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
E
vaporative Emissions - Evaporative Emissions
D
iagnosis and Testing
Prelim
inary Inspection
1.
1. Vis
ually inspect for obvious signs of mechanical or electrical damage.
V
isual Inspection Chart
2.
2. If
an obvious cause for an observed or
reported concern is found, correct th e cause (if possible) before proceeding
to the next step.
3. 3. If the concern is not visually evident, verify the symptom and proceed with diagnosis, using the Jaguar approved
diagnostic system, where available.
4. 4. Where K-Line or Vacutec equipment is available, it should be used as an aid to diagnosis. The equipment must be
capable of testing to the 0.020 thou standard (2001 MY on).
Diagnostic Drive Cycles
Following th
e setting of a DTC, the appropriate repairs must
be carried out, and the normal operation of the system
checked. This will be done by performing a series of drive cycles which will enable the vehicle to operate the evaporative
emissions system as a function check. For details of the drive cycles,
REFER to Section 303
-1
4 Electronic Engine Controls
.
ECM adapt
ations.
Diagnostic Trouble Code
(D
TC) index/Symptom Chart
1.
1. Wh
ere 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).
2. 2. 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.
3. 3. 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.
MechanicalElectrical
Engi
ne oil level
Coo
ling system coolant level
Fue
l level
Fuel contaminatio
n
/grade/quality
Throttle body Poly
-vee belt
F
uses
W
iring harness
E
lectrical connector(s)
Sens
or(s)
Engine
control module (ECM)
Driver Info
rmation
•
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: A trip is an ignition OFF, 30 seconds delay, ignition ON cycle, plus a minimum coolant temperature increase of 22°
C (40°F) after which the coolant temperat ure should reach a minimum 71°C (160°F)
Diagnostic Trouble C
ode (DTC) index
Sy
m
ptom
Possib
l
e Source
Acti
o
n
D
i
fficulty in filling
R
e
striction in the vapor line between the fuel tank and the
carbon canister outlet/atmospheric port
Check f or free f
low of air.
F
u
el smell
Adaptat
i
ons incomplete
Cani
st
er purge valve inoperative
Carry
o
ut the adaptations
procedure,
REFER to Section 303
-14 Ele c
tronic Engine Controls
.
Chec k cani
ster purge valve
operation.
M e
ssage center display
(see below)
Fue l
filler cap missing/not
tightened after refuelling
Check fu
el filler cap condition
and fitment.
Warning Li
ght
Mess
age Defaul
t Mode
DT
C
RedCheck Engine (after two
trip
s)
ECM de
fa
ult (canister purge inhibited, adaptive fuel
metering inhibited)
P0442,
P0444, P0445,
P0447, P0448.
Re dCheck Engine (after two
trip
s)
No
neP04 52,
P0453.
Di
agno
stic
Trouble Code
De scr
iption
Possib
l
e Source
Acti
o
n
P0442Sy
st
em leak detected
F
u
el tank filler cap seal defective
Sy
ste
m leak (c
anister damage,
pipework damage)
Cani st
er close valve leaking
F
u
el tank leak
Chec
k fi
ller cap,
system pipework,
fuel tank,GO to Pinpoint Test A.
.
F o
r fuel tank information,
REFER to Section 310
-01 Fu
el Tank
and Lines.
P0444Canist
er purge valve circuit
open circuit
Cani st
er purge valve to ECM
drive circuit; open circuit, high
resistance
Cani st
er purge valve failure
F
or purge
valve circuit tests,GO to
Pinpoint Test B.
.
P0445Canist
er purge valve circuit
short circuit
Cani st
er purge valve to ECM
drive circuit; short circuit to ground
Canist
er purge valve failure
(stuck closed)
F or purge
valve circuit tests,GO to
Pinpoint Test B.
.
P0447Canist
er close valve (CCV)
circuit open circuit.
CCV power su pply ci
rcuit; open
circuit, short circuit
CCV to ECM drive circuit;
open
circuit, high resistance, short circuit to B+ voltage
CCV failure
Fo
r CCV circuit tests,GO to Pinpoint
Test C.
.
P0448Canist
er Close Valve (CCV)
circuit short circuit
Cani st
er close valve to ECM drive
circuit; short circuit to ground
Cani st
er close valve failure
F
o
r CCV circuit tests,GO to Pinpoint
Test C.
.
