
Automatic Transmission (AJ16) 
8.1.4 FA U1 T DIAGNOSIS 
Transmission  Control System Electrical - P 0702 (Fig. 1) 
This fault  code  is associated  with the internal relay of the  Transmission Control Module, (TCM). This relay  provides a 
means  of isolating the  electro-mechanical, controlling, solenoids from the supply,  allowing the transmission  to revert 
to a mechanical  default condition. 
The  relay and  associated  circuitry is tested once during initialization  and whenever 
a hardware reset occurs. When  the 
ignition  is first  switched on the  TCM carries  out an initialization routine. During  this routine the  processor drives the 
relay 
ON then  tests  for the  supply voltage  on the output via a feedback  path. If the supply voltage  is not  seen  within 
a  specific  time then 
a fault  is flagged  and the TCM  will run in default mode  and this fault  code  will be stored. 
A set  time  after the relay is turned  on, it is turned off and  the processor  then tests  for the supply  again. If it is still  present, 
then the  TCM will run in default mode and this fault  code will be stored. 
U: The  ignition  supply voltage  must be greater  than 8V for a fault code  to be  stored. If this  fault is permanently 
flagged,  the TCM  should  be replaced  taking care to obtain the correctly programmed variant. 
Possible causes: 
Faulty  TCM internal  relay. 
Effects: 
. MIL illuminated. 
. Transmission  warning lamp illuminated. 
. Maximum fluid pressure  applied. 
Limp home mode  applied. 
. RenewTCM. 
Remedy: 
Fig. 1 
X300 EDM 5 Issue 1 August 1994  

w Automatic Transmission (AJ16) 
SOL ENOlD VALVES 
The following  tests are performed continuously  by a background  task. If a fault  is detected, it is filtered for a set period. 
When  filtering  ends a fault  code is stored in the TCM  and action  is taken  to ensure  the integrity  of the  system. 
During  limp home  mode the internal  relay is turned 
off to  remove  the supply  to the  solenoids  and the gearbox with default  to fourth  gear (if aforward  gear is alreadyselected) and third  gear (if P.R.N.). Selecting  N and  then D will engage 
3rd  gear  only. 
Each  test checks  that the feedback  from the output  stage module  is consistent 
with the  driven  state of the  solenoid 
output,  detects short circuit to ground,  short circuit to battery voltage and open  circuit. 
TORQUE CONVERTER  CLUTCH SYSTEM - P 0743 
PRESSURE  CONTROL  SOLENOID  ELECTRICAL 
- P 0748 
SHIFTSOLENOID A ELECTRICAL - P 0753 
SHIH SOLENOID B ELECTRICAL - P 0758 
TCM  TRANSMISSION 
ccoo7/042 G B003/L 
CC007l005 GBOOYH 
ccoo7/024 GB003lK 
CC007/006 GB003/B 
CC007/0 19 G B003/M 
TORQUE CONVERTER  CLUTCH 
SHIFT  SOLENOID 
A 
SHIFT  SOLENOID B 
PRESSURE  CONTROL SOLENOID 
SOLENOID  SUPPLY 
Possible Causes: 
. Faulty valve. 
Faulty  harness wiring /connectors. 
Effects: 
MIL illuminated. 
. Transmission  warning lamp  illuminated. 
Maximum fluid  pressure applied. 
Limp home mode  applied. 
Remedy: 
Renew valve. 
. Repair or renew harness I connector. 
Issue 1 August 1994 14 X300 EDM  

