fuel regulator JAGUAR X308 1998 2.G User Guide

(ECT) se
nsor
Blocked part-load breather
(s
ervice action S474)
Injec
t
or leak
Engine stalls
soon
after start
F
u
el pump relay
ECM relay Thr
o
ttle contaminated
CMP/CKP sen
s
or
synchronization malfunction
Harness Fuel
pump
MAF
s
ensor malfunction
Engine coolan
t
temperature
(ECT) sensor
Fue l
lines
Air leakage Fu

el pressure regulator
F
o
r fuel pump relay tests,
GO to Pinpoint Test E.
.
F or ECM
relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
Check bull etins for throttl
e cleaning procedure. For

CMP/CKP sensor tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
Chec k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F or MAF sensor and
ECT sensor tests,
REFER to Section 303
-14 Electronic En
gine
Controls.
For fuel l
ine information,
REFER to Section 310
-01
Fuel Tank and Lines
.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
F o
r fuel pressure regulato
r check, GO to Pinpoint
Test D.
.
Engine 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 sho
rt to ground (tracking)
check rubber
boots for
cracks/damage
ECM failu r
e
Chec
k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F o
r 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 and throttle motor relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
For ign i
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Contact dealer techn i
cal
support for advice on
possible ECM failure.
Engine ba ckfiresFuel
pump
Air leakage MAF s
e
nsor
HO2 sensors Spark plugs
Check fo
r water ingress into
spark plug wells
HT short to ground (tracking) check rubber
boots for
cracks/damage
Ignition coil fail
ure(s)
Chec
k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Ge
n
eral
Informati
o
n
.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
For MAF and HO2
sensor circuit tests,
REFER to Section 303
-14 Electronic En
gine
Controls.
For igni
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Engine
s
urges
Air leakage Fue
l
pump
Stop lamp swi
t
ch
MAF s
e
nsor
Harness Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress into
spark plug wells
HT sho rt to ground (tracking)
check rubber
boots for
cracks/damage
ECM failu r
e
F
or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution
and F
ilt
ering
.
Chec k fu
el pressure,
REFER to Section 310
-00 Fu
el System
- Gen
e
ral
Informati
o
n
.
F or stop l
amp switch in
formation, refer to the
wiring diagrams. For MAF se nsor, throttle position
sensor and throttle motor relay tests,
REFER to Section 303
-14 Elec tronic En
gine
Controls.
For ign i
tion system,
REFER to Section 303
-07 En
gine Ignition
.
Contact dealer techn i
cal
support for advice on
possible ECM failure.

Default mode Definitions

MECH
ANICAL LIMP-HOME MODE:

No el
ectronic throttle operation (mechanical
operation for last quarter of pedal travel)
M
aximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine
speed restricted to 3000
rpm maximum, by fuel cut-off
Hi
gh idle speed (1200 rpm approx.)
Misfire

at idle, due to cylinder cut as a means of control
ling idle speed (the misfire will switch cylinders, as the
strategy varies th e cylinder cut)
Cruise (speed) contr
ol inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
El
ectronic throttle operation, limited to maximum 25°
Cruise (speed) contr

ol inhibited
• NOTE: The throttle oper ation uses the same map as for reverse gear.
ENGINE SPEED LIMIT:
Engine
runs normally, up to 3000 rpm
Engine

speed restricted to 3000
rpm maximum, by fuel cut-off
Cruise (speed) contr
ol inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contr
ol inhibited
R

everse throttle pr
ogression engaged at second occurrence of DTC flagging
Diagnostic Trouble Code (D
TC) index
DT
C
Cond
ition
P
ossible Causes
Acti
on
P0171Right-hand cylinders combustion too

leanAir
intake leak between MAF
sensor and throttle
F
uel filter system blockage
F

