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
Electrical rl
SECTION CONTENTS
Sub-Section 15.4 Driver Ergonomics
Sub-Section Title SRO Page
15.4 ............. Driver Ergonomics .............................................................. 15.4- 1
15.4.1 ............ System Description .............................................................. 7 5.4- 1
15.4.1.1 .......... Entry/ExitMode ................................................................ 15.4-1
15.4.1.2 .......... Driving Position Set ............................................................. 15.41
15.4.1.3 .......... PassengerSeatSet ............................................................... 15.4-1
15.4.1.5 .......... Reverse Mirror Dip .............................................................. 15.4-3
15.4.2 ............ System Components ............................................................. 15.4-3
15.4.2.1 .......... Seats - Driver and Passenger ...................................................... 7 5.4-3
15.4.2.3
.......... Seat Lumbar Pump .............................................................. 15.4-3
15.4.1.4
.......... RemoteRecall .................................................................. 15.43
15.4.2.2 .......... SeatMOtors .................................................................... 15.43
15.4.2.4 .......... Seat
Heaters and Thermostats ..................................................... 15.4-3
15.4.2.5 .......... Seatswitch Pack ................................................................ 75.45
15.4.3 ............ Seat Control Module ............................................................. 15.45
15.4.3.1 .......... Seat Control Module Connector Pins ............................................... 15.4-6
15.4.4.1 .......... Column Motors ................................................................. 75.48
15.4.4.3 .......... Driver / Passenger Rear View Mirror Motors ......................................... 15.4-9
15.4.4 ............ Steering Column /Mirror ......................................................... 75.48
15.4.4.2 .......... Column Joystick Switch .......................................................... 15.48
15.4.4.4 .......... Mirror joystick .................................................................. 15.49
15.4.5 ............ Column/Mirror Control Module ................................................. 15.4-10
15.4.6 ............ Non-Memory and Manual Applications ........................................... 15.4-12
15.4.6.1 .......... Non-Memory ................................................................. 15.4-12
15.4.6.2 .......... Manualseats .................................................................. 15.4-72
15.4.6.3 .......... Manual Column ............................................................... 15.4-12
15.4.7 ............ Symptom FlowChafls .......................................................... 15.4-13
15.4.8
............ Diagnostic Sub-routines ........................................................ 15.4-17
15.4.9.16 ......... Key to Schematic Diagrams ...................................................... 15.4-35
15.4.9 ............ Pin-Point Tests ................................................................. 15.4-19
15.4.10
.......... Electrochromatic Rear View Mirror ................................................ 15.4-36
15.4.10.1 ......... Description ................................................................... 15.4-36
15.4.10.2 ......... Test Procedure ................................................................. 15.436
X300 EDM V Issue 1 August 1994
15.4 DRIVER ERGONOMICS
15.4.1 System Description
Adjustment of the seats, steering column and exterior rear view mirrors position is effected by means of control
switches. The switches maintain the adjustment facility while depressed, movement ceasing when the switch is re- leased.
Manual adjustment can be achieved either with the ignition key in place or with the driver‘s door open, or having been
closed within the last
30 seconds.
The system offers the following facilities:
Entry
/ Exit mode; an automatic seat /column position setting for ease of driver entry into / exit from the vehicle.
Driving position set; automatic recall of up to three preferred settings.
Passenger seat set; automatic recall of up to three preferred settings.
Remote recall; automatic recall of up to two memory positions from
a remote transmitter (in key fob).
Reverse mirror dip; automatic adjustment of passenger rear view mirror when reversing.
U: Vehicles intended for the Japanese market are fitted with an additional ‘fold away’ mirror function. This func- tion allows mirrors to fold flat against the car when parking in enclosed areas.
15.4.1.1 Entry/ Exit Mode
Entry / Exit mode is designed to give easier vehicle entry and exit for the driver. The facility is selected by positioning
the mode switch, located on the LH side of the column cowl, to ‘auto’ which designates the current seat / column posi- tion, ie driving positions, as the memorized position. On removal of ignition key or opening of driver‘s door, with igni- tion key still in place, the driver’s seat will move to the rear (current position allowing) and the column will adopt ‘tilt
away’ mode automatically creating additional space for driver exit
/ entry. Insertion of key in ignition or closure of
driver‘s door (with ignition key in place) returns seat / column positions to the memorized (previous) position.
Operation of eitherthe brake pedal or
seat/column manual controls during entry/exit mode execution will abort posi- tional adjustments. Setting the mode switch to OFF disables operation of entry / exit mode.
15.4.1.2 Driving Position Set
Setting of seat, column and external rear view mirrors to preferred driving position is available using the memory but- tons located on the drivers door switch pack. With the ignition key in place enter settings to be memorized as follows:
Adjust seat, column and mirrors to desired positions.
Press the ’memory’ button
so that it becomes illuminated.
Press button
1,2 or 3 to store configuration within four seconds of memory button operation. Memory light will extin- guish and a chime will sound, indicating procedure complete.
