1998 JAGUAR X308 ignition switch

Engine Igni
tion -
Engine Ignition
Description an
d Operation
I

gnition coil and spark plug reference
Any positional r
eferences are base
d upon the following convention:
viewing from the driving position, the right-hand cylinder bank is designated bank 1 (A on circuit diagrams) and the left-
hand cylinder bank as bank 2 (B on circuit diagrams).
The cylinder bores of each bank are number ed 1 to 4, from the front of the vehicle.
Ig
nition System
Th
e ignition system provides timing cont
rol in accordance with the engine mana gement strategy and powertrain sensor
inputs; the system consists of:
engine
control module
igni

tion coils supply relay
ignit

ion control modules
igni

tion coils
spark plu

gs
Engine Control Module (ECM)
pr

ovides triggering for the ignition control modules
to control individual firing of the spark plugs
supplies ground for
the igni
tion coils supply relay
I
gnition Coils Supply Relay
The
ignition coils supply relay is located
in the engine and transmission control mo dule compartment; refer to Relay Details
in Electrical Wiring and Circuit Protection, Section 418-01.
The ECM switches a ground to the coil of the ignition coils supply relay; the relay energizes and switches a 12v supply to the
ignition control modules and the ignition coils.
I
gnition Control Modules

Engine Igni
tion -
Engine Ignition
D
iagnosis and Testing
I

nspection and Verification
1.
1. Veri
fy the customer concern.
2. 2. Confirm which, if any, warning li ghts and/or messages were displayed on the instrument cluster.
• NOTE: If any warning lights and/or me ssages were displayed when the fault occurred, refer to the Driver Information
table for DTCs associated with the display, then to the DTC index table for possible sources and actions. Some warnings will
appear to clear when the ignition is cycl ed. This is often because the warning has flagged as a resu lt of one of the vehicle's
on-board diagnostic routines having run to detect the fault. If the same routine is not run when the ignition is switched ON,
the warning will not reflag until the routine does run. See the DTC summaries for drive cycle routines.
3. 3. Visually inspect for obvious signs of mechanical or electrical damage.
V
isual Inspection Chart
4.
4. Veri
fy the following syst
ems are working correctly:
Air in
take system
Coo

ling system
Charging system


F

uel charging system
5. 5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding
to the next step.
6. 6. Where the Jaguar approved diagnostic sy stem is available, complete the S93 report before clearing any or all fault
codes from the vehicle.
• NOTE: If a DTC cannot be cleared, then there is a permanent fault present that flag s again as soon as it is cleared (the
exception to this is P1260, which will only clear following an ignition OFF/ON cycle after rectification).
7. 7. If the cause is not visually evident and the Jaguar approv ed diagnostic system is not available, use a fault code
reader to retrieve the fault codes be fore proceeding to the Diagnostic Trou ble Code (DTC) Index Chart, or the
Symptom Chart if no DTCs are set.
• NOTE: If the DTC flagged was not present for two or more co nsecutive cycles, it is classed as temporary, and will be
deleted following three cycl es during which no fault was present. This could result in a reported wa rning light/message with
no stored DTCs. If a fault is present for three consecutive cycles, the DTC becomes permanent, and will remain in the
module's memory for 40 drive cycles (a cy cle is an ignition ON/OFF, which will occur during the owner's normal use of the
vehicle. No action on the part of the technician is necessary to perform this cycle. A drive cycle is a series of conditions
needed to make the on-board diagnostic ro utine run, and may need a specific action on the part of the technician. See the
DTC summaries for driv e cycle routines).
8. 8. Using the Jaguar approved diagnostic system where available, and a scan tool where not, check the freeze frame
data for information on the conditions applicable when the fault was flagged. The format of this will vary,
depending on the tool used, but can pr ovide information useful to the technician in diagnosing the fault.
CAUTION: When probing connectors to take measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
MechanicalElectrical
Engi
ne oil level
Coo

ling system coolant
level
Fuel contamination

Throttle body Poly

-vee belt
F
uses
W

iring harness
E

lectrical connector(s)
Sens

or(s)
Engine

control module (ECM)
Relay date codes.