Climate Control Systems 
.-) 
14.1 SYSTEM DESCRIPTION 
The Air Conditioning electronic Control  Module (A/ CCM)  located  on the  right-hand  side of the  A / C unit, controls  the 0 functions  of the  system. 
These  functions  include: 
0 In-car temperature  control 
0 In-car humidity control  (Air conditioning  vehicles only) 
0 Air flow / volume  and distribution 
The  temperature  of the  passenger  compartment  is continuously compared  with the temperature  selected on the  con
- trol  panel  LCD. A digital  microprocessor  within the A/ CCM  receives  the data signals.  Comparison of these  signals 
and  those  from system temperature  sensors and feedback devices  results in the appropriate  output voltage  changes 
needed  to vary  the blend  of air  flow  into the passenger  compartment. 
The  climate control  system peripherals communicate  with the A/ CCM  via three  main device categories  comprising 
of  manual  inputs, automatic  outputs and inputs,  as shown 
in Fig. 1. 
Air  Temperature Control I 
9 Recirculation  switch 
. Air con on/off switch 
System on/off switch 
. Auto. / Man. select 
Set temperature 
. Air flow  outlet mode  set 
Heated  front screen  switch 
. Heated  rear  screen & 
heated  mirror switch 
. External  temp.  display 
switch 
. FahrenheiVCentigrade switches 
4 
. Solar sensor 
. Motorized  in-car aspirator 
. Ambient  temp.  sensor 
. Evaporator  temp. sensor 
Heater  matrix temp. sensor 
. Compressor lock sensor 
. Face differential  temp. control 
. Refrigerant  pressure  switch 
. Engine speed signal 
Engine coolant temperature 
Vehicle  speed signal 
. Circulation  pump 
. Water valve 
. Power  transistor (fan  speed 
Servo motor  potentiometers: 
signal 
control) 
LH  air  inlet  flap 
RH air inlet  flap 
Centre  vent flap 
Foot  flap 
Defrost  flap 
Air  by
-pass  flap 
Air Inlet Control 
9 LH air inlet 
. RH air inlet 
CONTROL PANEL 
1 
A / CCM 
I I 
I . External  temp. display I 
. Coolant  recirculation valve 
. Coolant recirculation pump 
LH blower  motor & power transistor 
. RH blower motor & power transistor 
. LH high speed relay 
Air Distribution Control 
Servo  motor  for: 
9 Centre  vent flap 
Foot  flap 
Defrost  flap 
Fig. 1 Schematic  view A / CCM  Inputs & Outputs 
X300 EDM 1 Issue 1 August 1994  

Climate Control Systems 
28- 
I llSA I 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
IO. 
11. 12. 
13. 
14. 
15. 
21J 20 
Instrument  pack 
Fascia  switch  pack 
Defrost servo. 
Air distribution box  Solar  sensor 
Control panel 
Centre  console 
LH  blower  motor 
Water  valve 
Circulation pump 
Coolant  temperature  sensor 
LH  front  fuse
-box 
Circulation pump relay 
Ambient  temperature  sensor 
A 
/ C compressor 
17 
16. 
17. 
18. 
19. 
20. 
21. 
22. 
23. 
24. 
25. 
26. 
27.  28. 
29. 
16 1's J86 1767 
Compressor  clutch relay 
Trinary pressure  switch 
Radiator  fan pressure  switch 
Control module 
RH blower  motor 
Engine  control  module 
Motorized 
in-car aspirator 
A 
/ C isolate  relay 
RH blower motor  high speed  relay RH blower motor relay 
LH  blower motor high  speed relay 
LH blower motor relay 
- 
- 
Fig. 1 Component Location  Diagram 
Issue 1 August 1994 2 X300 EDM  