The above procedure may be repeated two more times until each button
(1,2 & 3) has a preferred position stored in
memory, accommodating different driver settings. Operation of any push-button (1,2 or 3) will re-position seat col-
umn and mirrors to the stored settings.
Memory recall will operate under the following conditions:
. Ignition key in and gear selector in park.
8 Ignition key in and handbrake on.
8 Ignition key out and driver’s door open (or having been closed within the last 30 seconds).
Re
-setting the preferred position on any setting button automatically erases previously stored information. Memory
information is not erased if power supply to the seat and column / mirror control modules is lost (e.g. battery discon- nected).
15.4.1.3 Passenger Seat Set
The procedure for setting and recalling a preferred passenger seat position is identical to that for a driving position.
Memory recall will only operate with ignition key in auxiliary position or passenger door open, or having been closed
within the last
30 seconds.
X300 EDM 15.4 - 1 Issue 1 August 1994
rl E I ect r ica I
1 12
186 1777
1. Driver's seat assembly 7. Column tilt motor
2. Passenger's seat assembly
8. Column reach motor 3. Driver's door switchpack 9. Column joystick! mode switch 4. Passenger's door switchpack
10. Driver's door mirror
5. Driver's seat control module 11. Passenger's door mirror 6. Passenger's seat control module 12. Electrochromatic rear view mirror
I Fig. 1 Seat, column, mirror adjustment system
0
0
0
0
15.4.1.4 Remote Recall
Remote activation of memory positions 1 and 2 can be achieved using the key fob transmitters (one per set of keys).
lfthe vehicle is unlocked using the remote transmitter the stored driving position will be adopted automatically. If the
vehicle is unlocked using the remote transmitter and an exit position is already set the corresponding entry position
will be adopted until the ignition key is inserted, the stored driving position will then be restored. 0 ~
15.4.1.5
Reverse Mirror Dip
On selection of reverse gear and operation of the mirror toggle switch downwards, the passenger side rear view mirror
will automatically tilt downwards to assist reverse parking. Upward adjustment disables reverse dip, a further down- ward adjustment when still in reverse gear reinstates reverse dip. The mirror will return to normal position when any
other gear position is selected.
15.4.2 SYSTEM COMPONENTS
15.4.2.1 Seats
- Driver and Passenger
The driver and passenger seat adjustment systems comprises the following components:
o Fore / aft motor
o Front raise / lower motor
o Rear raise / lower motor
0 Squab recline motor
0 Headrest motor
0 Lumbarpump
0 Squab heater
0 Inner cushion heater
0 Outer cushion heater
0 Heater thermostat
0 Switch pack
o Seat Control Module (SCM)
o Wiring harness
15.4.2.2 Motors
The five seat position adjustment motors are located below the seat cushions (horizontal and vertical adjustment) and
behind the squab (recline and headrest adjustment). Each motor unit incorporates a potentiometer which provides
directional movement position control via feedbackvoltage variations to the SCM. Positional variations are activated
by the SCM in response to signals from switches mounted on the seat switch pack.
15.4.2.3 Lumbar Pump
The lumbar pump, located behind the seat squab allows adjustment of seat rigidity by increasing/decreasing air pres- sure in the lumbar pad. The pump motor is controlled from a switch on theseat switch pack and governed by an in-line
pressure switch.
A solenoid valve is used to regulate air flow to the lumbar pad.
15.4.2.4 Heaters and Thermostats
The two cushion heaters and squab heater are regulated by a single in-line thermostat and operated by a switch
mounted on thecenter console switch pack. Operation of this switch causesthe Body Processor Unit (BPU) to energize a timed input to SCM (for 11 minute f 1) which in turn causes SCM to energize the heater supply. The supply will
remain on until timed out, although the heater circuit will be broken by the thermostat if the set temperature is ex- ceeded.
Note: Heatingcan only occur when the ignition switch is position I1 and the ambient temperature is belowthe thermo- stat pre-set value of 26°C.
X300 EDM 15.4 - 3 Issue 1 August 1994
Electrical rl
15.4.4.3
The rearview mirror motors are located within the mirror assemblies, immediately behind the glass in a sealed assem- bly. An additional motor, mounted above the fixing bracket, or foot provides rotational mirror movement from fully
extended to folded flat to the car.
Elnfe:
Driver / Passenger Rear View Mirror Motors
Fold away movement motors are fitted to Japanese market vehicles only.
15.4.4.4 Mirror Joy-stick
The mirror joy-stick are located in the driver’s switch pack, providing inputs to the C/ M CM which operates the relevant
motor accordingly. A mirror select switch determines which mirror is adjusted when the joy-stick is operated.
2
5
1. Mirror movement motors 2.
3. Motor harness 4. Harness connector
5. Mirror glass 6. Mirror housing
7. Mounting foot
Fold away
motor (Japan only)
/ manual fold-back pivot
Fig. 1 Rear View Mirror Assembly
J86-1921
X300 EDM 15.4 - 9 Issue 1 August 1994
E I ect r ica I
15.4.7 SYMPTOM FLOW CHARTS
The following test procedures are designed to test the system as a whole, identifying faulty areas and indicating poss- ible solutions by functional operations.