If the date on the relay is between R6 k1 and R6 k8, replace
the relay

P
arts List
It

em
Par
t Number
De
scription
1—PI032

VVT solenoid 2
2—PI027

KS 2
3—PI004

ECT sensor
4—PI026

KS 1
5—PI031

VVT solenoid 1
6—PI035

MAFS (on vehicle)
7—PI050

Generator
8—PI040

Oil pressure switch
9—PI018

to PI021 Bank 1 Ignition coils 1 to 4
PI022 to PI025 Bank 2 Ignition coils 1 to 4
10—PI006
Throttle valve position sensor
11—PI002 En

gine management harness (on vehicle)
12—PI001 En

gine management harness (on vehicle)
13—PI033

Throttle valve motor
14—PI034

EGR valve (where fitted)
15—PI015 CM

P sensor
16—PI042

Accelerator pedal and
mechanical guard sensors
17—PI007
to PI010 Bank 1 Injectors 1 to 4 PI011 to PI014 Bank 2 Injectors 1 to 4
18—PI037

Compressor lock
sensor (where fitted)
19—PI036
Compressor clutch
20—PI017 CK

P sensor
E
ngine Harness Connectors
Location

E
lectronic Engine Controls -
Electronic Engine Controls
D
iagnosis and Testing
I

nspection and Verification
1.
1. Veri
fy the customer concern.
2. 2. Confirm which, if any, warning li ghts and/or messages were displayed on the instrument cluster.
• NOTE: If any warning lights and/or me ssages were displayed when the fault occurred, refer to the Driver Information
table for DTCs associated with the display, then to the DTC index table for possible sources and actions. Some warnings will
appear to clear when the ignition is cycl ed. This is often because the warning has flagged as a resu lt of one of the vehicle's
on-board diagnostic routines having run to detect the fault. If the same routine is not run when the ignition is switched ON,
the warning will not reflag until the routine does run. See the DTC summaries for drive cycle routines.
3. 3. Visually inspect for obvious signs of mechanical or electrical damage.
V
isual Inspection Chart
4.
4. Veri
fy the following syst
ems are working correctly:
Air in
take system
Coo

ling system
Charging system


F

uel charging system
5. 5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding
to the next step.
6. 6. Where the Jaguar approved diagnostic sy stem is available, complete the S93 report before clearing any or all fault
codes from the vehicle.
• NOTE: If a DTC cannot be cleared, then there is a permanent fault present that flag s again as soon as it is cleared (the
exception to this is P1260, which will only clear following an ignition OFF/ON cycle after rectification).
7. 7. If the cause is not visually evident and the Jaguar approv ed diagnostic system is not available, use a fault code
reader to retrieve the fault codes be fore proceeding to the Diagnostic Trou ble Code (DTC) Index Chart, or the
Symptom Chart if no DTCs are set.
• NOTE: If the DTC flagged was not present for two or more co nsecutive cycles, it is classed as temporary, and will be
deleted following three cycl es during which no fault was present. This could result in a reported wa rning light/message with
no stored DTCs. If a fault is present for three consecutive cycles, the DTC becomes permanent, and will remain in the
module's memory for 40 drive cycles (a cy cle is an ignition ON/OFF, which will occur during the owner's normal use of the
vehicle. No action on the part of the technician is necessary to perform this cycle. A drive cycle is a series of conditions
needed to make the on-board diagnostic ro utine run, and may need a specific action on the part of the technician. See the
DTC summaries for driv e cycle routines).
8. 8. Using the Jaguar approved diagnostic system where available, and a scan tool where not, check the freeze frame
data for information on the conditions applicable when the fault was flagged. The format of this will vary,
dependin
g o
n the tool used, but can provide information useful to the technician in dia
gnos
in
g th
e fault.

MechanicalElectrical
Engi
ne oil level
Coo

ling system coolant
level
Fuel contamination

Throttle body Poly

-vee belt
F
uses
W

iring harness
E

lectrical connector(s)
Sens

or(s)
Engine

control module (ECM)
Tran

smission control module
Check spark plu

g type. Only re
sisted plugs should be fitted. Refer to specifications
section for gap
Relay date codes.
If the date on the rela
y is between R6 k1 and R6 k8, replace the
relay

CAUTIO
N: When probing connectors to take
measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
• 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
Sym

ptom
(general)
S y
mptom (specific)
Possib
l
e source
Acti
o
n
No
n
-Start
Engine
does not cran
k
Starter relay ECM relay Batt
ery Park
/Neutral
switch
Starting system

Harness damage
Engine s
iezed
Check r
e
lay dates. Check
for DTCS. For starting
system,
REFER to Section 303
-06 Sta r
ting System
.
F or ECM
relay tests, GO to Pinpoint Test
AD.
.
F o
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Fo r

