
IW Automatic Transmission (AJ16) 
TRANSMISSION  FLUID TEMPERATURE  SENSOR INPUTS P 0712 / P 0713 
The transmission  fluid temperature  sensor is a positive  temperature coefficient  thermistor bead, located in the internal 
wiring  harness  of the transmission assembly  and immersed in the transmission  fluid in the unit  sump.  The wiring  is 
taken  out through  the transmission connector and  runs through the rotary switch and  then into the gearbox  harness 
to  the  TCM.  The pin outs  on the  relevant parts  are as follows. 
TCM  ROTARY SWITCH  TRANSMISSION 
55 WAY CONNECTOR  12 WAY  MULTI-LOCK 9 PIN  DEUTSCH 
(CC007) (GB002) (GB003) 
PIN 46 - SIGNAL  PIN 8 -SIGNAL  PIN D -SIGNAL 
PIN 
44 -GROUND  PIN 9 - GROUND  PIN J -GROUND 
TRANSMISSION FLUID TEMPERATURE  SENSOR LOW INPUT- P 0712 
This input  is continuously  monitored during initialization  and operation by the  processor  and is checked against spe- cific  limits  to be  in range. If the  temperature indicated by  the sensor  is too low then this fault  code will be stored and 
the  processor  will use a substitute value  for the transmission  oil temperature. 
The  low limit  is approximately 
-50" C. This  fault  would  indicate  that the output signal line  (Pin 46) is probably short 
circuit  to ground. 
TRANSMISSION  FLUID TEMPERATURE  SENSOR HIGH INPUT- P 0713 
This input  is continuously  monitored during initialization  and operation by the processor and is checked against  spe- cific limits to  be in range. If the  temperature indicated by  the sensor  is too high  then this fault  code  will be stored and 
the  processor  will use a substitute value  for the transmission  oil temperature.  The high  limit is approximately 185" C. 
This fault  would  indicate  that the input  signal  line (Pin 46) is probably open  circuit or short circuit  to battery  positive 
voltage (+I2 nominal). 
Possible causes: 
. Faulty  sensor. 
. Faulty harness  wiring or connection  to sensor. 
Effects: 
. Substitute  oil temperature adopted by  TCM. 
Remedy: 
Renew internal  harness. 
. Repair or renew  harness I connectors. 
Issue 1 August 1994 8 X300 EDM  

Automatic Transmission (AJ16) 
OUTPUT SPEED SENSOR - P 0721 / P 0722 
The output  speed sensor is located  on the  rear  of thevalve block  assembly  inside the transmission. Connection  is made 
via  pins  A and F of  the %way transmission connector located  on the left hand side  of the transmission  assembly. The 
wiring  runs through  the rotary  switch  harness  and the vehicle gearbox  harness to the  TCM  on pins 2 and  38 of the 55 way multi-plug.  These  wires are shielded by a screen  which is terminated  on pin  20 of the  TCM multi-plug.  The sensor 
detects  the motion of  the output shaft via a 36 toothed  wheel. 
TCM  ROTARY SWITCH  TRANSMISSION 
(CC007) (GB002) (GB003) 
PIN 2 -SIGNAL  PIN 11 -SIGNAL  PIN F -SIGNAL 
PIN 38 
- GROUND  PIN 12 -GROUND  PIN 
A - GROUND 
OUTPUT  SPEED SENSOR  CIRCUIT  RANGE/  PERFORMANCE - P 0721 
This test is  only performed  when a downshift takes place  and therefore the vehicle must  be in a forward gear ie D, 3, 2, 1. A fault  will be flagged  if the  engine  speed is above a threshold  which is dependant  on the shift  and the state of the  lock  up clutch. 
This  fault  code  would  suggest  that there  is  an intermittent fault  in the  circuit. 
OUTPUT  SPEED SENSOR  CIRCUIT  NO SIGNAL - P 0722 
The  background diagnostic software continuously  monitors the output speed and flags  this fault if the output  speed 
is  zero  when  the engine  speed is greater  than 2000 rpm and a forward  gear, D, 3,2,1, is selected. 
This  fault  code  would  suggest 
a permanent fault, either open circuit, short  to ground or  short circuit  to battery  positive 
voltage (+12V nominal). 
Possible causes: 
Faulty  sensor. 
Faulty  harness  wiring I connectors. 
Effects: 
MIL illuminated. 
Transmission  warning lamp  illuminated. 
Maximum pressure applied. 
Limp home  mode  applied. 
Remedy: 
Renew sensor. 
Repair  or renew  harness I connectors.  ~~~~  ~~ 
Issue 1 August 1994 10 X300 EDM  