uel injector blockage
F

uel pressure regulator failure (low

fuel pressure)
Low f
uel pump output
H0

2S harness wiring fault
E

xhaust leak (before catalyst)
ECM receivi

ng incorrect signal from

one or more of the following
sensors - ECT, MAF, IAT, TP.
Fo
r intake system,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
F
or fuel filter,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors. Check the
fuel pressure regu lator. Check fuel
pressure. For HO2S circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
F
or exhaust information,
REFER to Section 309
-00
Exhaust
Sy

stem
.
For se
nsor circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
P0172Right-hand cylinders combustion too

ri
ch
Engine
misfire
Bl

ocked air filter
F

uel system return blockage
Leak

ing fuel injector(s)
F

uel pressure regulator failure
(high fuel pressure)
ECM receivi
ng incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
Chec
k for 'engine misfire detected'
DTCs. Check the air filter element,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
Chec
k the fuel lines,
REFER to Section 310
-01
Fuel Tank
and Lines.
Chec
k the fuel injectors,
REFER to Fuel Injectors
- in t
his
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
.
Check the fuel
pressure,

REFE
R to Section 310
-00
Fu
el
Sy
ste
m
- General

Information
.
Check f o
r DTCs indicating a sensor
fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0174
Left-hand cyl i
nders combustion too
lean
Air in
take leak between MAF
sensor and throttle
F u
el filter system blockage
F
u
el injector blockage
F
u
el pressure regulator failure (low

fuel pressure)
Low f u
el pump output
H0
2S harness wiri
ng fault
E
x
haust leak (before catalyst)
ECM receivi
n
g incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
F o
r air intake sy
stem information,
REFER to Section 303
-12 Int
ake Air

Distribu tion and Filterin
g
.
Check the fuel fi lter,
REF
ER to Section 310
-01
Fu
el Tank
and Lines.
Chec k the
fuel injectors,
REFER to Fuel Injectors
- in t h
is
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
. Ch
eck the fuel
pressure,
REFER to Section 310
-00 Fu
el
Sy
ste
m
- General

Information
.
Check f o
r DTCs indicating which HO2

sensor is faulty,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
Check f o
r DTCs indicating a sensor
fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0175Left-hand cyli

nders combustion too
rich
Engine m
isfire
Bl
ocked air
filter
F
u
el system return blockage
Leak
i
ng fuel injector(s)
F
u
el pressure regulator failure
(high fuel pressure)
ECM receivi n
g incorrect signal from

one or more of the following sensors - ECT, MAF, IAT, TP
Check for 'en
gine misfire detected'
DTCs. Check the air filter element,
REFER to Section 303
-12 Int
ake Air

Distribu tion and Filterin
g
.
Chec k the
fuel lines,
REFER to Section 310
-01 Fu
el Tank
and Lines.
Chec k the
fuel injectors,
REFER to Fuel Injector
- Vehicles Wi
thout: Supercharger
/

Fue
l Injector
- Ve
hicles With
:
Supercharger
in this
section.
For fuel pressure regulator check,GO
to Pinpoint Test D.
. Check for DT
Cs
indicating a sensor fault,
REFER to Section 303
-14 El
ectronic
Engine
C
ontrols
.
P0201F
u
el injector circuit malfunction, Cyl

1
Injector discon n
ected
Inject
or wir
ing open or short circuit

Injector fail
ure
F
o
r fuel injector circuit tests,GO to
Pinpoint Test A.
.
P0202Fu
el injector circuit malfunction, Cyl

3
P0203F u
el injector circuit malfunction, Cyl

5
P0204F u
el injector circuit malfunction, Cyl

7
P0205Fu
el injector circuit malfunction, Cyl

2
P0206Fu
el injector circuit malfunction, Cyl

4
P0207F u
el injector circuit malfunction, Cyl

6
P0208F u
el injector circuit malfunction, Cyl

8
P0300Ran d
om misfire detected
ECM t
o
ignition coil primary circuit
faults (cylinder misfire detected DTCs also logged)
Ignition coil ground circuit; open
ci
rcuit, high resistance
F
u
el injector circuit fault(s)
(injector DTCs also logged)
F o
r ignition circuit tests,
REFER to Section 303
-07 En
gine
Ignition.
F or engi
ne information,
REFER to Section 303
-00 En
gine
Sy
ste
m
- General

Information
.
F o
r fuel injector circuit tests,GO to

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.