Park/Neutral tests, GO to Pinpoint Test AC.
. Fo
r engine information,
REFER to Section 303
-01 En
gine
.
Engine cranks, but does
not fireSecurity
syst
em /Immobiliser
engaged
Thr o
ttle contaminated
Harness damage
Fu
el pump relay
Fue
l
system
R
e
fer to service action
S491
Contact dealer techni
cal
support for information
on security system. For fuel system,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
Check bull etins for throttl
e cleaning procedure.
Check service actions.
Engine cranks an d
fires,
but will not start
F u
el pump relay
Thr
o
ttle contaminated
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Spark plugs
fouled
Ignition coil
fail
ure(s)
Check f
o
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
Cyli
nder compression loss
(short-term. Refer to bulletin; 303-52)
Re
fer to service action
S491
Fo
r fuel pump relay tests,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
. Check bulletins for throttl
e cleaning procedure.

Check fuel pressure. Refe r to Technical service
bulletins. For ECT sensor tests, GO to Pinpoint Test C.
. Fo
r ignition system,
REFER to Section 303
-07 En
gine Ignition
.
Check bulletins an d service a
ctions.
Di
f
ficult to
start
D iff
icult to start cold
Roc
h
ester valve
Batt
ery Thro
ttle contaminated
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Purge val
ve
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Blocked part-load breather (s
ervice action S474)
R
e
fer to service action
S491
For R
ochester valv
e test, GO to Pinpoint Test AE.
. Fo
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Check bull etins for throttl
e cleaning procedure.
Check fuel pressure. For ECT sensor circuit tests,
GO to Pinpoint Test C.
. F
or evaporative
emissions tests,
REFER to Section 303
-1 3
Evaporative
Emiss
i
ons
.
R e
fer to bulletins for co
mpression information,
and service actions for part-load breather procedure and compressions.
Diff
icult to start hot
Roc
h
ester valve
Purge
val
ve
Thr
o
ttle contaminated
F
or R
ochester valv
e test, GO to Pinpoint Test AE.
. F
or evaporative emissions tests,
REFER to Section 303
-1 3
Evaporative

Driver Information
Chart
•

NOTE: Use this table to identify DTCs associated with the me
ssage center display, then refer to the DTC index for possible
sources and actions.
• NOTE: For definitions of Default Modes, see the foot of this table.
Poor
dr iveabilityEngine h e
sitates/poor
acceleration
Fue l
pump
Exhaus
t gas
recirculation
(EGR)
Air leakage Stop lamp swi t
ch
Throttl
e
sensors
Throttl
e
motor
Spark
plugs
fouled
Check f
o
r water ingress
into spark plug wells
Ignition coil fail
ure(s)
HT sh
o
rt to ground
(tracking) check rubber
boots for cracks/damage
ECM failu r
e
Check f
u
el pressure. For EGR information,
REFER to Section 303
-08 En gin
e Emission
Control.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution

and F
ilt
ering
.
F or stop l
amp switch in
formation, refer to the
wiring diagrams. For throttle position sensor
tests,GO to Pinpoint Test D.
. Fo
r throttle motor
control circuit tests,GO to Pinpoint Test T.
. For
igni t
ion system,
REFER to Section 303
-07 En
gine Ignition
.
F or ECM
circuit tests,GO to Pinpoint Test
AD.
.
Engine backfiresFuel
pump
Air leakage MAF se

nsor
HO2 sensors
Spark plugs Check fo
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
Ignition coil fail
ure(s)
Chec
k fu
el pressure. For intake system
information,
REFER to Section 303
-12
Intake Air Distribution

and Filt
ering
.
F or MAF sensor ci
rcuit test
s,GO to Pinpoint Test
A.
. F or HO2 sensor
circui
t tests, check for DTC
indicating which sensor and follow indicated pinpoint test. For ignition system,
REFER to Section 303
-07 En
gine Ignition
.
Engine
s
urges
Air leakage
Fuel
pump
Stop lamp swit

ch
MAF s
e
nsor
Harness Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
ECM failu r
e
Fo
r
intake system,
REFER to Section 303
-1 2
Intake Air Distribution

and Filt
ering
.
Check fu
el pressure. For
stop lamp information,
refer to the wiring diagrams. For MAF sensor tests,GO to Pinpoint Test A.
. Fo
r throttle
position sensor tests,GO to Pinpoint Test D.
,
a n
dGO to Pinpoint Test
K.
. Fo
r throttle motor
circuit tests,GO to Pinpoint Test T.
. For ig
nition
system,
REFER to Section 303
-07 En
gine Ignition
.
F or ECM
circuit tests,GO to Pinpoint Test
AD.
.
Engine detonates/k
nocks
Fue
l
pump
HO2 sensors
Air leakage Blocked part-load breather
(s
ervice action S474)
Mass ai
r fl
ow (MAF) sensor
Chec
k fu
el pressure. Fo
r HO2 sensor circuit
tests, check for DTC indicating which sensor and
follow indicated pinpoint test. For intake system
information,
REFER to Section 303
-1 2
Intake Air Distribution

