Oil JAGUAR X308 1998 2.G Workshop Manual

P1122Acce
lerator pedal position (APP)
sensor circuit 'A' low voltage
A
PP sensor to ECM sense circuit
'A' (sensor pin 5) open circuit or
high resistance
Sensor power su
pply fault
APP s

ensor failure
For APP
sensor circuit tests,GO to
Pinpoint Test R.
, andG
O to Pinpoint
Test S.
.
P1123Acce
lerator pedal position (APP)
sensor circuit 'A' high voltage
A
PP sensor to ECM sense circuit
'A' (sensor pin 5) short circuit to
high voltage
APP s
ensor failure
For APP
sensor circuit tests, GO to
Pinpoint Test R.
, and G
O to Pinpoint
Test S.
.
P1221Acce
lerator pedal position (APP)
sensor circuit 'B'
range/performance
A
PP sensor to ECM sense circuit
'B' (sensor pin 3) open circuit,
short circuit or high resistance
Sensor power su
pply fault
Sensor r

eference ground fault
APP s

ensor failure
For APP
sensor circuit tests,GO to
Pinpoint Test R.
, andG
O to Pinpoint
Test S.
.
P1222Acce
lerator pedal position (APP)
sensor circuit 'B' low voltage
A
PP sensor to ECM sense circuit
'B' (sensor pin 3) open circuit or
high resistance
Sensor power su
pply fault
APP s

ensor failure
For APP
sensor circuit tests,GO to
Pinpoint Test R.
, andG
O to Pinpoint
Test S.
.
P1223Acce
lerator pedal position (APP)
sensor circuit 'B' high voltage
A
PP sensor to ECM sense circuit
'B' (sensor pin 3) short circuit to
high voltage
APP s
ensor failure
For APP
sensor circuit tests,GO to
Pinpoint Test R.
, andG
O to Pinpoint
Test S.
.
P1224Throttl
e control position error
Thro
ttle position adaptations not
performed after ba ttery disconnect
TP se
nsor disconnected
TP se

nsor to ECM sense circuits
open circuit, hi gh resistance
Throttl
e motor power relay failure
Throttl

e motor power relay to ECM
circuit fault
Throttl
e motor power relay power
supply open circuit
ECM ground circuit faul
t (relay coil
drive)
Th
rottle motor to ECM drive circuits

open circuit, short circuit, high
resistance
Throttl
e motor failure
Throttl

e assembly failure
Carry
out throttle adaptation
procedure. For TP sensor circuit
tests,GO to Pinpoint Test D.
, andG
O
to Pinpoint Test K.
. F
or throttle motor

circuit tests,GO to Pinpoint Test T.
.
F
or throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1226Mechanica

l guard sensor
range/performance
Mechanica
l guard sensor to ECM
sense circuit open circuit, short
circuit or high resistance
Sensor power su
pply fault
Sensor r

eference ground fault
Mechanica

l guard sensor failure
Mechanica

l guard actuator
seized/spring broken
For mech
anical guard circuit tests,GO
to Pinpoint Test U.
. F
or sensor power
supply circuit tests,GO to Pinpoint
Test V.
. F
or sensor ground circuit
tests,GO to Pinpoint Test W.
. For
throttle body i
nformation,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1227Mechanica

l guard sensor circuit
low voltage
Mechanica
l guard sensor to ECM
sense circuit open circuit or high
resistance
Sensor power su
pply fault
Mechanica

l guard sensor failure
For mech
anical guard circuit tests,GO
to Pinpoint Test U.
. F
or sensor power
supply circuit tests,GO to Pinpoint
Test V.
. F
or throttle body
information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1228Mechanica

l guard sensor circuit
high voltage
Mechanica
l guard sensor to ECM
sense circuit short circuit to high
voltage
Mechanica
l guard sensor failure
For mech
anical guard circuit tests,GO
to Pinpoint Test U.
. F
or throttle body
information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1229Throttl

e motor control circuit
mallfunction
Throttl
e motor disconnected
Th

rottle motor to ECM drive circuits

short circuit or open circuit
Throttl
e motor failure
Fo
r throttle motor circuit tests,GO to
Pinpoint Test T.
.
P1230Fue
l pump relay malfunction.
NOTE. This DTC covers the S/C
system fuel pump 1
F
uel pump relay failure
F

uel pump to ECM circuit fault
F

uel pump relay coil power supply
F
or fuel pump relay circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.

