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 .
and/or increased performance as appropriate.
Serial Communications Interfaces
Controller Area Network (CAN)
The TCM is an integral part of the CAN system which facilita tes the interchange of real-time data between control modules
and sensors; refer to 303-14 fo r a full description of CAN.
Transmission Pressure Regulators and Shift Solenoids Circuit Diagram
ItemPart NumberDescription
1—Transmission oil temperature sensor
2—Switch
3—Shift solenoid 1 <-> 2, 4 <-> 5
4—Shift solenoid 2 <-> 3
Transmission/Transaxle Cooling - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26 -
Transmission Cooling
Description and Operation
The transmission fluid cooling system maintains fluid temperature within specified limits.
Parts List
Component Descriptions
The transmission fluid pipes:
Transfer fluid from the transmission to the cooler under the action of the hydraulic system pump. Return the cooled fluid from th e cooler to the transmission.
The transmission fluid cooler:
Is a plate type made from aluminum. Is mounted in the engi ne cooling radiator right-hand end tank.
Overheating Protection
If the engine coolant or transm ission fluid temperatures exceed their predefined limits, th e transmission control module locks
the torque converter clutch. By reducing slip, this minimises th e amount of heat transferred to the engine cooling system from
the transmission fluid.
ItemPart NumberDescription
1—Fluid pipe, oil FROM cooler
2—Fluid pipe, oil TO cooler
WARNING: NEVER USE A CFC 12 ANALYZ
ER OR NAKED FLAME TYPE.
Leak tests should be carried out with a UV spot lamp or an electronic analyzer which is dedicated to HFC 134A refrigerant.
Handling Lubricati
ng Oil
Av
oid breathing lubricant mist; it can cau
s
e irritation to the respiratory system.
Always use fresh oil from a sealed containe r and do not leave oil exposed to the atmosphere for any reason other than to fill
or empty a system. PAG oil is very hygr oscopic (absorbs water) and will rapidly become contaminated by atmospheric
moisture.
PAG oil is NOT compatible with previously used mineral based oi ls and must NEVER be mixed. Do not re-use oil when it has
been separated from refrigerant, following a re covery cycle. Dispose of used oil safely.
System Maintenance
Plug pipes an
d units immediatel
y after disconnection an d do not remove the plugs until immediately before making the
connection. Do not leave the system open to atmosphere.
The receiver drier must be renewed if the compressor has failed or if it is susp ected that debris may be present in the
system.
It is not always necessary to renew th e receiver drier if the correct procedur es have been followed. However, if a
component or part of the system is left dismantled for more than five minutes, it may be advisable to renew the receiver
drier. This guidance is based on UK average humidity levels; lo cations with lower humidity levels will be less critical to
moisture contamination. It must be stressed however th at there is not a safe period for work to be carried out in.
Do not use any replacement parts su pplied without transit plugs and seals - return them to the supplier.
Diagnostic equipment for pres sure, mass and volume should be calibrated regularly and certified by a third party
organization.
Use extreme care when handling and securi ng aluminum fittings; always use a backing spanner and take special care when
handling the evaporator.
Use only the correct or re commended tools for the job and apply the manufacturer's torque specifications.
Graph - High S
ide Pressure against Ambient Temperature
Probable
causes of faults may be found by comparing actual
system pressures, registered on your manifold gauge set or
recovery / recharge / recycle station, and the relevant pressure to temperature relationship graph. The following chart
shows the interpretation that ma y be made by this difference.
• NOTE: The A/CCM will disengage the compressor clutch should the evaporator temperature fall to 0°C.
• NOTE: Graphs are typical for HFC 134A
The 'Normal' condition is that which is relevant to the prevailing evaporator temperature.
System Pressure Fault Classification
• NOTE
: If erratic or unusual gauge move
ments occur, check the equipment against a known (calibrated) manifold gauge
set.
This table should be used in conjunction with the graphical representations of 'High side' pressure / ambient temperature
and 'Low side' pressure / evaporator temperature.
Leak
Test
F
a
ults associated with low re
frigerant charge weight and low pressure ma y be caused by leakage. Leaks traced to
mechanical connections may be caused by to rque relaxation or joint face contamination. Evidence of oil around such areas
is an indicator of leakage.
