
Automatic Transmission (AJ16) 
TP ELECTRICAL  SIGNAL SYSTEM - P 1791 
If the throttle  angle signal  line is held  permanently  high or low  for more than looms, then this  fault will be recognised 
and stored.  The TCM  will adopt  the substitute  throttle value and turn on the warning  lamp. The fault  code  will only  be 
stored if the engine  speed is greater  than 400rpm. 
TCM PI HARNESS  ECM 
CC007/047 P1063/00 1 PI 1041032 
Possible causes: 
Faulty harness  wiring I connection. 
. Faulty ECM signal. 
Effects: 
Transmission  warning lamp  illuminated. 
. MIL illuminated. 
Normal mode only available. 
Substitute  throttle angle adopted. 
No kickdown facility. 
Remedy: 
Repair or renew  harness 1 connector. 
Examine ECM fault diagnosis (refer  to EDM,  Section  5.1). 
TP SIGNAL  SYSTEM  RANGE/  PERFORMANCE - P 1790 
The throttle  signal is a pulse  width  modulated (pwm) input which runs at a constant frequency  of 183 Hz the information is contained  in the duty  cycle of the signal. If this  information  is out of range,  that is, the  duty cycle  is less  than  5% or 
greater  than 94%, then the  TCM will use a substitute  throttle value of  47% and will light  the warning lamp  and this fault code  will be stored.  During cranking,  this signal  is used  to convey  the engine coolant temperature.  The coolant  tem- perature signal  persistsfor 500 msec after reaching  the engine  run threshold  of 400  rpm.  If theTCM does not recognise a valid  throttle  angle signal  afterthis time  then a substitute throttle value (47%) will be used  and the warning lamp  will 
be 
lit and  this  fault  code  will be stored.  A fault code will only  be stored if the  engine  speed is greater  than 400 rpm. If an out  of range coolant temperature  is received  then a substitute coolant temperature value (77" C) is used  but no fault is stored. 
X300 EDM 21 Issue 1 August 1994  

Automatic Transmission (V12) Powertrain 
8.2.3 OPERATING PRlNClPL ES 
The electronic  control system  is split  into four  main functional  areas: 
0 Shift Point  Control 
0 Lock-up Control 
0 Pressure  Modulation 
0 Engine Torque  Control 
0 
Shift Point Control 
The optimum  gear ratio  is selected  as a function  of transmission  output speed,  engine  load, position  of selector  switch 
and  program  switch. 
Lock-up Control 
The torque  converter clutch  is engaged  as a function  of load,  output  speed,  gear selected  and drive program.  Lock-up 
is  possible  in second,  third and fourth  gear. Apply and  release quality is controlled by the  pulse  width  modulated  pres- 
sure regulator solenoid. 
Pressure Modulation 
Hydraulic pressure in the  transmission shift  friction elements  is accurately  matched to transmission  output torque 
using an  electrically  operated solenoid valve  to control  pressure level.  Transmission input torque is calculated  from 
an output torque  value, supplied  by EMS,  and converter  slip. 
Engine Torque Control 
Engine torque control  reduces the energy dissipated  within the system  during gear shifts.  The effect  of this control 
increase  the transmission  service life by reducing slippage  time, increases  comfort by reducing  clutch torque  trans- mission and allows  a greater transfer  of power by  the transmission unit. 
8.2.4  INPUTS / OUTPUTS 
8.2.4.1  INPUTS 
Transmission  Range 
The transmission  range is detectec ,ythe pressureswitch manifold  located within the transmission unit. The  manifold 
transmits  a coded  message  to the  TCM  indicating  gear selector  position. 
Performance Mode Select 
Performance  mode select  uses a  two wire input to the  TCM  allowing  selection  of different transmission operating 
modes. 
Line  A; Used  for selection  of traction  control shift  pattern and controlled 
by the ABS  /TC CM. 
Line 
B; Used  for selection  of 'Normal'  or 'Sports'  mode, manually  selected at a two  position  rocker switch mounted 
on  the  gear selector unit. Switch  resistance  is equal  to or greaterthan look$, open circuit and  equal to or  less  than 0.5$ closed  circuit,  measured  across contacts at  a current  of 10mA. 
Kickdown  Switch 
This signal  is controlled  by the  operation ofthe kickdown  switch on depression  of the  accelerator  pedal to its full extent. 
The  switch  remains in 'normally  open' position until  contact with the pedal closes  the contacts.  Switch resistance  is 
equal  to or  greater  than look$, open circuit,  and equal  to or  less  than 0.5$ closed  circuit, measured  across contacts at 
a  current  of 
10Ma. 
Calibration  Select 
The calibration  select input allows  identification  of different  vehicle specifications, ie 4.0 liter supercharged,  or 6.0 liter (V12). The link,  to ground,  from the TCM  is either  short or open  circuit, dependant  upon internal software calibration 
for  each  vehicle variant. 
X300 EDM 5 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