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  

lw Automatic Transmission (AJ16) 
SYSTEM VOLTAGE  MALFUNCTION - P 1794 
The TCM  monitors  the supply voltage and  will log this fault if the voltage is  less than 10.5V when  the engine  speed is 
greaterthan 1600rpm. This  fault  code  is unlikelyto becaused by afault  within theTCM and assuch thevehicle  harness 
and fuses  etc. should  be completely tested before  the TCM  is condemned. 
Possible causes: 
. Blown  fuses. 
. Faulty harness  wiring /connections. 
Effects: 
Transmission default settings  adopted. 
. MIL illuminated. 
Transmission warning lamp illuminated. 
. Maximum fluid pressure  available. 
. Limp home mode applied. 
Remedy: 
Examine fuse  F14 in LH heelboard fuse-box.  Renew (if necessary)  after determining  cause of rupture. 
. Repair  or renew  harness / connector. 
KICK-DOWN  SWITCH  SYSTEM - P 1796 
The diagnostic  check on the mode  switch input  is a plausibility check which  is performed continuously  while in oper- ation.  A fault  is determined when kickdown is  seen when  the throttle  angle is less than 50%. However a fault  will only 
be  logged  if the output  speed is greater  than 256 rpm.  No fault is logged  if there  is already a throttle  signal fault.  The 
kickdown switch  is located  on the  floor  under  the accelerator  pedal and is operated when  the throttle  is fully open (ap- prox 90%). It is a normally  open switch  with one contact permanently  to ground  and the other is a signal to the TCM. 
The  signal  wire is routed  through the  bulkhead harness and the gearbox  harness to the  TCM. 
LHD 
(FCO19) PIN 2 GROUND  PIN 1 KD 
SIGNAL 
RHD 
(CA074) PIN 2 GROUND  PIN 1 KD 
SIGNAL 
Possible causes 
. Faulty harness  wiring /connections. 
. Faulty switch  (or switch  adjustment). 
Effects: 
No kickdown facility. 
Remedy: 
. Repair or renew  harness  /connector. 
. Re-adjust or renew switch. 
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Issue 1 August 1994 24 X300 EDM  

