engine ignition JAGUAR X308 1998 2.G Repair Manual

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

T w
o ignition control modules control firing of the spark plug
s when triggered by the engine control module (ECM); the
modules provide an interface between the ECM and the coil on plugs such that:
Ignition cont
rol module 1 drives bank 1 -
coils 1 and 4, bank 2 - coils 2 and 3.
Ignition cont
rol module 2 drives bank 1 -
coils 2 and 3, bank 2 - coils 1 and 4.
Ite
m
Par
t
Number
De
scr
iption
1—Ignition control
module 1
2—Ignition control module 2

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

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

• NO
TE: 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
Sy
m
ptom
Possib
l
e source
Acti
o
n
Engine
cranks, but does
not fire
Secu
rit
y system /Immobiliser
engaged
Harness Fue l
system
ECM fault

Contact deal er techni
cal support for
information on security system. Check fuel
system pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For ECM tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Engine cranks and
fi
res, but will not
start
Fu
el pump relay
Fuel

pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Engine coolan t
temperature
(ECT) sensor
Spark plugs fouled, gapp
ed
incorrectly
Ignition coil fail
ure(s)
Check f
o
r water ingress into
spark plug wells
HT sho rt to ground (tracking)
check rubber
boots for
cracks/damage
Fo
r fuel pump relay tests,
REFER to: Fuel Charging and Controls
(303
-04

Fuel Charging and Controls, Diagnosis and Testing).
Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For spark plug tests, GO to Pinpoint Test B.
.
For ign i
tion system tests, GO to Pinpoint Test
A.
.
Diff
icult to start cold
Batt
ery Fuel
pump
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Spark plugs fouled, gapp
ed
incorrectly
F o
r battery information,
REFER to: Battery and Cables
(414
-01 Battery,

Mounting and Cables, Description and Operation).
Check fuel pressure.
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For compression loss, REFER to the technical service bulletins. For spark plug tests, GO to
Pinpoint Test B.
. For ig
nition system tests, GO
to Pinpoint Test A.
.
Diff
icult to start hot
Roc
h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical
service bulletins. Check fuel pressure. For evaporative emissions components,
REFER to: Evaporative Emissions
(303
-13
Evaporative Emissions, Diagnosis and Testing).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
D iff
icult to start after hot soak
(vehicle standing after engine has reached operating temperature)
Roc h
ester valve
Injec
t
or leak
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature
(ECT) sensor
F or R
ochester
valve test,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For injector leak test, REFER to technical service bulletins. Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).

F
or evaporative emissions components,
REFER to: Evaporative Emissions
(30
3-13
Evaporative Emissions, Diagnosis and Testing).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Engine stalls
soon after start
F
uel pump relay
ECM relay


Harness damage Fue

l pump
Engine coolan

t temperature
(ECT) sensor
Fue
l lines
F

uel pressure regulator
Air leakage


Check f
or DTCS. For fuel pump and ECM relay
tests,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
Check fuel pressure.
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For ECT sensor tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For fuel line information,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
For intake system information,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation).
Engine hesi
tates/poor acceleration
Fue
l pump
Air leakage


F

uel pressure regulator
Fue

l lines
Harness damage Throttl

e sensors
Throttl

e motor
Spark

plugs fouled, gapped
incorrectly
Ignition coil
failure(s)
Check f

or water ingress into
spark plug wells
HT sho
rt to ground (tracking)
check rubber boots for cracks/damage
Exhaus
t gas recirculation (EGR)

(SC only)
Chec
k fuel pressure,
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For intake system information,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation). For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(30
3-04

Fuel Charging and Controls, Diagnosis and Testing).
For fuel lines information,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For throttle position se nsor and throttle motor
relay tests,
REFER to: Electronic Engine Controls
(30
3-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
For spark plug tests, GO to Pinpoint Test B.
.
For ign
ition system tests, GO to Pinpoint Test
A.
. F
or EGR information,
REFER to: Engine Emission Control
(30
3-08
Engine Emission Cont rol, Description and
Operation).
Engine ba
ckfires
Fue
l pump
Fue

l lines
Air leakage


Mass ai

r flow (MAF) sensor
Spark plugs


Check f

or water ingress into
spark plug wells
HT sho
rt to ground (tracking)
check rubber boots for cracks/damage
Chec
k fuel pressure,
REFER to: Fuel System Pressure Check
(31
0-
00 Fuel System - Genera l Information, General
Procedures).
For fuel pump and lines,
REFER to: Fuel Tank and Lines
(31
0-01 Fuel
Tank and Lines, Description and Operation).
For intake system,
REFER to: Intake Air Distribution and Filtering