P0452 Fu
el tank Pressure (FTP)
sensor circuit; low voltage (low pressure)
FTP sen
sor disconnected
FTP sen
sor to ECM sense circuit;
open circuit, short circuit to ground
FTP sens
or to ECM power supply
circuit open circuit, short circuit to ground
FT
P sensor failure
For FT
P se
nsor circuit tests,GO to
Pinpoint Test D.
.
P0453Fu
el tank Pressure (FTP)
sensor circuit; high voltage
(high pressure)
FTP sen
sor to ECM signal ground
circuit open circuit
F T
P sensor to ECM wiring
(supply, sense, signal ground),
short circuit to each other
FTP sen
sor to ECM sense circuit
short circuit to B+ voltage
For FT P se
nsor circuit tests,GO to
Pinpoint Test D.
.
FT
P sensor failure
Sym
ptom Chart
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
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 backfiresFuel
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.
Default mode Definitions
MECHANIC
AL LIMP-HOME MODE:
No elec
tronic throttle operation (mechanical
operation for last quarter of pedal travel)
Ma
ximum 25° throttle opening,
depending on adjustment of th rottle mechanical linkage
Engine speed restri
cted to 3000
rpm maximum, by fuel cut-off
High i
dle 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
o
l inhibited
REVERSE THROTTLE PROGRESSION ENABLED:
Elec
tronic throttle operation, limited to maximum 25°
Cruise (speed) contr
o
l 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 restri
cted to 3000
rpm maximum, by fuel cut-off
Cruise (speed) contr o
l Inhibited
LIMP-HOME UNAVAILABLE:
Cruise (speed) contro
l inhibited
R
e
verse throttle pr
ogression engaged at second occurrence of DTC flagging
Diagnostic Trouble Code (D TC) Index
Performance3000
rpm)
P03
06,
P0307, P0308, P1313, P1314
Ambe
rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to
3000 rpm)
P03 27,
P0328, P0332, P0333, P1648
Ambe
rRestri
cted
Performance
R e
verse throttle pr
ogression enabled
P1474
AmberRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to
3000 rpm)
P1230
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to
3000 rpm)
P1671
Ambe rRestri
cted
Performance
Engine
Speed Limit (runs normally, limited to
3000 rpm)
P11 12,
P1113
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1601 (SC on
ly)
AmberRestri
cted
Performance
Gearbox defau l
t to 4th gear
P16
05 (
NA only)
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P0702
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1795
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1796
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1797
Ambe
rRestri
cted
Performance
Gearbox defau l
t to 4th gear
P1605
Ambe
rNoneGearbox defau l
t to 4th gear
P0705 (SC on
ly)
Ambe
rNoneGearbox defau l
t to 4th gear
P0706
Ambe
rNoneGearbox defau l
t to 4th gear
P1720
DT
C
De
scription
Possib
le Source
Acti
on
P0101Mass ai
r flow (MAF) sensor
range/performance
Bl
ocked air filter
Air
intake leak
Engine
breather leak
Throttl
e control malfunction
MAF
sensor to ECM sensing circuit
high resistance
MAF
sensor to ECM sensing circuit
intermittent short circuit to ground
MAF
sensor supply circuit high
resistance
MAF
sensor failure
Chec
k the air filter element, check the
air intake system for leaks,
REFER to Section 303
-1
2 Intake Air
Distribu
tion and Filtering
.
Chec
k the engine breather system for
leaks,
REFER to Section 303
-08
Engine
Emissi
on Control
.
F
or throttle control circuit tests,GO to
Pinpoint Test T.
. Fo
r MAF sensor
circuit tests,GO to Pinpoint Test A.
.
P0102Mass ai
r flow (MAF) sensor sense
circuit low voltage
Bl
ocked air filter
MAF
sensor to ECM sensing circuit
high resistance or open circuit
MAF
sensor to ECM sensing circuit
intermittent short circuit to ground
MAF
sensor supply circuit open
circuit or short circuit to ground
MAF
sensor failure
Chec
k the air filter element,
REFER to Section 303
-1
2 Intake Air
Distribu
tion and Filtering
.
For MAF
sensor circuit tests, GO to
Pinpoint Test A.
.
P0103Mass ai
r flow (MAF) sensor sense
circuit high voltage
MAF
sensor to ECM reference
ground circuit open circuit
MAF
sensor to ECM sensing circuit
short circuit to high voltage
MAF sensor
failure
For MAF
sensor circuit tests,GO to
Pinpoint Test A.
