traction control JAGUAR X308 1998 2.G User Guide

Speed an
d load
Coo
l
ant temperature
Ti
me el
apsed from start up
Cl
osed l
oop fuelling
Determination of the vapour concentration is made by stepped opening of the EVAP valve and subsequent monitoring of the
fuelling correction. This function is performed prior to purging, so that at the onse t of purging the EVAP valve can be set to
the optimum position. Should the ECM be unable to determine the concentration before purging, a default value is
employed, which is then modified whilst purging is in progress.
When the purging process is operational th e ECM modifies the basic fuelling calculation to maintain the correct air / fuel
ratio.
Purging is inhibited during fuel cut-off and stability / traction control intervention.
Coolant Temperature Sen
sor
Th
e
sensor outputs a voltage to the ECM which decreases as temperature increases.
Cooling Fans


In response to engi
ne coolant temperat
u
re and climate control system demand, the ECM will energize the cooling fans.
Climate Control Compressor
The E
C
M will allow the compressor clutch to be engaged if th
e engine temperature and load demand are normal. Should the
driver require maximum engine powe r or the coolant temperature be high, the request will be denied.
Cranking Signal

The ECM reacts to a signal fr
om th
e Body Processor Module (BPM) when the starter motor relay is energi
zed. This signal is
used to trigger starting, fu el and ignition strategies.
Engine Speed and Cranksh
aft Position
Engine
speed and cran
k position are moni
tored by a sensor which is mounted on the cylinder block (flywheel housing)
behind the crankshaft drive plat e. It indicates rotational speed to the ECM in the form of 12 pulses per crank revolution.
Engine speed is used for synchronization of fuel an d ignition systems, as well as other functions.
Camshaft Position
The ca
mshaft position sensor is mounted at
the rear of Bank 2 cylinder head on the inlet side and provides one signal every
720 degrees of crankshaft rotation. The signal, in conjunction with the signal from the crankshaft position sensor, indicates
to the ECM that the piston of cylinder 1A is approaching TDC on the compression stroke.
Variable Valve
Timing (Where Fitted)
By energi
si
ng a solenoid to allow the pass
age of pressurized oil on each of the inle t camshaft drives, the ECM can vary by a
single stepped amount, the relati ve timing of the inlet valves.
Ign
ition
Ignit
i
on spark is produced by
individual on-plug coil units.
There are two ignition amplifiers; module #1 drives coils 1A, 2B, 3B and 4A, whilst module #2 drives coils 1B, 2A, 3A and
4B. The ECM controls the amplifiers.

2.2. Cruise
3. 3. Mechanica l
guard
4. 4. Fixed idle
5. 5. Redundancy
6. 6. Full authority
7. 7. Engine shut-down
Normal mode occurs when the EC M uses the mechanical and monitoring arrangem ent of the throttle valve to control throttle
opening. The ECM does not permit driver demand to be exceeded but it can be restricted to allow for such features as
stability / traction control, or engine power limitation.
The ECM determines engine idle speed by controlling the throttle valve motor to vary the blade angle between the non-
adjustable preset limits of the mechanic al guard and the throttle valve motor.
Cruise mode is engaged as a result of the ECM calculating and controlling the required throttle valve opening via the
vacuum system. When the driver releases the throttle pedal, the input shaft disengages from the mechanical guard or the
vacuum actuator pulls the guard away from th e throttle valve. The throttle pedal will feel light should it be pushed again to
accelerate (pressing the pedal further will re-engage the input shaft with the mechanical guard and restore normal feel).
The ECM utilizes sensors to monitor the relative positions of the mechanical guard and throttle valve and adjusts them to
maintain the set cruise speed.
Mechanical guard mode permits full mechanical operation of the throttle if the ECM detects that a problem has been
encountered with the throttle valve position sensor, dc motor, associated harnesses / connecto rs or the ECM.
Fixed idle mode occurs when any two of the three sensors (two input shaft sensors and the mechanical guard sensor) fail.
The ECM will assume values which represent a blade angl e of approximately 2,5° and 1200 rpm (unloaded) maximum
engine speed.
Redundancy mode occurs when any one of the three sensors (two input shaft sensors and the mechanical guard sensor)
fails. The operational pair will be deemed to be safe to co ntinue without intervention, but cruise will be inhibited.
Full authority mode is invoked when a mech anical guard failure occurs which indicates that the guard is stuck fully open.
The red warning lamp will be lit and road speed will be li mited to 120 kph.
Engine shut-down mode will occur followin g multiple failures, such as mechanical guard mode following full authority mode
(or vice versa) or the throttle blade sticks.
Intake Elbow

The intake elbow directs the metered airflow from the electronic throttle to the intake manifold. Stub pipes on both sides of

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.

