1998 JAGUAR X308 fuel diagram

Pinpoint Tests
f
ailure
P1611Thr

ottle angle malfunction
TP sensor
circuit fault (refer to
P0121)
APP sensor circuit faul
t (refer to
P0121)
Throttl
e assembly failure
ECM failu

re
Se
e pinpoint tests for components
listed. For throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
Contact deal
er technical support for
advice on possible ECM failure.
P1612Throttl
e offset malfunction
TP sensor
circuit fault (refer to
P0121)
APP sensor circuit faul
t (refer to
P0121)
Throttl
e assembly failure
ECM failu

re
Se
e pinpoint tests for components
listed. For throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
Contact deal
er technical support for
advice on possible ECM failure.
P1637CAN AB
S/TCCM token missing
CAN
open circuit fault - ABS/TCCM
to ECM
CAN s
hort circuit fault
ABS/TCCM failu

re
ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1638CAN INST token missingCAN

open circuit fault - INST to
ECM
CAN s
hort circuit fault
INST

failure
ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1642CAN c

ircuit malfunction
CAN s
hort circuit fault
Control modul

e failure - check for
additional logged DTCs to locate
control module source
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1643CAN TC

M token missing
CAN
open circuit fault - TCM to
ECM
CAN s
hort circuit fault
TCM failure


ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1646F

uel pump 2 relay malfunction.
NOTE: This DTC applies only to
the S/C fuel pump 2
F
uel pump 2 relay failure
F

uel pump 2 relay to ECM circuit
fault
F
uel pump 2 relay coil power
supply open circuit
ECM ground circuit faul
t (relay coil
drive)
F
or fuel pump 2 relay circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P

INPOINT TEST A : DTC P0101, P0102, P0103; MASS AIR FLOW (MAF) SENSOR
RANGE/PERFORMANCE, HIGH/LOW VOLTAGE
•
NOTE: Before commencing this
test, check the air filter for blockage, the engine air inta ke and breather systems for
leaks, and the TPS for additional DTCs.
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1: CHECK

THE MAF SENSOR SENS
E CIRCUIT FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM12.
2
Di

sconnect the MAF sensor electrical connector, PI35.
3
Meas

ure the resistance between EM12, pin 13 (GY) and PI35, pin 02 (GY).
4
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 A2
.
A2: CHECK
THE MAF SENSOR SENSE CI
RCUIT 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 the MAF sensor electrical connector, PI35, pin 02 (GY) and GROUND.
3
Is th

e voltage greater than 3 volts?

D
isconnect the ECM electrical connector, EM14.
2
IN

STALL the throttle motor relay.
3
R

econnect the battery negative terminal.
4
Turn the ignition swi

tch to the
ON position.
5
Measure the
voltage between EM14, pi
ns 01 and 02, (GY) and GROUND.
6
Is the vol
tage greater than 10 volts?
Yes GO to T6
.
No

INSTALL a new throttle motor relay. For additional information, refer to the electrical guide. CLEAR
the DTC. TEST the system for normal operation.
T
6: CHECK THE THROTTLE MOTOR TO ECM DRIVE SUPPLY CIRCUIT FOR HIGH RESISTANCE
Di

sconnect the throttle motor electrical connector, PI33.
1
Meas

ure the resistance between PI33, pi
n 01 (R) and EM14, pins 05 and 06 (R).
2
Is either resi
stance
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 T7
.
T
7: CHECK THE THROTTLE MOTOR TO ECM DRIVE GROUND CIRCUIT FOR HIGH RESISTANCE
Meas

ure the resistance between PI33, pin
02 (G) and EM14, pins 11 and 12 (G).
1
Is either resi
stance
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 T8
.
T
8: CHECK THE THROTTLE MOTOR TO ECM DRIVE SU
PPLY CIRCUIT FOR SHORT TO HIGH VOLTAGE
Re
connect the ECM electrical connector, EM14.
1
Turn the ignition swi

tch to the
ON position.
2
M
easure the voltage between PI33, pin 01 (R) and GROUND.
3
Is the vol

tage greater than 10 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 T9
.
T
9: CHECK THE THROTTLE MOTOR TO ECM DRIVE SUPPLY CIRCUIT FOR SHORT TO GROUND
D

isconnect the ECM electrical connector, EM14.
1
Turn the ignition swi

tch to the
OFF position.
2
Meas
ure the resistance between PI33, pin 01 (R) 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 INSTALL a new throttle motor.
REFER to Section 303
-0
4 Fuel Charging and Controls
.
CLEAR t
he DTC. TEST the system for normal operation.
P