Models that have fluorescent tracer dye incorporated into the refrigeration system can be checke d for non-apparent leaks by
scanning with a high intensity ultraviolet lamp. The location of leaks can be pinpointed by the bright yellow glow of the
tracer dye.
CAUTION: Observe ALL safety precautions associated with ultraviolet equipment.
Should a leak be traced to a joint, check that the fixing is secured to the correct tightening torque before taking any other
action.
When examining the system for leaks, chec k the compressor shaft seal and evaporator.
Charge Re
covery (system depressurization)
The process of
charge r
ecovery will depe
nd on the basic characteristics of your chosen recovery / recycle / recharge
equipment, therefore, follow the manu facturer's instructions carefully.
Remember that compressor oil may be drawn out during this process, take note of the quantity recovered so that it may be
Lo
w side
gauge reading
High s i
de
gauge reading
Fau l
t
Cause
No
r
mal
No
r
mal
Di
sc
harge air initially cool then
warms up
Mois
ture in system
N
ormal
to low
No
r
mal
As aboveAs above
LowLowD
i
scharge air slightly cool
Ref
r
igerant charge low
LowLowDi
scharge air warm
Refr
igerant charge very low
LowLowDi
scharge air slightly cool or frost
build up at expansion valve
Expansion valve st
uck closed
LowLowDi
scharge air slightly cool,
sweating or frost after point of restriction
Restri
ction in High side of system
HighLowCompressor noisyDe
fe
ctive compressor reed valve
HighHighD
i
scharge air warm and high side
pipes hot
Refri
gerant charge high or inefficient condenser
cooling due to air flow blockage or engine cooling fans
not working
HighHighD i
scharge air warm / Sweating or
frost at evaporator
Expans ion valve st
uck open
Symp
tom #5
Sy
m
ptom #5
Low r
e
frigerant charge
*
Check f or 'hissi
ng' at expansion
valve; may be witnessed by low
HIGH side pressure. Recover / recharge
*
Moi
s
ture or air in the system
*
Chec k syst
em pressures
*
Heat er ci
rcuit air-lock
*
R e
fer section 303-03 for fill / bleed procedure
*
Suct ion
pipe touching bank 1 (A)
cylinder head (rubber isolator
missing)
*
Check the pi
pe cluster for correct fitti
ng
*
• NOTE: Electrical faults may be more rapidly traced using PDU
Sym
ptom
Possib
l
e Sources
Acti
o
n
Insuffi
ci
ent
heating
Coo l
ant flow valve stuck 'closed'
Coolant flow valve stuck 'open' allowing recirculation of
coolant at engine idle
*
*
Re
new v
alve
*
Motorized in-car aspirator sei zed
*R e
new aspirator
*
Coo l
air bypass damper stuck open
*
Re new,
check fault code #43
*
B l
ocked air inlet / pollen filter
*
Chec k / cl
ean / renew
*
B l
ower speed low
*
Check performance range
*
Low cool ant
level
*
Adjust as req u
ired (verify and correct
reason for loss)
*
Engine
t
hermostat faulty
*
Check engine r u
nning temperature
*
Heater water pump seized
*Chec k op
eration
*
Heater ma trix
blocked
*
Re new m
atrix
*
Heater circui t
air-lock
*
R e
fer section 303-03 for fill / bleed
procedure
*
Sym
p
tom #4
Sym
ptom #4
Sy
m
ptom
Possib
l
e Sources
Acti
o
n
No
i
sy
system
Loose or damaged compressor drive
belt
*Adjust or r
e
new
*
Loose compressor mountings
*Check f o
r damage, tighten to specification if OK
*
Compressor oil level l
ow
*
Look for evidence of l
eakag
e and rectify as required
*
Compressor internal dama ge
*Check f o
r debris, renew compressor and receiver drier
*
B l
ower motor noise
*
Re new m
otor (assuming no fan interference)
*
Excessive refrige rant charge
*Check f o
r vibration or 'thumping'
in high pressure line; may be
witnessed by high pressure on both HIGH and LOW sides.
Recover / recharge
*
Climate Co
ntrol System - General In
formation - Air Conditioning (A/C)
System Check - Re tail Procedure
Gen
eral Procedures
E
vacuating the Manifold Gauge Set
Connecting the Manifold Gauge Set
C
AUTION: Only use hoses with connectors wh
ich are dedicated to HFC 134A charge ports.
Stabilizing the System
1.