Controller Area Network (CAN)
The TCM is an integral part of the CAN system which facilitates the interchange of real-time data between control modules
and sensors. Please see section 303- 14 for a full description of CAN.
OBDII Interface
Data concerning OBDII related transmission failures is stored in the ECM for access via the J1962 socket.
System Functions
Range Selection
The selector lever is connected to the transmission via a bowden cable, which operates the transmission selector shaft
between all positions except Drive to 4 .
The TCM detects the gear selected by means of a rotary position switch fitted to the transmission selector shaft. A separate
Drive to 4 switch is located within the 'J' gate' assembly.
Movement of the selector lever between Park, Reverse, Neutral and Drive manually directs th e flow of transmission oil; the
TCM having control of the forward gears selected while the lever is in the Drive position.
Shift Point Selection
The gearshift points are selected, by the TCM, as a function of the output speed, engine load, selector position and shift
program selected. The operator has control over the shift points via the selector lever, throttle pedal movement, kickdown
function and mode switch.
'J' Gate Layout

Mode Switch
This switch allows the driver to select one of two base shift maps; Normal and Sport modes, the switch being illuminated
when Sport is selected.
Special Shift Programs
These specific condition shift maps are available to enhance the operation of the vehicle under specific driving conditions.
and are listed below in order of priority / title and operating condition.
1. 1. Traction: When traction intervention is active
2. 2. Hot mode: Extreme engine / transmission temperatures

3.3. Gradient: Under specific speeds and loads
4. 4. Cruise: During cruise control
5. 5. Manual: Shift map when the LH side of the 'J gate' is used
Three specific condition shift maps have a higher priority than the two base shift maps and will intervene when appropriate
conditions prevail for traction, gradient or cruise.
When traction control (engine or brake system derived) is operational the TCM will implement the traction map to maximise
control of wheel slip.
The gradient maps are intended to enhance vehicle drivability when towing or climbing a gradient. The TCM will implement
the maps when increased driving resistan ce is detected and enhanced drivability, cooling and increa sed performance is
appropriate.
The cruise map is intended to minimize unwanted gearshifts and 'hunting' and is activated when cruising near to the set
speed, or resuming.
Connector Pins Identification
Connector Pin Identity Chart for EM007

Pin NumberCircuit Function
001Pressure regulator 2
002Mode switch status
003Not used
004Pressure regulator #4
005Pressure regulator #1
006Power ground
007Not used
008Rotary switch L2
009Rotary switch L4
010 to 011Not used
012Mode switch Pin B (Sport)
013D to 4 switch
014Input speed sensor (-)
015Output speed sensor (screen)
016Output speed sensor (+)
017Not used
018Kickdown switch (where used)
019 to 020Not used
021Analogue ground
022Fluid temperature sensor
023Input speed sensor (screen)
024 to 025Not used
026B+
027Not used
028Digital ground
029Pressure regulator #3

CAN Input Signals
Traction status ABS malfunction ABS status Engine torque status Throttle position Accelerator pedal position Engine torque reduction confirmation Engine speed Engine coolant temperature Cruise status OBDII fault code clear request Throttle malfunction warning RED or AMBER All road wheel speeds Token for network status ECM Token for network status INST Token for network status ABS Diagnostic data in from external device (PDU)
Output Signals
Solenoid valve 1 <-> 2 and 4 <-> 5 shift Solenoid valve 2 <-> 3 shift Solenoid valve 3 <-> 4 shift Solenoid valve converter lock-up clutch Control valve - modulating pressure Control valve - shift pressure
CAN Output Signals
Engine torque reduction request MIL status (whether present DTC should operate MIL) Transmission input speed Transmission output speed Converter slip Kickdown status Gear position (actual) Gear position (selected) Gear selection fault Converter lock-up status Current selected shift map Transmission oil temperature Transmission malfunction Pecus flag (state of current TCM program) Target for next gear position Gear shift torque transfer progress at shift MIL status (response to activate the MIL relevant to a DTC) OBDII fault code clear acknowledgement Transmission DTCs (P codes) Token for network status TCM Diagnostic data out to external device (PDU)
Emergency Running (elect ronic limp-home mode)
The TCM constantly monitors the transmissi on for faults. In the event of a problem the TCM will adopt the limp-home mode, in which the gear currently held remains engaged, until P is selected. The modulati ng and shift pressures will increase to
maximum and converter lock-up will be inhibited.
Following the selection of P , the only ratios available will be 2 (irrespective of forward ratio manual selection) and R .
With the vehicle at rest, the procedure to manually select is as follows:
1. 1. Select P .

Range Selection
The 'J' gate selector lever is connected to the transmission via a cable which operates the transmission selector shaft
between positions P R N D only. The shift lever disconnects from the cable when the lever is moved across the gate from D
to 4 .
Movement of the lever between P R N D manu ally controls the flow of transmission fluid, the TCM having control of the
forward gear selected in D .
Movement of the lever to 4 , 3 and 2 positions does not manu ally modify the fluid flow, the TCM detects these positions
using the DLS and controls the ratios electronically by energizing solenoids.
Shift Point Control
The gearshift points are controlled by the TCM, as a function of the output speed, engine load, engine speed, selector
position and shift program selected. The operator has control over the shift points via the shift lever, throttle pedal
movement, kickdown function and mode switch.
Mode Switch
This switch allows operator selection of two base shift modes; Normal and Sport; th e switch being illuminated when Sport is
selected. This function alters the values in the TCM shift point calculations.
Shift Programs
Upon encountering the following conditions, the TCM will auto matically modify the Normal or Sports shift map to enhance
the operation of the vehicle:
1. 1. Traction: When traction intervention is active.
2. 2. Hot mode: Extreme engine/transmission temperatures.
3. 3. Gradient: Under specific speeds and loads.
4. 4. Manual: Driver initiated override of the normal shif t map when the LH side of the 'J gate' is used.
Traction
When traction or stability control (engine or brake system de rived) is operational the TCM will implement the traction map
to maximize control of wheel slip.
Gradient
The gradient function is intended to enhance vehicle drivea bility when climbing a gradient or towing. The TCM will
implement the function when increased driving resistance is de tected, and provides enhanced driveability, additional cooling