and Filt
ering
.
Check service action S474
. For MAF sensor
tests,GO to Pinpoint Test A.
.
No t
hrottle response
Traction contr
o
l invoked
Throttl
e
sensors
Throttl
e
motor
Fo
r th
rottle position sensor tests,GO to Pinpoint
Test D.
, andG O to Pinpoint
Test
K.
. Fo
r throttle

motor circuit tests,GO to Pinpoint Test T.
.
Cru i
se control inhibited or

disabled
Cru i
se control switch
Throttle

sensors
Stop lamp swit

ch
For cru
i
se control switches,
REFER to Section 310
-03
Speed Control
.
For th
rottle position sensor tests,GO to Pinpoint
Test D.
, andG O to Pinpoint
Test
K.
. For s t
op
light switch information, refer to the wiring diagrams.

or sho
rt circuit to B+ voltage
Ignition modul
e
2 ground circuit
fault
Ignition coil relay fai
lure
Ignition coil
open/short
circuit
Ignition modul
e
2 failure
P1474Int
e
rcooler coolant pump relay
malfunction
Intercooler pump relay failure

Intercooler pump relay
to ECM

drive circuit fault
Intercooler pump relay coi
l ground
circuit fault
ECM power supply f
ault
F
or i
ntercooler pump relay circuit
tests,GO to Pinpoint Test Z.
.
P1475Ra
diator fans slow
(series) circuit
malfunction
R a
diator fan control relay module
to ECM 'series' drive circuit (relay
pin 9) fault
Relay coil ignition power supply
o p
en circuit
ECM ground circuit fault (relay coil


drive)
ECT se ns
or circuit malfunction
(refer to P0116)
F o
r radiator fan seri
es circuit tests,GO
to Pinpoint Test AA.
P1476Ra
diator fans fast (parallel) circuit
malfunction
R a
diator fan control relay module
to ECM 'parallel' drive circuit (relay
pin 7) fault
Relay coil ignition power supply
o p
en circuit
ECM ground circuit faul
t (relay coil

drive)
ECT sens
or circuit malfunction
(refer to P0116)
F or radi
ator fan parallel circuit
tests,GO to Pinpoint Test AB.
.
P1516Gear change PARK
/NEUTRAL

driving malfunction
Transmission range (T
R) sensor to
ECM circuit open circuit or high
resistance
TR sensor f
ailure
D-
4
switch to TCM circuit open
circuit or high resistance
D-4 swi
tch fault
For

PARK/NEUTRAL tests,GO to
Pinpoint Test AC.
.
P1517Engine PA
RK/NEUTRAL
cranking
malfunction
Transmissi on range (T
R) sensor to
ECM circuit open circuit or high
resistance
TR sensor f
ailure
Fo
r

PARK/NEUTRAL tests,GO to
Pinpoint Test AC.
.
P1571Brake swit
ch malfunction
Brake sw
it
ch to ECM circuit open
circuit, short circ uit to ground, high
resistance
Brake sw it
ch ignition switched
ground circuit open circuit
Brake sw it
ch failure
Brake ca
ncel
switch to ECM circuit
open circuit, short circuit to
ground, high resistance
Brake ca nce
l switch to cruise
(speed) control switch circuit open
circuit, short circ uit to ground, high
resistance
Brake cance
l switch ignition
switched power supply open circuit
Brake ca nce
l switch failure
Cru
i
se (speed) control switch
failure
For cru i
se (speed) control circuit tests,
REF
E
R to Section 310
-03
Sp
eed
Control.
P1606Engine
m
anagement system
(EMS) control relay malfunction
ECM co ntrol rel
ay failure
ECM c
o
ntrol relay to ECM circuit
fault
ECM co ntrol rel
ay coil power supply

open circuit
ECM ground circuit faul t (relay coil

drive)
F or ECM
relay circuit tests,GO to
Pinpoint Test AD.
.
P1609EC
M microprocessor-to-
microprocessor communication
ECM failu r
e
Contact deal
er techni
cal support for
advice on possible ECM failure.

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.