Fuel Char
ging and Controls - Fu
el Injection Supply Manifold RH
Remo
val and Installation
Remov
a
l
1.
Re
move fuel injectors; refer to (SC) 18.10.01.

2. Disc
onnect fuel pressure regulator.
1. Remove bolts.
2. Reposition pres sure regulator.
Disc
ard O-ring.

3. Re
move fuel rail from charge air cooler adaptor.
1. Remove three bolts.
2. Remove fuel rail; still co nnected to fuel crossover pipe
and fuel return pipe.

4. Re
move fuel rail from fuel cross-over pipe.
1. Remove bolt.
2. Discard O-ring.

5. Re
move fuel rail to charge air cooler adaptor seals.
1. Discard seals.
2. Clean and inspect mating faces.

I
nstallation


1.
Inst
all new seals between fuel rail and charge air cooler
adapter, ensuring they are fully seated.

2. Install
fuel rail to fuel cross-over pipe.
1. Install new O-ring and lubricate with petroleum jelly.
2. Install bolt.

3. Install
fuel rail to charge air cooler adaptor.
1. Align fuel rail to adaptor; still connected to fuel crossover pipe and fuel return pipe. Locate fuel rail
into adaptor.
2. Install three bolts which se cure fuel rail to adaptor.
Tighten to 18-24 Nm.

4. Install
fuel pressure regulator.
Install a new O-r

ing to fu
el pressure regulator and
lubricate with petroleum jelly
1. Install bolts.
5. Install fuel injectors; refer to (SC) 18.10.01.

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,

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.
REF E
R 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.
.
Engine s
urges
Air leakage
Fue
l
pump
Fue
l
lines
Mass ai
r fl
ow (MAF) sensor
Harness damage Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress into
spark plug wells
HT short to ground (tracking) check rubber
boots for
cracks/damage
Fo r
intake system,
REFER to: Intake Air Distribution and Filtering

(30 3
-12 Intake Air Distribution and Filtering,
Description and Operation). Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
For fuel pump and lines,
REFER to: Fuel Tank and Lines
(310
-01 Fuel
Tank and Lines, Description and Operation).
For MAF sensor, throttle position sensor and
throttle motor relay 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.
.
Engine detonates/k
nocks
Fue
l
lines
F
u
el pressure regulator
Air leakage
Mass air fl
ow (MAF) sensor
O
xygen senso
rs
Fue
l
pump
F
o
r fuel lines,
REFER to: Fuel Tank and Lines
(310
-01 Fuel
Tank and Lines, Description and Operation).
For fuel pressure regulator,
REFER to: Fuel Charging and Controls
(303
-04

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

(30 3
-12 Intake Air Distribution and Filtering,
Description and Operation).
For MAF sensor and oxyg en sensor tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Check fuel pressure,
REFER to: Fuel System Pressure Check
(310
-
00 Fuel System - Genera l Information, General
Procedures).
No t
hrottle response
Throttl
e
sensors
Throttl
e
motor
Fo
r th
rottle position sensor tests, throttle
motor relay tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
Poor throttle responseThrottl e
sensors
Throttl
e
motor
Air leakage Mass air fl

ow (MAF) sensor
F
or throttl
e position se
nsor and throttle motor
relay tests,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).
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,
REFER to: Electronic Engine Controls
(303
-14
Electronic Engine Co ntrols, Diagnosis and
Testing).