During all test procedures the entry
/ exit mode switch must be OFF.
The first three test procedures listed i.e. drivers seat position adjustments, steering column position adjustments, rear
view mirror position adjustments must be carried out four times, each time under one of the conditions stated below:
Key in ignition barrel
Ignition key in auxiliary position
Driver’s door open with ignition key out
Driver’s door closed within the last 30 seconds with ignition key out.
0
Driver‘s seat position adjustments
1.
2.
3.
0
4.
5.
6.
7.
0
Locate seat switch pack on the side of the seat cushion.
Operate the fore
/ aft movement control switch. Does the seat respond in the correct
manner?
Yes: Proceed to step 3.
No:
Operate front and rear, raise / lower movement control switches. Does seat respond in the
correct manner in each case?
Yes: Proceed to step 4.
No:
Operate squab recline / incline movement control switch. Does squab respond in correct
manner?
Yes: Proceed to step 5.
No:
Operate lumbar pump inflate / deflate control switch. Does lumbar pad stiffen and slacken
according
I y?
Yes: Proceed to step 6
No:
Operate headrest raise / lower switch. Does headrest respond in correct manner?
Yes: proceed to step
7.
No:
Remove key from ignition, close driver‘s door and allow 30 seconds to elapse. Repeat
steps
1 - 6 and check that adjustment cannot be made.
Test complete; proceed to Memory Position Set.
Abort
test and refer to Diagnostic Sub
-Routines.
Abort test and refer to Diagnostic Sub
-Routines.
Abort test and refer to Diagnostic Sub
-Routines.
Abort test and refer to Diagnostic Sub
-Routines.
Abort test and refer to Diagnostic Sub
-Routines.
Steering column position adjustments
1.
2.
Locate steering column joystick switch the LH side of the column.
Operate switch to give fore
/ aft movement. Does the column respond in correct manner?
Yes: Proceed to step 3.
No:
Operate the switch to give raise / lower movement. Does column respond in the correct
manner in each case?
Yes: Proceed to step 4.
No:
Remove key from ignition, close driver’s door and allow 30 seconds to elapse. Repeat
steps 1
- 3 and check that adjustment cannot be made.
Test complete; proceed to Memory Position Set.
Abort
test and refer to Diagnostic Sub
-Routines.
3.
Abort test and refer to Diagnostic Sub-Routines.
4.
5.
X300 EDM 15.4 - 13 Issue 1 August 1994
Rear view mirror position adjustments
1. Locate mirror select switch on driver's door switch pack and select driver's side mirror, ie
rotate switch towards the door.
2. Locate rear view mirror joystick switch on driver's door pack.
Operate the switch to give left
/ right and up / down movement. Does the mirror respond
in the correct manner?
3. Yes: Proceed to step 4 or 5.
No:
Japanese market vehicles only
Operate the switch to action 'fold away mode'. Does mirror respond in the correct manner
in each case?
Yes: Proceed to step
5.
No:
All markets
Operate mirror select switch to opposite position and repeat steps
1 to 4 for passenger side
mirror.
With ignition switched to auxiliary, select reverse gear and operate mirror joy
-stick
downwards. Does passenger side mirror dip automatically?
Yes: Proceed to step
7.
No:
Remove key from ignition, close driver's door and allow 30 seconds to elapse. Repeat
steps
1 - 6 and check that adjustment cannot be made.
Test complete; proceed to Memory Position Set.
Abort
test and refer to Diagnostic Sub
-Routines.
4.
Abort test and refer to Diagnostic Sub-Routines.
5.
6.
Abort test and refer to Diagnostic Sub-Routines.
7.
8.
Memory set position - drivefs side
1.
2.
3.
4.
5.
6.
7.
8.
Position the entry / exit switch, located on the LH side of the steering column, to off and
insert the key in the ignition.
Operate switches to position column, mirrors and seats to preferred positions.
Select 'memory' on the driver's door switch pack. Check that switch illuminates.
Depress desired memory button,
1,2 or 3, on door switch pack within 4 seconds of
memory select. Check that a chime sounds to confirm memory storage.
Operate the switches
so that memorized positions are changed. Depress relevant memory
option button,
1,2 or 3 and check that all positional settings are restored as memorized.
Remove key from ignition, close all doors and allow
30 seconds to elapse. Repeat steps 1
to 4 and check that adjustment cannot be made.
Readjust settings so that memorized positions are changed, leave the vehicle and operate
remote memory recall by locking and unlocking using the remote transmitter. Use both
transmitters to check both memory positions. Check all positional settings are restored as
memorized.
Yes: Proceed to step
8.
No:
Test complete. Abort
test and refer to Diagnostic Sub
-Routines.
X300 EDM Issue 1 August 1994 15.4 - 14