Automatic Transmission (V12) Powertrain 
Engine Speed 
The engine  speed is provided by  an open collector  signal supplied  from the engine  management  control module 
(ECM). 
Throttle Position 
This signal,  from the ECM,  performs the  following two functions: 
1. 
2. 
Engine  Torque  (and warm-up) 
This signal,  from the ECM,  performs the  following three functions: 
1.  During  cranking  to convey  the completion  of an  engine warm
-up  cycle  to TCM. 
2. To  convey engine  torque information,  under normal running  conditions, to TCM. 
3. To  convey engine  torque fault signals to TCM. 
Engine ‘warm
-up’  cycle commences  from ignition ON until 500ms after the engine  exceeds 400rpm. After this time 
delay  either  an engine torque,  or torque  fault signal  will be transmitted. 
Transmission Input Speed 
The  transmission  input speed sensor  is mounted  within the transmission housing  and produces a variable frequency 
signal,  directly  proportional  to forward  clutch housing rotational  speed which  is transmitted  to the  TCM.  Sensor resis- tance equals 1.25kQ f 0.25. 
Transmission  Output Speed 
The transmission  output speed sensor is mounted  within the transmission housing  and produces a variable frequency 
signal,  directly  proportional  to the  rear carrier  rotational speed which  is transmitted  to the  TCM.  Sensor resistance 
equals 
1.25w2 + 0.25. 
hake Application 
When a brake  application signal  is received, due  to brake  switch  operation,  the torque  convertor clutch  lock-up sole- noid  is de-energized,  releasing lock-up mode  if already  applied 
Transmission  Oil Temperature 
The  transmission oil temperature  sensor, located within the internal  harness,  monitors  oil temperature  and transmits a corresponding signal  to the  TCM. 
To convey  throttle position information  to the  TCM. 
To  indicate  fault conditions  between ECM and throttle  potentiometer. 
8.2.4.2 OUTPUTS 
Gear  Shift Solenoids 
The two  gear  shift solenoids, located  within the transmission  housing, determine  gear ratio  when  the selector  is in  any 
of the forward  gear positions. 
Force Motor 
The force  motor,  mounted within the transmission  housing acts as a transmission  torque fluid pressure regulator. 
Torque  Converter  Clutch (TCC) Solenoid 
The torque converter clutch  solenoid, mounted within the transmission  housing, provides a direct drive from the en- gine, via  the converter  clutch, to the driven  wheels, giving the  efficiency of a manual  gearbox.  The  solenoid also pro- vides a  ’ramp‘ apply and  release to engage / disengage  the clutch  gently. 
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X300 EDM Issue 1 August 1994 6  

Automatic Transmission (V12)  ~ Pow. rtrain 
Engine 
Torque  Reduction and  Malfunction Indication 
This signal,  to the  ECM,  has three modes  of operation. 
1. To  indicate  normal engine operation  to the  ECM. 
2. During  gearshifts,  to request  reduction  of engine  torque 
3. During fault  conditions, to inform  the ECM. 
During normal  operation 
theTCM outputs a constant  duty cycle  signal  to the  ECM.  The signal  is changed  when torque 
reduction  is required  to indicate  to the  ECM  the degree  of ignition  retardation  necessary.  If a fault  condition,  relating 
to  OBD 
II CARB  legislation,  occurs  the TCM will transmit  a signal  to the  ECM  relating  this event.  The ECM will only 
respond  to this  signal if its duration  is 100 milli-seconds or longer. 
If the  signal  from the torque reduction line  is either HIGH or LOW for 2 or  more  seconds  the EMS will recognise  that 
a  fault  may be present and  transmit this information  to the  TCM. 
If the  signal  from the torque  reduction line lasts  for 2 or more  seconds  the EMS will return  to normal  operation. 
Sport Mode  Indicator  Lamp 
The sport  mode  indicator  lamp, mounted  on the  instrument  panel, is illuminate when  sport mode  is selected  and the 
ignition  switch is ON. Sport mode  is selected  at a two  position switch  mounted to the  rear  of the  gear  selector  assembly. 
Gearbox Failure Warning  Lamp 
The gearbox failure  warning lamp, mounted on the  instrument panel, is illuminated  when afault is  detected bytheTCM within the transmission  electrical or mechanical systems. 
Vehicle  Speed (12 cylinder  vehicles only) 
This output  signal is  calculated  from the transmission  output speed and  supplied to the  ECM  as an  indication  of vehicle 
speed. 
8.2.5 DIAGNOSTIC  LINKS 
Diagnostic 
L line 
One of a  two  wire  interface used  to activate  stored diagnostic  codes for reading  by external  equipment. 
Diagnostic K  Line 
One of a two-wire interface  used to communicate  stored diagnostic  codes for reading  by external  diagnostic equip- ment. 
X300 EDM 7 Issue 1 August 1994