INPOINT TEST U : DTC P1226; MECHANICAL
GUARD SENSOR RANGE/PERFORMANCE, HIGH /LOW
VOLTAGE
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
U1: CHECK T

HE MECHANICAL GUARD SENSE CIRCUIT FOR HIGH RESISTANCE
Di

sconnect the battery negative terminal.
1
Di

sconnect the mechanical guard sensor electrical connector, PI42.
2
D

isconnect the ECM electrical connector, EM11.
3
Me

asure the resistance between PI42, pin 01 (BY) and EM11, pin 13 (BY).
4
Is th

e resistance greater than 5 ohms?

Yes
R
EPAIR 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 U2
.
U2: CHECK T H
E MECHANICAL GUARD SENSE
CIRCUIT FOR SHORT TO HIGH VOLTAGE
Re
connect the battery negative terminal.
1
Turn the ignition swi
t
ch to the ON
position.
2
Measure t
he voltage between PI42, pin 01 (BY) and GROUND.
3
Is the volt

age greater than 10 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 U3
.
U3: CHECK T H
E MECHANICAL GUARD SE
NSE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swit
ch to the OFF
position.
1
Measure t
he resistance between PI42, pin 01 (BY) 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 U4
.
U4: CHECK THE MEC H
ANICAL GUARD SENSOR POWER SUPPLY CIRCUIT
Re
conn
ect the ECM electrical connector, EM11.
1
Turn the ignition swi
t
ch to the ON
position.
2
Measure t
he voltage between PI42, pin 04 (UW) and GROUND.
3
Is th
e volt
age less than 5 volts?
Yes
REPAIR the power supply circuit. This circuit includ es the ECM. For additional information, refer to
the wiring diagrams. CLEAR the DTC. TE ST the system for normal operation.
No INSTALL a new mechanical guard sensor. CLEAR the DTC. TEST the system for normal operation.
PINPO
INT TEST V : DTC P1240, P1241, P1242
; SENSOR REFERENCE VOLTAGE MALFUNCTION,
HIGH/LOW VOLTAGE (THROTTLE SENSORS, FUEL TANK PRESSURE SENSOR)
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
V
1
: CHECK THE REFERENCE VOLTAGE AT TH
E APP SENSOR/MECHANICAL GUARD SENSOR
Disc
onnect the APP sensor electrical connector, PI42.
1
Turn the ignition swi
t
ch to the ON
position.
2
Measure the voltage between PI
42,
pin 04 (UW) and GROUND.
3
Is th
e volt
age less than 5 volts?
Yes GO to V2
.
No
GO to V3
.
V2
: CHECK THE APP SENSOR/MECHA
NICAL GUARD SENSOR REFERENCE VOLTAGE CIRCUIT FOR HIGH
RESISTANCE
Di sc
onnect the battery negative terminal.
1
D
i
sconnect the ECM electrical connectors, EM10 and EM11.
2
Me
asure
the resistance between PI42, pin 04 (UW) and EM10, pin 21 (UW).
3
Me
asure
the resistance between PI42, pin 04 (UW) and EM11, pin 08 (UW).
4
Is either resi
stance 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 V3
.
V3
: CHECK THE APP SENSOR/MECHA
NICAL GUARD SENSOR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO
HIGH VOLTAGE

R
econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
Measure the
voltage between PI
42, pin 04 (UW) and GROUND.
3
Is th
e voltage greater than 6 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 V4
.
V
4: CHECK THE APP SENSOR/MECHA
NICAL GUARD SENSOR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO
GROUND
Turn the ignition swi
tch to the
OFF position.
1
Meas
ure the resistance between PI42, pin 04 (UW) 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 V5
.
V
5: CHECK THE REFERENCE VOLTAGE AT THE THROTTLE POSITION SENSOR
Re

connect the ECM electrical connectors, EM10 and EM11.
1
Disc

onnect the TP sensor electrical connector, PI06.
2
Turn the ignition swi

tch to the ON
position.
3
Measure the
voltage between PI
06, pin 04 (UW) and GROUND.
4
Is th
e voltage less than 5 volts?
Yes GO to V6
.
No