.
P0106BARO ci
rcuit, low voltage
BARO f
ailure (internal ECM fault)
Contact deal
er technical support for
advice on possible ECM failure.
P0107BARO ci
rcuit, high voltage
BARO f
ailure (internal ECM fault)
Contact deal
er technical support for
advice on possible ECM failure.
P0111In
take air temperature (IAT)
sensor range/performance
Bl
ocked air filter
Air
intake leak
Engine
breather leak
IAT sensor to
ECM wiring open
circuit or high resistance
IAT se
nsor to ECM sensing circuit
short circuit to high voltage
IAT sensor fail
ure
Chec
k the air filter element, check the
air intake system for leaks,
REFER to Section 303
-1
2 Intake Air
Distribu
tion and Filtering
.
Chec
k the engine breather system for
leaks,
REFER to Section 303
-08
Engine
Emissi
on Control
.
F
or IAT sensor circuit tests,GO to
Pinpoint Test B.
.
P0112In
take air temperature (IAT)
sensor sense circuit high voltage
(low air temperature)
IAT sensor to
ECM wiring open
circuit or high resistance
IAT se
nsor to ECM sensing circuit
short circuit to high voltage
IAT sensor fail
ure
F
or IAT sensor circuit tests,GO to
Pinpoint Test B.
.
P0113In
take air temperature (IAT)
sensor sense circuit low voltage
(high air temperature)
IAT sensor to
ECM wiring short
circuit to ground
IAT sensor fail
ure
F
or IAT sensor circuit tests,GO to
Pinpoint Test B.
.
P0116E
ngine coolant temperature (ECT)
sensor range / performance
Low/contaminated coolant Therm
ostat failure
ECT se
nsor to ECM sensing circuit
high resistance when hot
ECT se
nsor to ECM sensing circuit
intermittent high resistance
ECT sensor
failure
Che
ck coolant level and condition.
Check thermostat function. For ECT
sensor circuit tests,GO to Pinpoint
Test C.
.
P0117E
ngine coolant temperature (ECT)
sensor sense circuit high voltage
(low coolant temperature)
ECT se
nsor disconnected
ECT se
nsor to ECM sensing circuit
high resistance, open circuit or
short circuit to high voltage
ECT sensor
failure
F
or ECT sensor circuit tests,GO to
Pinpoint Test C.
.
P0118E
ngine coolant temperature (ECT)
sensor sense circuit low voltage
(high coolant temperature)
Engine
overheat condition
ECT se
nsor to ECM wiring short
circuit to ground
ECT sensor
failure
Chec
k engine for overheating. For ECT
sensor circuit tests,GO to Pinpoint
Test C.
.
P0121Thro
ttle position (TP) sensor
circuit rang e/performance
TP sensor
to ECM wiring open
circuit or high resistance
TP se
nsor to ECM sensing circuits 1
or 2 short circuit to high voltage
TP sensor
failure
F
or TP sensor circ
uit tests,GO to
Pinpoint Test D.
, and G
O to Pinpoint
Test K.
.
D
iagnostic Trouble Code (DTC) Index
Ex
haust System - Front Muffler4.0L
NA V8 - AJ27/3.2L NA V8 - AJ26
Remo
val and Installation
Remov
a
l
Installation
1. Ra
ise the vehicle on a ramp.
2. Move the front muf f
ler forwar
d to allow the intermediate
mufflers to be displaced.
Slac ken t
he clamps (left-hand and right-hand sides),
catalytic converter to front muffler.
3. Slacken the clamps (left-ha nd and right-hand sides),
i
ntermediate mufflers to front muffler.
4. Remove the front muffler.
Di
sconnect the front muffler
from the intermediate
mufflers and then from the downpipe catalytic converters.
5. Clean and inspect al l ex
haust joints.
1. Fit the front muffler.
Fi
t the front muffler fully into the downpipe catalytic
converters and then slide it rearward to engage the
intermediate mufflers.
2. Correctl
y position the front muffl
er in the catalytic converters
to align the correct reference / index indicator ring..
Tigh ten th
e clamps (left-hand
and right-hand sides), front
muffler to catalytic converters.
3. Correctly position the intermedia te mufflers to the front muffler
to align the correct refere nce / index indicator ring.