12, pin 12 (UP) and PI35, pin 03 (UP).
4
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 GO to B2
.
B2: CHECK
THE IAT SENSOR SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE
R
e
connect the battery negative terminal.
1
Turn the ignition swi
t
ch to the ON
position.
2
Measure the voltage between PI 35,
pin 03 (UP) and GROUND.
3

Is
the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to E4
.
E4
: CHECK THE H02S GROUND
CIRCUIT FOR OPEN CIRCUIT
Re
connect the ECM electrical connector, EM12.
1
Meas

ure the resistance between EM21, pin 04 (BRD) and GROUND.
2
Is th

e resistance greater than 5 ohms?
Yes
REPAIR the circuit (this is a braide d lead which would require different repair techniques to standard
wiring). For additional information, refer to the wiring diagrams. CL EAR the DTC. TEST the system for
normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.
CLEAR the DTC. TEST the syst em for normal operation.
PI
NPOINT TEST F : DTC P0133, P0135; RIGHT-HAND H02S HEATER CIRCUIT MALFUNCTION
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
F1:

CHECK THE H02S HEATER POWER SUPPLY CIRCUIT
D

isconnect the H02S electrical connector, EM21.
1
Turn the ignition swi

tch to the ON
position.
2
Meas
ure the voltage between EM21, pin 02 (WP) and GROUND.
3
Is the vol

tage greater than 10 volts?
Yes GO to F2
.
No

REPAIR the circuit. This circuit in cludes the EMS control relay and fu se 14 of the EMS fuse board. For
additional information, refer to the wiring diagrams. CLEAR the DT C. TEST the system for normal
operation.
F2: CHECK THE H02
S HEATER CONTROL CI
RCUIT FROM ECM FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM15.
2
Me

asure the resistance between EM15, pin 02 (PU) and EM21, pin 01 (PU).
3
Is th

e resistance 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 F3
.
F3: CHECK THE H02
S HEATER CONTROL CIRCUI
T FROM ECM FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
Meas
ure the voltage between EM21, pin 01 (PU) and GROUND.
3
Is th

e voltage 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 GO to F4
.
F4: CHECK THE H02
S HEATER CONTROL CI
RCUIT FROM ECM FOR SHORT TO GROUND
Turn the ignition swi
tch to the OFF
position.
1
Meas
ure the resistance between EM21, pin 01 (PU) and GROUND.
2
Is

the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.

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 H2
.
H
2: CHECK THE H02S SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE
R

econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
M
easure the voltage between EM12, pin 14 (G) and GROUND.
3
Is th

e voltage 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 GO to H3
.
H
3: CHECK THE H02S SENSE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swi

tch to the OFF
position.
1
Meas
ure the resistance between EM12, pin 14 (G) and GROUND.
2
Is

the resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to H4
.
H4:
CHECK THE H02S GROUND CIRCUIT FOR OPEN CIRCUIT
Re

connect the ECM electrical connector, EM12.
1
Meas

ure the resistance between EM23, pin 04 (BRD) and GROUND.
2
Is th

e resistance greater than 5 ohms?
Yes REPAIR the circuit (this is a braide d lead which would require different repair techniques to standard
wiring). For additional information, refer to the wiring diagrams. CL EAR the DTC. TEST the system for
normal operation.
No INSTALL a new H02S.
REFER to Heated Oxygen Sensor (HO2S) RH

in this section.
CLEAR the DTC. TEST the syst em for normal operation.
P
INPOINT TEST I : DTC P0153, P0155; LEFT-HAND H02S HEATER CIRCUIT MALFUNCTION
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
I

1: CHECK H02S HEATER POWER SUPPLY CIRCUIT
D

isconnect the H02S electrical connector, EM23.
1
Turn the ignition swi

tch to the
ON position.
2
Meas
ure the voltage between EM23, pin 02 (WP) and GROUND.
3
Is the vol

tage greater than 10 volts?
Yes GO to I2
.
No

REPAIR the power supply circuit to the H02S heater. This circuit includes the EMS control relay and
fuse 14 of the EMS fuse board. For additional info rmation, refer to the wiring diagrams. CLEAR the
DTC. TEST the system for normal operation.
I
2: CHECK H02S HEATER CONTROL CIRC
UIT FROM ECM FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM15.
2
Meas

ure the resistance between EM15,
pin 01 (PS) and EM23, pin 01 (PS).
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 GO to I3
.
I
3: CHECK H02S HEATER CONTROL CIRCUIT
FROM ECM FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.

Yes
GO to N3.
No
CLEAN th
e sensor and whee
l. INSTALL the sensor.
REFER to Camshaft Position (CMP) Sensor
in this
section.
CLEAR the DTCs. TEST the system for normal operation.
O3: CHECK THE CM P SEN
SOR SENS
E CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the battery negative terminal.
1
D
i
sconnect the ECM electrical connector, EM13.
2
Meas
ure t
he resistance between EM13, pin 20 (B) and PI15, pin 01 (B).
3
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 O3
.
O4: CHECK THE CM P SEN
SOR SENSE CI
RCUIT FOR SHORT TO HIGH VOLTAGE
Re
connect the battery negative terminal.
1
Turn the ignition swi
t
ch to the ON
position.
2
Me
asure the voltage between EM13, pin 20 (B) and GROUND.
3
Is th
e volt
age 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 GO to O5
.
O5: CH ECK THE CM
P SENSOR SENSE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swi
t
ch to the OFF
position.
1
Me
asure the resistance between PI15, pin 01 (B) and GROUND.
2
Is
t
he resistance less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No INSTALL a new CMP sensor.
REFER to Camshaft Position (CMP) Sensor
in this
section.
CLEAR the DTC. TEST the system for normal operation.
P I
NPOINT TEST P : DTC P0560; VEHICLE VOLTAGE MALFUNCTION
•
NOTE
: When checking the EMS switched supplies to the ECM
in test P3, the EMS relay must be energized when testing
EM10, pin 01 and EM14, pin 03.
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
P1: CHECK

THE BATTERY POWER SUPPLY TO THE ECM
D
i
sconnect the ECM electrical connector, EM10.
1
Measure the
voltage between EM 10,
pin 09 (NO) and GROUND.
2
Is the vol
t
age greater than 10 volts?
Yes GO to P2
.
No
REPAIR th
e battery power supply circ
uit. This circuit includes fuse 4 of the EMS fuse board. For
additional information, refer to the wiring diagrams. CLEAR the DT C. TEST the system for normal
operation.
P2: CHECK
THE IGNITION SWITCH
ED POWER SUPPLY TO THE ECM
Turn the ignition swit
ch to the
ON position.
1
Meas
ure t
he voltage between EM10, pin 05 (WK) and GROUND.
2
Is the vol
t
age greater than 10 volts?
Yes GO to P3
.
No
REP
AIR the ignition switched power supply circuit. This circuit includes fuse 9 of the right-hand
heelboard fuse box. For a dditional information, refer to the wiri ng diagrams. CLEAR the DTC. TEST the
system for normal operation.