Climate Control Systems 
14.2.3 Solar Sensor  (Fig. 1) 
The solar  sensor  is mounted  on top of the  facia, between  the 
facia  defrost  grilles. 
The  sensor  isconstructed around 
a photo-diode to measure 
direct  sunlight.  The sensor  provides an output  response  sig- 
nal totheA1CCM;thisensuresthe in-cartemperaturestabil- ity whilst  reducing outlet temperature  to compensate  for 
solar  load heating.  The solar  sensor  is fitted  to aircondition- ing vehicles  only. 
14.2.4  Engine Speed Signal 
The A 1 CCM  receives  an engine  speed signal from the En- gine Control Module (ECM). 
This signal facilitates  compressor lock sensing (12 cyl. ve- hicles only). 
This  signal  also  aids  the A 
1 CCM  inhibition  of the  heated 
screen relays.  At engine  speeds  lower than 800 RPM the A I CCM  assumes  poor idle or engine  not running  and will not 
permit the  selection of the  heated  screens. 
14.2.5  Ambient Temperature  Sensor (Fig. 2) 
The ambient  temperature  sensor is located  within the LH 
brake cooling  duct. 
The sensor detects  exterior airtemperature  and provides the 
A 
I CCM  with a signal  to allow compensation  for ambient 
conditions. 
The  A 
1 CCM  is then  capable  of informing  the control  panel of the  ambient air temperature  in both  Centigrade  and 
Fahrenheit,  and  updates  the information  every four 
seconds. 
The  sensor  is damped  and 
so does not detect  temperature 
fluctuations  as quickly  as other temperature  sensors. This 
facility  prevents  temporary temperature fluctuations  affec
- ting overall temperature control. 
14.2.6  Vehicle Speed Signal 
The A 1 CCM  receives a road speed  signal from the instru- ment  pack, derived  from the ABS 1 TC CM. 
This signal  is required  to control the blower fan  speed to mi
- nimise the  effects of ram air, i.e. blower fan  speed changes 
in  proportion  to vehicle  road speed. 
The  signal  also determines  the frequency 
at which the ambi- ent air  temperature is  updated. The road  speed compensa- 
tion  for blower  control  is inhibited  when  the  selected 
temperature  is 'LO  (maximum cooling) and 'HI' (maximum 
heating)  and defrost mode. 
14.2.7  Evaporator  Temperature  Sensor 
Located next to the  evaporator  fins, the sensor  detects  the air temperature leaving the  evaporator, and sends  this sig- nal to the  A 1 CCM. 
When  the temperature  approaches 
OOC, the A 1 CCM  disen- 
gages  the compressor  to prevent freezing  conditions. When 
thetemperature  rises above3OC.theAlCCM re-engagesthe 
compressor. 
J82-L06 Fig. 1 
Fig. 2 
0 
0 
Issue 1 August 1994 4 X300 EDM  

Climate Control Systems 
14.2.8  Heater  Matrix Temperature  Sensor 
This sensor  is positioned inside the  air conditioning  unit just 
downstream of the  heater matrix.  The sensor  monitors the 
post
-heater  air temperature, before  the air is distributed  to 
the  passenger  compartment.  In conjunction  with the A / CCM  this sensor  provides the  input to maintain a constant 
outlet  temperature. 
14.2.9  Coolant Temperature  Signal 
This input  is required  to provide blower  inhibit control,  to 
avoid cold 
air being delivered  in heating mode when the  en- gine  coolant temperature is  below 3OOC. The input  also 
monitors  the temperature of  the  coolant  delivered to the 
heater  matrix to assist  outlet temperature control. 
14.2. IO Compressor ON Signal 
This signal line monitors the  compressor relay to inform  the 
A/  CCM  of the  compressor status and to facilitate  lock detec- 
tion  and error  sensing. 
14.2.11 Motorized In-car Aspirator  (Fig. 1) 
The Motorized In-car Aspirator  (MIA) detects  the air tem- perature  within the passenger  compartment.  A small  motor 
driven fan  (blown aspirator) draws  air across  the thermistor, 
which  changes  its electrical  resistances  in response  to 
changes  in air temperature,  converting 
a temperature rating 
into  an electrical  signal. 
The  MIA  is  located  on  the back of  the  driver's  side  knee 
bolster. 
14.2.12  Compressor  Lock Signal - 12 cy/. vehicles  only 
This signal provides  the A / CCM with compressor  rotation 
speed.  This is then compared  with engine  rotation  speed. 
If the ratio of the  compressor speed against  engine speed 
drops belowthe A/CCM limits, indicating compressor/ belt 
slippage,  the compressor  clutch is disengaged. 
When  compressor  clutch disengaging  commences the A/C 
LED on the  control  panel will flash  once per second. 
14.2.13  Refrigerant  Pressure Switch (A/C Vehicles only) 
The refrigerant  pressure switch (Fig. 2) is located under  the 
hood  on the  liquid  line. 
The  switch  contacts  open  when  abnormal  pressures are 
sensed.  This action  inhibits  the compressor  clutch drive. 
14.2.14  Water  Valve 
The water  valve is used  in conjunction  with the water  pump 
to  regulate  the output  air temperature.  The water  valve is off when the  ignition is on,  engine  not running. 
14.2.15  Water  Pump 
The water  pump  is energized  in all  engine  running  modes 
except  for under  cold coolant condition at blower  inhibit and 
in  panel 
off mode.  The water  pump  is off when the  ignition 
is  on,  engine  not running. 
If 
J82-488 
KI Fia. 1 I 
Fia. 2 
X300 EDM 5 Issue 1 August 1994  