Engine Emission
Control - Engine Emission Control
D
iagn
osis and Testing
I
n
spection and Verification
1.
1. Veri fy the customer concern.
2. 2. Vis
ually inspect for obvious signs of mechanical
or electrical damage, correct fitment, etc.
Vi
sual Inspection Chart
3.
3. Veri fy the foll
owing syst
ems are working correctly:
Air intake
system
Coo
ling system

Charging system
Fu
el charging system
Ignition sys
t
em
4. 4. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding
to the next step
5. 5. 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).
6. 6. 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.
7. 7. 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.
• 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
Engi
ne
oil level
Coo
ling system coolant level

Fue
l
level
Fuel contaminatio
n
/
grade/quality
Throttle body Poly
-ve
e belt
Engine breath
er
system
pipework/connections
EGR pipework
condition (cracking, etc)
F
u
ses
W
i
ring harness
E
l
ectrical connector(s)
Sens
o
r(s)
Engine
control module (E
CM)
Sy
m
ptom
(general)
S y
mptom (specific)
Possib
l
e source
Acti
o
n
Poor
dr iveabilityEngine h e
sitates/poor
acceleration
Fue l
pump
Air leakage F
u
el pressure regulator
Chec
k fu
el pressure,
REFER to Section 310
-00 Fu
el
Sy
ste
m
- General Informati
on.

Diagnostic Trouble Code (D
TC) Index
Pinpoint Tests
Fue
l lines
Harness damage


Throttl

e sensors
Throttl

e motor
Spark plugs

fouled
Ignition coil

failure(s)
HT sho

rt to ground (tracking) check
rubber boots for cracks/damage
Exhaus
t gas recirculation (EGR)
F
or air intake syst
em information,
REFER to Section 303
-12
Intake Air

Distribu
tion and Filtering
.
F
or fuel pressure
regulator tests,
REF
ER to Section 303
-04
Fuel
Charging and Con

trols
.
F
or fuel line information,
REFER to Section 310
-01
Fuel Tank

and Lines.
F
or throttle sensor
circuit tests,
REFER to Section 303
-14
Electronic
Engine

Controls
.
Fo
r throttle motor
circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
For ign
ition system tests,
REFER to Section 303
-07
Engine
Ignition.
Inspe
ct EGR components, for circuit
tests, GO to Pinpoint Test A.
.
DT
C
De
scription
Possib
le Source
Acti
on
P0400Exhaus

t gas
recirculation (EGR) flow malfunction
EGR
valve connector pins high
resistance
EGR pipe/exhaust manifold leak EGR pipe block
ed
EGR val

ve stuck open/closed,
blocked
EGR
valve failure
Check the EGR pi
pe, valve and manifold for
leaks/blockages. Check the EGR valve function.
For EGR valve circuit tests,GO to Pinpoint Test A.
.
P0405Exhaus
t gas
recirculation (EGR) drive
circuits open circuit
EGR valve power supply circuit o
pen circuit
EGR valve t

o ECM drive circuit
pair - EGR pins 1/3, 4/6 open circuit, high resistance
EGR val
ve failure (stepper motor
open circuit)
F
or EGR valve circuit tests,GO to Pinpoint Test
A.
.
P0406Exhaus
t gas
recirculation (EGR) drive
circuits short circuit
EGR valve t
o ECM drive circuit
pair - EGR pins 1/3, 4/6 short
circuit to ground or high voltage
EGR val
ve failure (stepper motor
short circuit)
F
or EGR valve circuit tests,GO to Pinpoint Test
A.
.
P
INPOINT TEST A : DTC P0400, P0405; EGR VALV
E FLOW MALFUNCTION/DRIVE CIRCUITS OPEN
CIRCUIT
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1: CHECK

THE EMS POWER SU
PPLIES TO THE EGR VALVE
D
isconnect the EGR valve electrical connector, PI34.
1
Turn the ignition swi

tch to the ON
position.
2
Make sure the EMS re lay i
s energized.
Vehicles with AJ26 engine:
Me
asure the voltage between PI34, pins 02 and 05 (WP) and GROUND
Vehicles with AJ27 engine:
Me
asure the voltage between PI34, pins 02 and 05 (WU) and GROUND
3
Is th

e voltage at either pin less than 10 volts?
Yes