op
en circuit
ECM ground circuit faul
t (relay coil

drive)
P1235Vacuu m
switching valve (VSV) 1
circuit range/ performance
(mechanical guard position)
Vac u
um leak/blockage between the

throttle elbow and the throttle
vacuum actuator
Vacuu m
actuator failure
Mechanica
l
guard actuator
seized/spring broken
Carr y out mechanical checks
for
vacuum leak/blockag e, failed vacuum
actuator, and broken /siezed actuator
spring.
P1236Vacuu m
switching valve (VSV) 1
(vacuum) circuit failure
VSV 1 disconne cted

VSV 1 to ECM drive circu
i
t high
resistance, open circuit or short
circuit
VSV 1 powe r supply open
circuit
VSV 1 failu
r
e
For VSV tests,

REF
ER to Section 310
-03
Sp
eed
Control.
P1237Vacuu
m
switching valve (VSV) 2
(atmosphere) circuit failure
VSV 2 disconne cted

VSV 2 to ECM drive circu
i
t high
resistance, open circuit or short
circuit
VSV 2 power supply open
circuit
VSV 2 failu
r
e
For VSV tests,

REF
ER to Section 310
-03
Sp
eed
Control.
P1238Vacuu
m
switching valve (VSV) 3
(release) circuit failure
VSV 3 disconne cted

VSV 3 to ECM drive circu
i
t high
resistance, open circuit or short
circuit
VSV 3 powe r supply open
circuit
VSV 3 failu
r
e
For VSV tests,

REF
ER to Section 310
-03
Sp
eed
Control.
P1240Sensor r
e
fere
nce voltage
malfunction (throttle sensors, fuel
tank pressure se nsor) (ECM pins
EM10-21; EM11-8)
ECM t o
sensors reference voltage
short circuit to ground, short circuit
to high voltage, op en circuit, high
resistance
TP sensor , pedal position and
mechan
ical guard sensor(s), fuel
tank pressure sens or failure(s)
Fo
r sensor reference voltage circuit
tests,GO to Pinpoint Test V.
.
P1241Sensor re
ferenc
e voltage low
(throttle sensors, fuel tank
pressure sensor) (ECM pins EM10-
21; EM11-8)
ECM t o
sensors reference voltage
short circuit to ground
TP sensor , APP
and mechanical
guard sensor(s), fuel tank pressure
sensor failure(s)
F o
r sensor reference voltage circuit
tests,GO to Pinpoint Test V.
.
P1242Sensor re
ferenc
e voltage high
(throttle sensors, fuel tank
pressure sensor) (ECM pins EM10-
21; EM11-8)
ECM t o
sensors reference voltage
circuit open circuit, high resistance,
short circuit to high voltage
TP sensor , APP
and mechanical
guard sensor(s), fuel tank pressure
sensor failure(s)
F o
r sensor reference voltage circuit
tests,GO to Pinpoint Test V.
.
P1243Sensor re
ference ground
malfunction (throttle sensors, fuel
tank pressure sensor, ECT sensor,
IAT sensor, IAT sensor 2) (ECM
pins EM10-20; EM11-12)
ECM t o
sensors reference ground
circuit open circuit, high resistance
Throttle sensors, fuel
tank pressure

sensor, ECT sensor, IAT sensor,
IAT sensor 2 failures
F o
r sensor reference ground circuit
tests,GO to Pinpoint Test W.
.
P1245Engine crank signal low voltage Starter relay coi
l to ECM/BPM
circuit open circuit
For en gin
e crank circuit tests,GO to
Pinpoint Test X.
.
P1246Engine crank signal high voltage Starter relay coi
l to ECM/BPM
circuit short circuit to B+ voltage
B P
M failure
For en
gin
e crank circuit tests,GO to
Pinpoint Test X.
.
P1250Engine load
malfunction
Air in
take leak
Engine breath

er leak
TP sens

or circuit fault (DTC P0121)