At
tach the center (service) hose to a vacuum pump and start
the pump. Open fully both high and low valves and allow the
vacuum to remove air and mois ture from the manifold set for
at least five minutes.
CAUTION: It is imperative th at the vacuum pump is not
subjected to a positi ve pressure of any degree. Therefore the
pump must be fitted wi th an isolation valve at the center (service
hose) connection and this valve mu st be closed before the pump
is switched off. This operation replaces the 'purge' procedure used
on previous systems. Observe the manufacturer's
recommendation with regard to vacuum pump oil changes.
Turn the vacuum pump off and isol ate it from the center service
hose but do not open the hose to atmosphere.
1. Att
achment of the hose quick release connectors to the high
and low side system ports is stra ightforward, provided that the
high and low valves are closed and the system is NOT
operational.
WARNING: UNDER NO CIRCUMSTANCES SHOULD THE
CONNECTIONS BE MADE WITH THE SYSTEM IN OPERATION OR
THE VALVES OPEN. SHOULD THE VALVES BE OPEN AND A
VACUUM PUMP OR REFRIGERANT CONTAINER ATTACHED, AN
EXPLOSION COULD OCCUR AS A RESULT OF HIGH PRESSURE
REFRIGERANT BEING FORCED BACK INTO THE VACUUM PUMP OR
CONTAINER.
Assessment of system operating efficiency and fault
classification may be achieved by using the facilities on your
Recovery / Recharging / Recycling station, follow the
manufacturer's instructions implicitly and observe all safety
considerations.
1. Accurate test gauge data wi
ll on
ly be attained if the system
temperatures and pressures are stabilized.
E
nsure that equipment and hoses cannot come into
contact with engine moving parts or sources of heat.
It is recommended th at a free standing air
mover is placed
in front of the vehicle to provide air flow through the
condenser / cooling system.
St
art the engine, allow it to attain normal working
temperature and set at fast idle (typically 1200 to 1500
rpm).
Select full
air condit
ioning performance.
With
all temperatures and pres
sures stable, or displaying
symptoms of faults; begin relevant test procedures.
System Self-test
Control Panel Fault Code Listing • NOTE: Reference fault code #23*: In ambient temperatures below 0° C, this code may be logged because the low
ambient causes a tempor ary low gas pressure.
• NOTE: Where the ambient temperature rises above 40° C, with the engine close to overheating, electrical feed to the
compressor clutch may be cut and code #23 registered.
SymptomPossible SourcesAction
0 Normal operation no
fault codes presentNone
*Wait 30 seconds for system
self-check.
*
11 Motorized in-car
aspirator malfunctionHarness / connector fault
Sensor open / short circuit
*
*Panel fault codes are not
stored for motorized in-car
aspirator motor failure.
*
12 Ambient
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*After rectification, disconnect
the vehicle battery for 10
seconds to reset the system.
*
13 Evaporator
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*Refer to PDU
*
14 Water temperature
input malfunctionInstrument cl uster output
*Refer to PDU
*
15 Heater matrix
temperature sensor
malfunctionHarness / connector fault
Sensor open / short circuit
*
*Refer to PDU
*
21 Solar sensorSensor open /short circuit
*Refer to PDU
*
22 Compressor lock
signal faultLow refrigerant charge, low compressor oil level, loose drive
belt Harness / connector fault
*
*Adjust items as required
*
23 Refrigerant pressure
switch malfunctionHarness / connector fault
Switch open / short circuit
*
*Refer to PDU
*
23 Refrigerant pressure
low refrigerant charge * Leak from damaged pipe or joint
*Rectify as required and
recharge system
*
24 Face vent demand
potentiometer faultPotentiometer open / short circuit
Harness / connector fault
*
*Refer to PDU
*
31 LH fresh / recirc.
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
32 RH fresh / recirc.
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
33 Cool air by-pass
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
34 Defrost vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
35 Centre vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
36 Foot vent
potentiometer faultHarness / connector fault
In certain circumstances the servo motor may over-travel
and cause further logged faults. This may be cured, following
fault rectification, by cycling the ignition ON-OFF-ON 3 times
*
*Refer to PDU
*
41 LH fresh / recirc.
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*
42 RH fresh / recirc.
motor faultHarness / connector fault
Servo motor seized or sticking
Flap seized or sticking
*
*
*Refer to PDU
*