GO to V7
.
V
6: CHECK THE THROTTLE POSITION SENSOR REFE
RENCE VOLTAGE CIRCUIT FOR HIGH RESISTANCE
Turn the ignition swi
tch to the OFF
position.
1
D
isconnect the ECM electrical connectors, EM10 and EM11.
2
Me

asure the resistance between PI06, pin 04 (UW) and EM10, pin 21 (UW).
3
Me

asure the resistance between PI06, pin 04 (UW) and EM11, pin 08 (UW).
4
Is either resi

stance
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 V7
.
V
7: CHECK THE THROTTLE POSITION SENSOR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO HIGH VOLTAGE
Turn the ignition swi

tch to the ON
position.
1
Measure the
voltage between PI
06, pin 04 (UW) and GROUND.
2
Is th
e voltage greater than 6 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 V8
.
V
8: CHECK THE THROTTLE POSITION SENSOR REFE
RENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swi
tch to the OFF
position.
1
Meas
ure the resistance between PI06, pin 04 (UW) 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 V9
.
V
9: CHECK THE REFERENCE VOLTAGE AT THE FUEL TANK PRESSURE SENSOR
Di

sconnect the FTP sensor electrical connector, FP01.
1
Re

connect the ECM electrical connectors, EM10 and EM11.
2
Turn the ignition swi

tch to the ON
position.
3

Measure the voltage between FP 01
, pin 03 (UW) and GROUND.
4
Is th
e volt
age less than 5 volts?
Yes GO to V10
.
No
CHECK
for DTCs associated with
TP sensor, APP/mechanical guard sensor, or FTP sensor. INSTALL a
new sensor as indicated by the DTC. CLEAR the DTC. TEST the system for normal operation.
V
10: CHECK
THE FUEL TANK PRESSURE SENSOR
REFERENCE VOLTAGE CIRCUIT FOR HIGH RESISTANCE
Disc
onnect the battery negative terminal.
1
D
i
sconnect the ECM electrical connectors, EM10 and EM11.
2
Measure t

he resistance between FP01,
pin 03 (UW) and EM10, pin 21 (UW).
3
Measure t
he resistance between FP01,
pin 03 (UW) and EM11, pin 08 (UW).
4
Is either 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 V11
.
V11: CHECK
THE FUEL TANK PRESSURE SENSOR REFE
RENCE VOLTAGE CIRCUIT FOR SHORT TO HIGH VOLTAGE
Re
connect the battery negative terminal.
1
Turn the ignition swi
t
ch to the ON
position.
2
Measure the voltage between FP 01
, pin 03 (UW) and GROUND.
3
Is th
e volt
age greater than 6 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 V12
.
V12: CHECK
THE FUEL TANK PRESSURE SENSOR
REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
Turn the ignition swit
ch to the OFF
position.
1
Measure t
he resistance between
FP01, pin 03 (UW) 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 CHECK for DTCs associated with TP sensor, APP/mechanical guard sensor, or FTP sensor. INSTALL a
new sensor as indicated by the DTC. CLEAR the DTC. TEST the system for normal operation.
PI
NPOINT TEST W : DTC P1243; SENSOR RE
FERENCE GROUND MALFUNCTION (THROTTLE
SENSORS, FUEL TANK PRESSURE SENSOR, ECT, IAT, IAT 2 SENSORS)
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
W1: CHECK THE SENSO
R
REFERENCE
GROUND AT THE THROTTLE SENSORS
Disc
onne
ct the TP sensor electrical connector, PI06.
1
Meas
ure t
he resistance between PI06, pin 01 (BG) and GROUND.
2
Is th
e res
istance greater than 5 ohms?
Yes GO to W2
.
No
GO to W3
.
W2: CHECK TH
E THROTTLE SENSOR REFERENCE GROUND CIRCUIT FOR HIGH RESISTANCE
D
i
sconnect the ECM electrical connectors, EM10 and EM11.
1
Meas
ure t
he resistance between PI06,
pin 01 (BG) and EM10, pin 20 (BG).
2
Measure t
he resistance between PI06,
pin 01 (BG) and EM11, pin 12 (BG).
3
Is either 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 W3
.
W3: CHECK THE SENSO R
REFERENCE GROUND AT
THE APP SENSOR/MECHANICAL GUARD SENSOR