Climate Control Systems 
0 
0 
14.3 CLIMATE CONTROL  MODULE CONNECTIONS 
Fig. 1 Control  Module  Connector  Pins 
J80-098 
IGN, activated  high 
0 Io(22-way) Input  Diagnostic L-Line 
11 (22-way) Input  Water pump motor  current  Current detection  resistance 7mQ 
12 (22-way)  Output  Ignition (+VE) to control  panel 
13  (22
-way)  System Ground 
14  (22
-way)  Output  Ground to control  panel 
15  (22
-way)  Output  Air con isolation  relay  Activated  when IGN ON and  for 30 sec- 
16 (22-way)  Input  Vehicle speed input 
17  (22
-way)  Input  Pressure switch  Ground for normal  pressure. 
IGN+ for abnormal pressure 
18  (22
-way)  Output  Aspirator  motor (In+ar sensor) 0.05A at 12V, activated high during  ON 
mode  only 
19  (22
-way)  Input  Sensor ground 
20  (22
-way) 
21  (22
-way)  Output  Diagnostic K-Line 
onds after IGN  OFF 
Logic  ground  for diagnostic lines 
X300 EDM 7 Issue 1 August 1994  

Climate Control Systems 
Climate Control Module Connections,  continued 
35 (16-way) Input Solar sensor 
36  (16
-way)  Input  Centre vent servo  motor  feedback po- tentiometer 
37 
(16-way) Input RH air  intake  servo motor feedback po- tentiometer F / R 
38 (16-way)  Not used 
39  (16
-way)  Input  Cool air bypass  servo motor  feedback 
potentiometer 
I 40(16-way) llnput I Coolant  temperature signal 
1 41 (16-way) llnput I RH blower motor voltage feedback 
I 42 (16-way) I Output I RH blower motor drive signal 
I 43(16-way) I Input 
I Differential  potentiometer 
44 (16
-way) Input Defrost  servo motor  feedback poten- 
tiometer 
45 
(%-way) Input  LH air intake  servo motor  feedback po- tentiometer - F / R 
46 (16-way)  Not used 
47  (16
-way) Input Foot  servo  motor  feedback potentiome- 
ter 
48 (16
-way)  Not used 
49  (16
-way) Input LH  blower  motor voltage  feedback 
50  (16
-way)  Output  LH blower motor drive signal 
51  (26
-way) Input Compressor ON  signal 
52  (26
-way)  Output  Water valve 
53 (26
-way)  Output RH Blower  motor relay 
54  (26
-way)  Output  Heated front screen relays 
55 (26
-way)  Output  Heated Door Mirror  relay 
Specification 
Open collector R = 578, connected  to 
IGN,  activated  low 
Open  collector 
R = IKn, connected to 
IG N, activated high 
Open  collector R = IKQ, connected to 
IGN, activated  high 
Voltage  /temperature  values 
Voltage 
/ temperature  values 
Open  collector 
R = IKQ, connected  to 
IGN,  activated  high 
AJ16 
- Ground  (lock sensor not fitted) 
VI2 - Ign. voltage  (lock sensor  fitted) 
Voltage 
/ temperature  values 
Voltage 
/ temperature  values 
Voltage 
/ temperature  values 
Resistance  6W. 
&IO% 
0% closed - IV, 100% open - 4V 
Resistance  6Kn 
+IO%. 
0% closed - IV, IOW0 open - 4V 
Pulse 
width modulated signal I 
OV  to 3V  max. I 
Resistance IOW. &IO%. 
Min. IV, Max.  4V 
Resistance 
6W. +IO%. 
0% closed - IV, IOW0 open - 4V 
Resistance  6W. 
+IO%. 
Resistance 6W. &IO%. 
0% closed - IV, 10096 open - 4V 
I 
Battery voltage  when compressor ON 
1  amp  at 12  volts 
Load 
36Q at  12V  IGN,  activated  low 
0 
0 
0 
0 
Issue 1 August 1994 8 X300 EDM