(30
3-12 Intake Air Distribution and Filtering,
Description and Operation). For MAF sensor tests,

Diagnostic Trouble Code (D
TC) index
D
iagnostic Trouble Code (DTC) Index
DT

C
De
scription
Possib
le Source
Acti
on
P0300Ran

dom misfire detected
ECM t
o ignition coil primary circuit
faults (cylinder misfire detected
DTCs also logged)
Ignition coil
ground circuit; open
circuit, high resistance
F
uel injector circuit fault(s)
(injector DTCs also logged)
Ignition coil
failure(s)
Check f

or water ingress into spark
plug wells
HT sho
rt to ground (tracking)
check rubber boots for
cracks/damage
Spark plug
failure/fouled/incorrect
gap
Cy
linder compression low
F

uel delivery pressure (low/high)
F

uel injectors restricted/leaking
Fuel contamination


P

AS pulley bolts loose (see Service

Actions)
W
orn camshaft/broken valve
springs
For ign
ition system tests,GO
to Pinpoint Test A.
. For
inje
ctor circuit tests,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Description and Operation).
Check compressions. For
spark plug tests,GO to
Pinpoint Test B.
.
Check fuel
pressure,
REFER to: Fuel System
Pressure Check (31
0-00 Fuel
System - General
Information, General
Procedures).
For fuel injectors,
REFER to: Fuel Charging and
Controls (30
3-04 Fuel
Charging and Controls,
Diagnosis and Testing).
For fuel tank and lines
information,
REFER to: Fuel Tank and
Lin
es

(310-01 Fuel Tank and
Lines, Description and
Operation).
Check PAS pulley bolt torque
(REFER to technical service
bulletins). For engine
information,
REFER to: Specifications

(3
03-01 Engine,
Specifications).
P0301Misfire
detected, Cyl 1
R
EFER to possible sources for P0300
R
EFER to actions for P0300.
P0302Misfire

detected, Cyl 3
P0303Misfire

detected, Cyl 5
P0304Misfire

detected, Cyl 7
P0305Misfire

detected, Cyl 2
P0306Misfire

detected, Cyl 4
P0307Misfire

detected, Cyl 6
P0308Misfire

detected, Cyl 8
P0351Igni

tion coil primary/secondary circuit
malfunction, cyl 1
ECM to
ignition module primary
circuit open circuit, short circuit to
ground, high resistance
Igni
tion module to ignition coil
primary circuit open circuit, short
circuit to ground, high resistance
Ignition modu
le ground circuit
open circuit, hi gh resistance
Ignition coil
failure
Ignition modul

e failure
F
or ignition circuit tests,GO to

Pinpoint Test A.
.
P0352Igni
tion coil primary/secondary circuit
malfunction, cyl 3
P0353Igni
tion coil primary/secondary circuit
malfunction, cyl 5
P0354Igni
tion coil primary/secondary circuit
malfunction, cyl 7
P0355Igni
tion coil primary/secondary circuit
malfunction, cyl 2
P0356Igni
tion coil primary/secondary circuit
malfunction, cyl 4
P0357Igni
tion coil primary/secondary circuit
malfunction, cyl 6
P0358Igni
tion coil primary/secondary circuit
malfunction, cyl 8
P1313Misfire rate
catalyst damage, Right-hand
cylinders. NOTE. This DTC will flag only
when accompanied by a random or
individual cylinder misfire DTC; P0300,
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-
P0308.