Throttle
valve spring failure
Check air i
ntake system for leaks,
REFER to Section 303
-12
Intake Air
Distribution and Filterin

g
.
Check engi
ne breather system for
leaks,
REFER to Section 303
-08 En
gine
Emissi
on Control.
Se e
pinpoint test for P0121. For
throttle body information,
REFER to Section 303
-04 Fu
el
Charging and Con
t
rols
.
P1251Thr
o
ttle position malfunction
(engine off)
TP sensor to ECM wiri
ng open
circuit or high resistance
F o
r TP sensor circ
uit tests,GO to
Pinpoint Test D.
, andGO to Pinpoint

TP se
nsor to ECM sensing circuits
('1' or '2') short circuit to high
voltage
TP sensor
failure
Throttl

e motor disconnected
Th

rottle motor to ECM drive circuits

short circuit or open circuit
Throttl
e motor failure
Throttl

e assembly failure
Test
K. . F
or throttle motor circuit
tests,GO to Pinpoint Test T.
. For
throttle body i
nformation,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1252Mec

hanical gu
ard position
malfunction (cruise (speed)
control)
VSV 1, 2, 3 v
acuum and/or
electrical circuit fault(s) open
circuit, short circuit or high
resistance
Mechanica
l guard sensor to ECM
sense circuit
Mechanica
l guard sensor failure
Mechanica

l guard actuator
siezed/spring broken
Throttl
e vacuum actuator fault
Se
e pinpoint tests for components
listed.
P1253Mec
hanical gu
ard position
malfunction (engine off)
VSV 1, 2, 3 v
acuum and/or
electrical circuit fault(s)
Mechanica
l guard sensor to ECM
sense circuit
Mechanica
l guard sensor failure
Mechanica

l guard actuator
siezed/spring broken
Throttl
e vacuum actuator fault
Se
e pinpoint tests for components
listed.
P1260Se
curity input malfunction
K
TM to ECM circuit short circuit,
high resistance or open circuit
KTM failu
re
F
or KTM circuit tests,GO to Pinpoint
Test Y.
.
P1313M
isfire rate catalyst damage,
right-hand. NOTE: This DTC will
flag only when accompanied by a
random or individual cylinder
misfire DTC; P0300, P0301 to
P0304
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-P0308.
P1314Mi

sfire rate catalyst damage, left-
Hand: NOTE. This DTC will flag
only when accompanied by a
random or individual cylinder
misfire DTC; P0300 to P0308
P1316M
isfire excess emission. NOTE:
This DTC will flag only when
accompanied by an individual
cylinder misfire DTC; P0300 to
P0308
P1336Cranksh
aft position
(CKP) sensor /
camshaft position (CMP) sensor
synchronization malfunction
CKP s
ensor/CMP sensor
disconnected
CKP sensor/CM
P sensor gap
incorrect/foreign matter on sensor
face
CKP s
ensor/CMP sensor sensing
circuit open circuit, short circuit to
ground, short circuit to high
voltage
CKP s
ensor/CMP sensor failure
F
or CKP sensor circ
uit tests,GO to
Pinpoint Test N.
. For CM
P sensor
circuit tests,GO to Pinpoint Test O.
.
P1367Ignit
ion 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 failure
Ignition coil

open/short circuit
Ignition modul

e 1 failure
F
or ignition circuit tests,
REFER to Section 303
-07
Engine
Ignition.
P1368Ignit

ion monitor (ignition module
2)
Ignition modu
le
2 disconnected
Ignition modul
e 2 to ECM circuits
open circuit, short circuit to ground
F
or ignition circuit tests,
REFER to Section 303
-07
Engine
Ignition.

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.

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?