System Self-test
Control Panel Interrogation Procedure
The control panel has a self-diagnosis feature, and is capable of displaying and clearing stored fault codes.
Climate control is an integrated system, therefore it is recommended that the PDU is used for fault diagnosis. The fault
codes displayed with the control panel self -diagnosis feature are not as comprehensive as those of the PDU. The PDU will
display the relevant fault code, fault co de description and information of the system peripherals at the time the fault
occurred.
Fault Code Extraction and Deletion Procedure
Error information is stored in the A/CCM up to a maximum of 5 faults. Should a sensor fault occur there will be an audible
beep and the message Er will be displayed on the control panel display for 5 seco nds after ignition on. Please note that this
will happen only once in any ignition switch cycle. The error source may be accessed by the following procedure
This procedure must be completed through one complete cycle, 1 through 6
• NOTE: * Actuator codes do NOT equate to system fault codes.
• NOTE: Only codes 11, 15 and 21 (see Fault Code List ing) will cause audible beep and 'Er' display.
• NOTE: If '0' is displayed, there are no stored faul t codes, wait 30 seconds to allow system self-test.
The control panel display will flash repeatedly indicating a list of two digit numbers (see table for code analysis). Should a code be displayed accompanied by an audible beep, the fault is current and therefore still present within
the system. A code displayed without an accompanying 'bee p' indicates a fault had previously occurred but is not
present within the system.
• NOTE: It is advisable to check all areas indicated with cleared fault codes. Such faults may re-occur if intermittent
problems are present in the system.
To delete stored and cleared fault codes press 'R' and 'FAC E' buttons simultaneously. After investigating and correcting all stored faults, press the 'Push Off' button to restore normal operation with
default panel settings, ie AUTO at 24°C.
Pin #DescriptionCable color
1O/P clockSlate
2O/P startSlate / Red
3I/P dataSlate / Yellow
4O/P dataSlate / Green
5O/P ignition +veWhite / Red
6O/P auxiliary +veWhite / Blue
7O/P groundBlack
8DimmerRed
9Dimmer overrideRed / Green
10Not usedn/a
11Not usedn/a
12Not usedn/a
StepResult
#1 Simultaneously hold AU TO and RECIRC - Switch
ignition to ONDisplay element check
#2 Press AUTODisplay of stored fault (NUMERIC) code. If ZERO appears, there are
no stored codes
#3 Press FACEScroll through stored faults (maximum of 5)
#4 Simultaneously press FACE and RClear stored fault codes (may need to be repeated for each fault)
#5 Press RECIRC (Press FAN to skip actuator check)Initiate actuator check (Actuator codes 20 through 27 * )
#6 Press FANExit error check mode

Heelboard Fuse Box - Left hand side

Trunk Fuse Box
105Radio telephone, rear courtesy lamp/map light.
1120Air conditioning right-hand blower relay.
125In-car entertainment.
1325Right-hand rear door control module.
1425Cigar lighters.
1525Right-hand door control module.
16-Not used.
1715Sunroof.
1825Right-hand and left-hand seat heaters.
Fuse NoRating
(amps)Circuit
120Right-hand seat control module.
25Rear window switchpack, driver door key ba rrel, driver door switchpack and memory.
35Dimmer module.
45Diagnostic connector.
515Body processor module.
65Centre console switchpack, reader exciter ECM
715Body processor module (battery supply for solenoids, lamps and motors).
85Steering column adjust switch, driver seat switchpack.
910Radio/cassette head unit.
105Airbag/SRS
1120Air conditioning left-hand blower motor.
1210Door mirror heaters relay, air conditioning, blow er motor relays, power steering control module.
1325Left-hand rear window
1410Cruise control switch, instrument cluster, catalytic converter over temperature warning.
1525Left-hand door control module.
165Electrochromic interior mirror (where fitted), centre console switchpack, gear selector, traction control
switch illumination, J-gate mode switch illumination, pins A9 and D8 trunk fusebox.
1710Accessory supply.
185Instrument cluster.
Fuse Rating

Parts List
The Center Console Switch Module comprises the integral switches identified in the illustration above. All switches with the
exception of the Traction Control Switch are connected to BPM inputs. The Traction Control Switch is connected to an ABS
unit input.


ItemPart NumberDescription
1—Central locking switch
2—Valet switch
3—Left hand seat heater switch (where fitted)
4—Right hand seat heater switch (where fitted)
5—Traction control switch (where fitted)
6—Hazard warning switch