Di
sconnect the APP sensor/mechanical guard sensor electrical connector, PI42.
1
Re

connect the ECM electrical connectors, EM10 and EM11.
2
Meas

ure the resistance between PI42, pin 02 (BG) and GROUND.
3
Is th

e resistance greater than 5 ohms?
Yes GO to W4
.
No

GO to W5
.
W4: CHECK THE APP
SENSOR/MECHANICAL GUARD SE
NSOR REFERENCE GROUND CIRCUIT FOR HIGH
RESISTANCE
D
isconnect the ECM electrical connectors, EM10 and EM11.
1
Meas

ure the resistance between PI42,
pin 02 (BG) and EM10, pin 20 (BG).
2
Meas
ure the resistance between PI42,
pin 02 (BG) and EM11, pin 12 (BG).
3
Is either resi
stance
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 W5
.
W5: CHECK THE SENSO
R REFERENCE GROUND AT THE FUEL TANK PRESSURE SENSOR
Di

sconnect the FTP sensor electrical connector, FP01.
1
Re

connect the ECM electrical connectors, EM10 and EM11.
2
Meas

ure the resistance between
FP01, pin 01 (BG) and GROUND.
3
Is th
e resistance greater than 5 ohms?
Yes GO to W6
.
No

GO to W7
.
W6: CHECK THE FUEL
TANK PRESSURE SENSOR RE
FERENCE GROUND CIRCUIT FOR HIGH RESISTANCE
D
isconnect the ECM electrical connectors, EM10 and EM11.
1
Meas

ure the resistance between FP01,
pin 01 (BG) and EM10, pin 20 (BG).
2
Meas
ure the resistance between FP01,
pin 01 (BG) and EM11, pin 12 (BG).
3
Is either resi
stance
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 W7
.
W7: CHECK THE SENSO
R REFERENCE GROUND AT THE ECT SENSOR
Re

connect the ECM electrical connectors, EM10 and EM11.
1
D

isconnect the ECT sensor electrical connector, PI04.
2
Meas

ure the resistance between PI04, pin 01 (BG) and GROUND.
3
Is th

e resistance greater than 5 ohms?
Yes GO to W8
.
No

GO to W9
.
W8: CHECK THE ECT SEN
SOR REFERENCE
GROUND CIRCUIT FOR HIGH RESISTANCE
D
isconnect the ECM electrical connectors, EM10 and EM11.
1
Meas

ure the resistance between PI04,
pin 01 (BG) and EM10, pin 20 (BG).
2
Meas
ure the resistance between PI04,
pin 01 (BG) and EM11, pin 12 (BG).
3
Is either resi
stance
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 W9
.
W9: CHECK THE SENSO
R REFERENCE GR
OUND AT THE IAT SENSOR (MAF)
Re
connect the ECM electrical connectors, EM10 and EM11.
1
Di

sconnect the IAT sensor (MAF) electrical connector, PI35.
2
Meas

ure the resistance between PI35, pin 04 (BG) and GROUND.
3

The upstream heated oxygen sensor is located at the catalytic converter inlet and detects the concentration of oxygen in the
raw exhaust gases; an internal heater reduces the warm up time of the sensor output.
An oxygen sensor (without heater) is located at the converter outlet.
The ECM receives input signals from the se nsors and varies the fuel injector duration (mixture) to provide optimum gas
emissions.
Circuit Diagram, O2 Sensors / ECM

Ite
m
Par
t
Number
De
scr
iption
1—Engine
m
anagement ECM
2—Boot fuse box

3—Fue
l
pump

Ci
rcui
t Diagram, Fuel Pump -
Normally Aspirated Vehicles