E
lectronic Engine Controls - Engine
Control Module (ECM) Adaptation
Gen
eral Procedures
When to car

ry out adaptations
DTCs P1000/P1111 Conditions for adaptation
Fuelling Adaptations Drive Cycle
•
NOTE: Make sure the engine is at normal operating
temperature. (75°C, 167°F) 1.
Whenever the battery is disconnected, the Engine Control
Module (ECM) adaptations are reset to a "green" ECM
condition. In this condition, certain functions of the ECM are
inhibited, and the ECM must "r elearn" these functions. To
enable the ECM to do this, the vehicle will have to perform
some maneuvres which it may, or may not, do during a normal
road test. The routine in this pr ocedure should be carried out at
Pre-Delivery Inspection, and after any emissions related
rectification work involving the disconnection of the battery.
2. When the DTCs relating to a rectified concern are cleared,
P1000 (system checks not complete since last memory clear)
will be flagged. This DTC does no t indicate a failure, just that
diagnostic drive cycles need to be performed. The vehicle's on-
board diagnostic system will confirm that all the diagnostic
drive cycles are complete by flagging P1111, (system checks
complete since last memory clear)
1. Make sure these conditions are checked and corrected, if
necessary, before carrying ou t the adaptation procedure.
MechanicalElectrical
Engi
ne oil level correct
Coo

lant level correct
F

uel level greater than
30%, less than 80%
F
uel filler cap correctly
fitted/secure, seal in good condition
Al
l rectification work
relating to DTCs completed
F
uel, ignition and cooling
systems in good order
Al
l Diagnostic Trouble
Codes (DTCs) cleared
Al
l rectification work
relating to DTCs completed
F
uses
Harnes

ses
E

lectrical connectors

1.
Either
the Jaguar approved diagnostic system (where
available), or a scan tool should be connected to measure the
Mass Air Flow rate. Most generi c scan tools should be capable
of reading this parameter.
Depending on road conditions and dealer location, it may be
difficult to achieve the road sp eeds necessary to reach the air
flow indicated. It is possible to reach these air flow figures by
inducing a load on the vehicle, (making use of hills, using a
lower gear ratio, etc) or, if no alternative is possible, by
restraining the vehicle and re aching the air flow figure
Si
te
Mass Air Flow
(gra
ms/second)
D
riving Conditions
1Up t

o 7 g/s
Idle
in
P for 2 minutes
21
0 to 14 g/s
O
pen throttle in
P for 2 minutes
31
8 to 22 g/s
O
pen throttle in
P or D with
guidance * for 2 minutes
42
5 to 30 g/s
D
rive with guidance * for 2
minutes

El
ectronic Engine Controls - Variable
Camshaft Timing (VCT) Oil Control
Solenoid
Re mo
val and Installation
Remova

l
1.
Op
en the engine compartment and fit paintwork protection
sheets.

2. Disc
onnect the batt
ery ground cable.
Re
move the battery cover.

3. Disc
onnect the VVT solenoid connector.

4. Re
move the two bolts which secure the VVT solenoid to the
timing cover.
5. Pull the VVT solenoid clear and discard the O-ring.

Contains th
e hydraulic system pump.
Contains
th
e fluid temperature sensor.
The epicyclic geartrain:
Provi des fi
ve forward gears and Reverse.
Has
h
ydraulically actuated, multi-disk clutches, to select the required gear ratios.
Feature

s clutch-to-clutch operation to permit
gear shifts for uninterrupted power flow.
The electro-hydraulic control unit:
Is lo c
ated in the lower part of
the unit, within the fluid pan.
Is controlled
by the TCM (transmissio
n control module), and the manual selector valve which is cable operated.
Re
gulates the flow of fluid to the ge
artrain clutches via three solenoid-operated valv es and the manual selector
valve.
Has fi ve pressure
regulators for controll
ing fluid pressures within the system.
Is con
nected to the TCM via a 16-way connector mounted on
the left-hand side of the transmission casing. Refer to
Connector Pins Identification, Section 307-01A.
The hydraulic system pump:
Is l o
cated at the front of the transmission casing.
Is dri
v
en from the impeller hub,
pressurising the fluid whenever the engine is running.
Supplie
s fluid under pressure to the torq
ue converter, geartrain, electro-hydr aulic control unit and the lubrication
circuit.
D r
aws fluid from the fluid pa
n below the transmission casing, through a filter.
The rear extension housing:
Is bolt
ed to the rear of the transmission casing.
Provides the rear engine / transmi