Pinpoint Tests
P0301 t
o P0304
P1314M
i
sfire rate catalyst damage, Left-hand
cylinders. NOTE. This DTC will flag only
when accompanied by a random or
individual cylinder misfire DTC; P0300 to
P0308
P1316M i
sfire excess emission. NOTE. This DTC
will flag only when accompanied by an
individual cylinder misfire DTC; P0300 to
P0308
P1367Ignit i
on monitor (ignition module 1)
Ignition modu
le

1 disconnected
Ignition modul e
1 to ECM circuits
open circuit, short circuit to ground
or short circuit to B+ voltage
Ignition modul e
1 ground circuit
fault
Ignition coil relay fai
lure
Ignition coil open/short

circuit
Ignition module

1 failure
F
o
r ignition circuit tests,GO to

Pinpoint Test A.
.
P1368Igniti
on monitor (ignition module 2)
Ignition modu
le

2 disconnected
Ignition modul e
2 to ECM circuits
open circuit, short circuit to ground
or short 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
F
o
r ignition circuit tests,GO to

Pinpoint Test A.
.
PINPOINT TES
T A : DTC P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358;
RANDOM MISFIRE DETECTED, COIL PRIMARY/SECONDARY CIRCUIT MALFUNCTION
• NO
TE: Unless multiple cylinder misfires are apparent, only on
e circuit will normally need to be tested. The DTC set will
indicate which cylinder is misfiring.
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
A1
: CH
ECK COIL FUNCTI
ON BY SUBSTITUTION
Swap the suspect coi l
for a known good unit.
1
CLEAR t
h
e DTC. TEST the syst
em for normal operation.
2
Do
es the same DTC reoccur? The DTC will indicate if the same cylinder is misfiring.
Yes GO to A2
.
No
INST
ALL a new coil.
REFER to: Ignition Coil
-On-Plug
LH

(30
3-07 Engine Ignition, Removal and Installation) /
Ignition Coil
-On-Plu g
RH

(30
3-07 Engine Ignition, Removal and Installation).
CLEAR the DTC. TEST the system for normal operation.
A2: CHECK THE IGNIT
ION COIL SUPPLY VOLTAGE
Disc
onne
ct the relevant ignition
coil electrical connector(s).
1
Turn the ignition swit
ch to the ON
position.
2
Measure the voltage between:
Cyl 1 PI18, pin
1 (PW) and GROUND
Cy
l 2 PI22, pin
1 (PW) and GROUND
Cy
l 3 PI19, pin
1 (PW) and GROUND
Cy
l 4 PI23, pin
1 (PW) and GROUND
Cy
l 5 PI20, pin
1 (PW) and GROUND
Cy
l 6 PI24, pin
1 (PW) and GROUND
Cy
l 7 PI21, pin
1 (PW) and GROUND
Cy
l 8 PI25, pin
1 (PW) and GROUND
3
Is
t
he voltage less than 10.5 volts?
Yes REPAIR the relevant ignition coil su pply voltage circuit. This circuit includes the ignition coil relay and
ignition modules. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the

PINPOINT TEST B : CHECK SPARK PLUG
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
B1
: CH
ECK SPARK PLUG
•
NOTE
: Some spark plug types cannot
be regapped and must be replaced.
Re
move the suspect spark plug(s).
REFER to: Spark Plugs
(30
3-07 Engine Ignition,
Removal and Installation).
1
Visuall
y inspect the spark plug for cracks, damage,
carbon buildup or wet fouling, check the condition
of the ground electrode, the center electrode tip and the spark plug HT contact and confirm that the
spark plug gap is correctly set usin g a wire gauge taking care not to cause damage to the center or
ground electrode tips.
REFER to: Specifications
(30
3-07 Engine Ignition, Specifications).
2
Is th
e s
park plug condition good,
and the spark plug gap correct ?
Yes Check ignition coil and circuits. See possible sources list for misfire.
No Install a new spark pl ug(s) as required.
REFER to: Spark Plugs
(30
3-07 Engine Ignition, Removal and Installation).
CLEAR the DTC. TEST the syst em for normal operation.

Engine Igni
tion - Ignition Coil-On-Plug LH
Re
moval and Installation
Remov

al
Installation
1. Disc
onnect battery ground cable (IMPORTANT, see SRO
86.15.19 for further information).

2. Re
move the coolant expansion tank for access.
R

emove screw.
Position tank aside an

d secu
re with suitable tie.

3. Re
move coil on-plug cover.
R

emove six bolts.
R

emove cover.
Cle

an mating faces.

4. D
etach harness from retain
ing clips as necessary and
disconnect relevant coil connector.

5. R
emove relevant ignition coil.
Re

move bolts.
Re

move coil.