ssion mo
unting point; refer to section 303-01.
Carrie
s the transmission output shaft oil seal.
Filled-for-l
i
fe Fluid System
The
transm
ission is 'filled for life' and
does not require fluid changes, except where extreme driving conditions prevail.
Routine level checking is not required and a dipstick is not pr ovided. A level / filler plug is fitted for level checking and
replenishment, following service actions; see 303-01 General Procedures.
Transmission Torque Converter

Voltage is monitored at the regulators and solenoids for continuity and shorts. For example, when a solenoid is ON the
voltage on the TCM side should be ground , when OFF the voltage should be +12.
Shift Solenoid

The function of the three soleno id valves is to control the flow of transmissi on oil to the various transmission components.
Three solenoid valves are located wi thin the transmission assembly, and are closed when not energized.
Pressure Regulator

The function of the five pressu re regulators is to modulate the oil pressure to the various transmission components. The
regulators are pulse width modulated by the TCM, switching to ground potential. The other side of the regulators being
connected, via an internal TCM relay, to battery voltage. The regulator is closed when not energized by the TCM.
Transmission Fluid Temperature Sensor

2.2. Check on non-volatile diagnostic memory by wr iting a test pattern and then reading it back.
3. 3. Internal 'watchdog' hardware to check whether the TCM has crashed.
Transmission Control Module Supply Voltage
The TCM monitors battery and igni tion switched supply voltages.
A permanent supply is used to maintain a battery backed 'memor y'. Should this supply be cut, due to battery disconnection
perhaps, the 'adaptive shift' valu es will be lost. This will result in a small reduction in shift quality for a period until th e
adaptions are 're-learned'
The TCM will adopt 'limp home' mode as a result of the supply voltage being >16V or <7V with an engine speed >1600
rpm.
Should the ignition supply be >7V but <9V the TCM will hold the gear that it has currently selected. If after 2.5 seconds,
with the engine speed >1600 rpm, the voltage remains at this level, 'limp home' mode will be adopted. The 2.5 second
delay is built in to prevent reaction to a momentary voltage fluctuation.
Operation
CAUTION: Disconnection of the TCM and / or the vehicle batt ery will cause system adaptions to be lost; this may be
apparent by shift quality degradation. Fo llowing reconnection, a period of 'varied' driving will reinstate adaptions and thus
normal operation. Please ensure that the customer is made aware that the adaption period is variable and may occur after
handover, as the transmission re-learns the prevailing driving style.
• NOTE: Should the TCM fail, please ensure that the control housing cooling fan is operating correctly. Failure of the cooling
fan MUST be rectified before renewing the TCM and details of a fan fa ilure should accompany the returned TCM.
The TCM processes information received in both analogue and digital form, such as:
Transmission input speed Transmission output speed Throttle position Pedal demand Gear selector position Engine torque Engine speed Transmission oil temperature Mode switch
This information is then used by the TC M to control shift energy management and decide which shift program to implement
and which gear to select.
The TCM uses the various sensors and inpu ts to monitor the correct operation of the system an d is programmed to take
default action and inform the operator when a fault occurs.
Safety Functions
The safety functions are designed to safeguard against inappr opriate actions by the operator as well as against system
malfunctions. The system prevents reve rse gear from being engaged at high forward speeds and prevents manual
downshifting at excessive engine speeds; these functions are not operational in mechanical limp-home mode.
The TCM constantly monitors the transmissi on for faults. In the event of a problem the TCM will adopt a 'limp home' mode
in which only P R N D - (selector in D but only fourth gear is enabled) are available. The operator will be made aware of
certain faults by an in strument panel warning.
The electrical and diagnostic system has been designed such that system integrity is protected at all times, the safety
concept being based on th e following three points: