reset ASTON MARTIN DB7 1997 User Guide

Air Conditioning
Temperature Distribution System
The Control Panel (Fig. 4) contains:
• Fan speed-defrost rotary switch (Mode-Switch),
• Air Conditioning Function Switch
• Temperature differential rotary control
• Temperature rotary control,
The control panel relays information to the ECM.
Figure 4.
Fan Speed Control (Mode Switch)
The rotary switch controls airflow from the blower motors. The switch has five positions: 3C, 1, 2,3 and DEFROST.
«» The system is not operational; a residual signal is sent to the Electronic Control Module (ECM)
to ensure that the blower flaps are closed to prevent outside air from entering the system.

1,
2,3 Selection information is relayed to the ECM. Signals are also relayed to the ECM from the
temperature selector feedback circuits and various sensors. Fan speed is steplessly controlled
by the ECM, within the ranges 1, 2 and 3.
DEFROST the fans operate at maximum speed, front screen vents open fully, lower flaps close fully and
maximum output is directed to the windscreen (there may be a delay of up to 30 seconds from
selection to execution of this function).
Face Level Temperature Differential
This control is used to vary the temperature difference between the air coming through the face vents and that coming
through the lower vents into the footwell.
Temperature Rotary Control
This is used to preset the in car heat level in either automatic or manual mode. There are three temperature sensors
located in the system:
• Exterior ambient
• In-car
• Evaporator.
An input voltage is supplied to the sensors from AC4-13 of the control module. The temperature sensing signal from
the sensors is transmitted to the control module via AC4-4 and AC2-4 respectively. The sensors are semiconductor
devices which provide a voltage output proportional to the sensed temperature.
8-10 May 1996

'^^p
Air Conditioning
In Car Controls
Fan Speed Control Switch (Mode Switch)
SC On Mode
The system is not operational, a residual
signal to the ECM ensures that the blower
flaps are closed to prevent air entering the

system.

1.
Low Blower Mode
The fan speed is lowandtheairconditioning
function switch is fully operational. Pin 13
on the ECM is earthed through the switch
and a 12V signal is returned to Pin 44.

2.
Medium Blower Mode
The fan runs at medium speed and the
function switch is fully operational. Pin 14
of the ECM is earthed through the switch
and a 12V signal is returned to Pin 44.
3. High Blower Mode
The fan speed is high and the function
switch is fully operational. Pin 15 at the
ECM is earthed through the switch and a
12V signal is returned to Pin 44.
DEF Defrost Blower Mode
The fan speed is
high,
the function switch
and temperature switch are not operational,
front screen vents are fully open and lower
flaps are fully closed. Pin 27 at the ECM is
earthed through the switch and a 12V signal
is returned to Pin 44.
Temperature Sensors
The system has three temperature sensors:
• the ambient sensor (Fig. 5)
the evaporator sensor (Fig. 6)
Figure 5.
Figure 6.
• and the in-car aspirated sensor.
Each sensor containsa semiconductor whose output
or sensing voltage varies with temperature changes.
All three are supplied via pin 43 of the ECM. The
sensing voltages are fed back into the module via
the following pins (Fig. 7):
• ambient temperature sensor - pin 34
• in-car aspirated sensor - pin 4
• evaporator temperature sensor - pin 5
At 0°C the sensing voltage should be 2.732 volts.
This voltage rises or falls by 0.01 volts for every 1°C
change in temperature; for instance, if the
temperature rises 5°C above zero, the voltage rises
by 0.05 volts to 2.782 volts. Sensors have built in
potentiometers which are preset at the factory and
must not be adjusted.

H

Figure 7.
Key to Fig. 7

1.
Sensor

2.
Pin 43 control module
3. Sensing voltages:
Pin 4 In-car aspirated temp sensor
Pin 5 Evap temp sensor
Pin 34 Ambient temp sensor

4.
Earth-ground
May 1996 8-23

Air Conditioning
Refrigerant Recovery and Recycling ^=2?
Recovery Procedure
Hote:
Run the
air-conditioning
system
for
a
few
minutes
before starting the
recovery
procedure as
this will
enable

more refrigerant to be recovered. Turn the
system
off
before
starting
the procedure.

1.
Attach the red (high side) hose oftheunittothe high
side fitting of the system on the vehicle then fit the
blue (low side) fitting to the low side on the vehicle.
Note: Make sure that the Air conditioning
system
has
pressure in it before beginning the recovery
process;
if
there is no
system
pressure there is no refrigerant to

recover.
Also
make sure that the
oil
drain
valve
is
closed.

2. Open both the high and low side valves on the
control panel.
3. Open the red CAS (vapour) valve and the blue
LIQUID valve on the tank.

4.
Turn on the MAIN POWER switch.
5. Press the RECOVERY key on the key-pad. The
display shows that the unit in the RECOVER mode
and AUTOMATIC cycle. After the compressor starts
the display shows the weight of refrigerant being

recovered.
The compressor shuts off automatically
when the recovery is complete and the display
shows the message 'CPL' and the final weight of the
recovered refrigerant.
6. Wait for five minutes and watch the manifold
gauges for a rise above 0. If a rise occurs press the
HOLD/CONT key. Repeat as needed until the
system pressure holds for two minutes.
Note: Drain the oil
separator
after
each
job.
7. Slowly open the oil drain valve and drain the oil
into the oil catch bottle. When all the recovered oil
has completely drained close the valve.
8. Replace oil lost during the recovery procedure by
measuringthe amount of oil inthe catch bottle and
adding the same amount of new oil to the system.
Note:
Dispose
of the
recovered
oil in an approved way.
9. When the recovery tank is full the compressor is
shut off and the display shows the message FULL.
Evacuating and Recycling the Refrigerant

1.
Open the red (high side) and the blue (low side)
valves on the unit and open the red GAS (vapour)
valve and the blue LIQUID valve on the tank.

2.
Enter the required time using the key-pad, press
enter,thedisplayshowstheenteredtime in minutes.
3. Start the vacuum pump by pressing the VACUUM
KEY again. The recycling process begins
approximately five seconds after the vacuum pump
starts and the message RECYCLE is displayed.
Note: If the vacuum pump
has
run for ten hours or
over

without an oil change the
message
OIL
flashes
on the
display.
Change
the pump oil and
then press
the
SHIFT/

RESET key and
the
zero key to
reset the
oil
change
timer
to zero.
The digital display counts down the evacuation

time.

4.
Check for non-condensibles after five minutes

recycling.
Ifthegauge needles are more than lOpsi
apart purge the non-condensibles from the tank by
open
i ng
the purge valve on the back of the
un
it and
continue to bleed until both needles show the same

reading.

The vacuum sequence continues until the
programmed time has elapsed at which point the
message CPL is displayed.
5. If the moisture indicator turns green recharge with
refrigerant.
or
5. If the moisture indicator has not turned green
replace the unit's filter-drier, which is probably

saturated.

Note:
Pressing
any key at this point allows the next
function to be
accessed.

To recycle the refrigerant only without pulling a
vacuum for an indefinite period of time press the
SHIFT/RESET key and the RECYCLE key on the key­

pad.
Press the SHIFT/RESET key to cancel.
For vacuum only press the SHIFT/RESET key and
the ENTER key and then press
"1".
Run the vacuum
pump as long as required and then press
"1"
or
press SHIFT/RESET to cancel.
8-48 May 1996

^2?
Air Conditioning
System Recharging / Compressor Oil Check
Recharging the System

1.
Open the high side valve on the unit control panel.
If the messages PROGRAM and CHARGE are not
displayed press the CHG key to enter PROGRAM

mode.

2.
Key in the amount of refrigerant needed to recharge
the system and press ENTER.
3. Press the CHG key; the message AUTOMATIC and
the entered amount of refrigerant wi
11
be displayed.
The display counts down to zero as the charging
process proceeds. When the charging is complete
the message CPL is displayed.
If the refrigerant transfer is too slow the charging
unit emits a signal. If the message CHECK
REFRIGERANT is not displayed, close the high side

valve,
open the low side valve and start the air
conditioning system to pull the remainder of the
charge into the system.
If the refrigerant transfer will not complete and the
message CHECK REFRIGERANT is displayed, press
the HOLD/CONT key to interrupt the cycle then
reset the unit by pressing the RESET key. Recover
the refrigerant already charged into the system by
following the procedure for recovering the
refrigerant, add new refrigerant to the tank and
return to Step 1 to recharge the system.

4.
If the air conditioning system is not running start it
and let it run until the gauge pressure readings
stabilize (compare the gauge readings with the
system manufacturer's specifications).
Note:
Ensure
that the
readings
are accurate by closing
both the high and low side
valves
on the unit's control
panel.
5. Check the evaporator outlet temperature to make
sure that the air conditioning system is operating
properly (refer to the system manufacturer's
specifications for the proper temperature).
Compressor Oil Checic
Data
Special Tools
Sanden oil dipstick JD 149
Torque Figures
Oil filler plug 8-12 Nm
Procedure
Whenever a component has been replaced in the
refrigerator system or there is an obvious oil leak, the
following procedure should be carried out.
A Sanden oil dipstick and angle gauge are required in
order to carry out the check.

1.
Run the compressor for 10 minutes at engine idle

speed.

2.
Depressurise the system.
3. Lay the angle gauge across the flat surfaces of the
two front mounting lobes. Centre the bubble and
note the mounting angle.

4.
Remove the compressor from the vehicle.
3. Remove the plug from the oil filler hole
(1
Fig. 1).

4.
Rotate the counter weight (3 Fig. 1) on the front of
theclutchtoallowthedipstick(2 Fig. 1)to penetrate
to its fullest extent.
Figure 1.
5. Insert the dipstick to its stop position (4 Fig. 1). The
point of dipstick angle should be facing left.
6. Removethedipstickandchecktheoil levelagainst
the figures quoted in the chart below.
May 1996 8-49

^27
The Aston Martin Lagonda Diagnostic System
Users Guide
Engine Diagnostics - 97 MY
Selecting Engine Diagnostics from the Vehicle Area screen
brings up the following Engine Diagnostics Screen.
Engine Diagnostic
• Diagnostic Trouble Codes
• KOEO on Demand Self Test
• KOER on Demand Self Test
• OBDII Readiness Tests
• Output State Control
• Throttle Checks
• Exit
o
Diagnostic Trouble Codes (DTCs)
On selecting DiagnosticTrouble
Codes,
the PCM memory
will be scanned and any recorded DTCs will be decoded
and displayed.
The engine and transmission DTCs are integral to the On
Board Diagnostics (OBDII) system and are ful ly described
in the DB7 OBD II Diagnostics Manual.
Before attempting to clear the logged DTCs, record all
logged DTCs for use in subsequent fault analysis.
All logged DTCs may be cleared by selecting the EEC-V
EMS DTCs
title.
This will bring up the Clear
(C)
icon which
may be selected and confirmed to clear all logged DTCs.
Note that on clearing all logged DTCs you will also clear
the associated timers, counters and fault history files (and
extinguish the engine management warning lightfor North
American vehicles). The OBD II readines test status will
also clear down and a PI 000 (OBD II readiness test
incomplete) trouble code will be set.. A full drive cycle
(see DB7 OBD II Diagnostics Manual) must be completed
to clear the PI 000 code if required. The PI 000 code will
clear automatically after some miles of driving when all
required tests have satisfactorily completed.
Caution: If a transmission code is logged in the PCM, the
TCM DTCs must be cleared first and then clear the PCM
DTCs. If the PCM DTCs are cleared without clearing the
TCM, the TCM code will immediately reset in the PCM
when power is restored.
Key On Engine Off (KOEO) and Key On Engine
Running (KOER) On Demand Self Tests
Before either the KOEO or KOER test will run, the engine
coolant temperature must be in excess of
BO'C.
Select and
confirm either the KOEO or KOER test. If the coolant
temperature is too low, the Pre Test Engine Warm Up
screen will appear. Start the engine and run until coolant
temperature is at 80+°C.
Pre Test Engine Warm Up
Value : 41°C
80 Engine Coolant Temperature {°C)
Waiting for engine to reach
normal operating temperature
o
KOEO Test
As coolant temperature rises through the BO'C level, the
technician will be requested to turn the ignition off and
then on again. The KOEO test will then commence. Static
inputs to the PCM will be checked and any faults detected
will be recorded and displayed as DTCs. If any DTCs other
than PI 000 are logged, go to the OBD II Diagnostics
Manual and resolve the concern(s) using the OBD 11
diagnostic procedures.
KOER Test
If coolant temperature level is below 80°C, the technician
will be prompted to start and run the engine until coolant
temperature rises above 80°C. As the temperature passes
the 80°C
level,
the KOERtest will commence automatically.
If coolant temperature is above the 80°C level, the
technician wi
11
be requested to start the engine. The KOER
test will commence as the engine is started. Dynamic
inputs to the PCM will be checked and any faults detected
will be recorded and displayed as DTCs. If any DTCs other
than PI 000 are logged, go to the OBD 11 Diagnostics
Manual and resolve the problem(s) using the OBD II
diagnostic procedures.
September 1996 9-33

ffi:
The Aston Martin Lagonda Diagnostic System
Users Guide
Idle Fuelling Trim - 95 MY
This program is used to check and if necessary reset the
fuelling level at idle to ensure that the specified idle speed
and emission levels are attainable. The throttle
potentiometer adjustment sequence must be completed
before the fuel trim sequence can be run.
Note: The throttle setup must be completed before
attempting to set the Idle Fuelling Trim. An error in
throttle
stop,
throttle cable or throttle pot
adjustments can
cause serious
difficulties in setting the Idle Fuelling.
Select Idle Fuelling Trim from the Engine Setup

Menu.
(The PDU connections are
as
fortheThrottle
Potentiometer Adjustment.)

1.

3.
StarttheDB7engineand allow itto warm to normal
operating temperature.
Followthescreeninstructionstorunthe idle fuelling
trim procedure.
Observe the bargraphs for oxygen sensors A and B.
The bargraph indications should oscillate evenly
about the 0% position on the bargraph.
BANK

-100%

BANK

-100%

Idle
Fuel
Trim
Closed Loop Control Data
Q Idle
trim:
8%
9^B 1 1
Oxygen Sensor Fuel Trim 100%
B Idle
trim:
5% —1 1 1

«^
1 1 Oxygen Sensor Fuel
Trim
100%
Idle Fuelling Trim Display
5. Ifthebargraphindicationsarenotoscillatingevenly
about the 0% position, select the A (cylinders 1, 2
and 3) or the B (cylinders 4, 5 and 5) sensor. The
Increase/Decrease buttons will appear.
6. Adjust the fuel trim as required to achieve even
oscillation about the 0% mark for both sensors.
When the adjustment is correct, select the 4 icon
and confirm that the idle fuelling trim is correct. On
confirmation of the adjustment, the PDU will exit
from the idle fuelling program.
7. On completion of the procedure, select Exit from
the Engine Diagnostics Software.
September 1996 9-39

^
The Aston Martin Lagonda Diagnostic System
Users Guide
Parameter Name
Parameters can be fault codes, inputs to, or specific
outputs from, a vehicle control module.
The number of parameters selectable is limited to 32.
If the number of parameters available for customization
exceeds the d isplay
area,
the arrow buttons wi
11
be present,
allowing display area scrolling.
The parameters declared to Datalogger are initially
presented in alphabetical order.
Record Enabled
Record enabled is used to select which signals are to be

recorded.

To select a signal for recording, touch the rectangle next
to the signal name.
The record button will then be displayed.

Nofe:
Additional rectangles may appear in other columns
beside a selected signal name, indicating that the signal
units may be changed or that the signal may be used
as
a

trigger.

It should be noted that the more parameters you select to
record the slower the PDU's sample rate will be for each
parameter e.g. The PDU may be able to monitor six
parameters sampling each parameter twice a second. If
the number of parameters is increased to twelve then the
PDU would only be able to sample each parameter once
per second, thus reducing its ability to capture fast faults;
therefore it
is
recommended that the number of parameters
is kept to a minimum.
Display Order
Parameters may be displayed on the waveform/ bargraph
screen in any order.
To set the parameter display order, press the required
rectangle to create a numbered list.
Note: It
is
not
necessary to
display all of the parameters
required to be recorded.
This has particular benefits if a parameter is to be used as
a trigger but is not required to be displayed.
Trigger Action
For a detailed description of trigger action, refer to the
Trigger Customisation description on the following page.

S.I.
Units
Certain parameters can be measured / displayed in a
number of different units eg temperature in °C or °F. If a
rectangle appears around the displayed units in the
'S.I.'

column then the units are selectable. Each time the
rectangle is pressed, the selectable units scroll one step
through the available options.
Other Features
To make parameter customization easier two icons have
been introduced on to the bottom of the screen, these are:
This icon simply puts all ofthesignals selected for
recording in alphabetical order irrespective of
the language.
A B C
This icon will put all of the signals selected for
recording at the top of the parameter list in
numerical order.

^T/^

After the parameter customization process is completed,
return to the Datalogger main menu.
Default Customisation
To cancel all customisations, press the
Customisation Reset
icon.
This will reset the
customisation on all parameters to the default

setting.

Trigger Customisation
Datalogger operates using a 'rolling memory'.
When the Record icon is selected on the waveform
display, PDU will start to record data, it will then continue
to record data until its memory is
full.

At this point it will continue recording by overriding the
oldest
data.
This process will continue indefinitely or until
the trigger is activated.
When the trigger is activated it performs a number of
functions.
a) The first function istoplaceazerotimepointwithin
the stored data, this enables the trigger point to be
easily accessible in later stages.
b) The second function is to set a timer, ensuring that
the PDU wil
I
only continue recording for the time
selected in 'test-duration'.
September 1996 9-57

5'=3^
The Aston Martin Lagonda Diagnostic System
Users Guide
The 'tick' icon was selected to return to the trigger screen
which will then be as shown below.
ABSWL
Trigger
Anti-Lock Bra
^ CTD
AJUJ
^B
6V
.J7.
!•
t 1
•
S.I.

fvl
^ t

]

kes Warning Lamp
Z-.Z4
The Trigger Set-Up Screen
The 'tick' icon was then selected to return to the parameter
customisation
screen.
The screen should now look similar
to that below.
Signals • cn> J^ [Z^ S.L
RLW<133
RRW<133
BAT+P20
BAT+P3
FLS2
FLW<133
•
V
KPH
KPH
V
V
^ Kr-
i c
V
KPH
ini
Parameter Customisation - Final Setup
The 'tick' icon was pressed to access the waveform
display.
The PDU was now ready to start recording data.
The 'record' icon was selected to start recording data.
When the fault occurred, the ABS warning lamp
automatically triggered the PDU. This will place a fixed
cursor on the screen and set the time base to zero. The
PDU will stop recording after the preset record time. If no
record time has been entered, the PDU will use its default
record time of 16minutes and 40 seconds. 8m20s pre-
trigger and 8m20s post trigger.
The following figure indicates the typical waveform display
for the wheel speed sensor fault. The dotted vertical line
represents the trigger point.
16V
ABSWL
OV
240KPH "
RLW<133
OKPH .
240KPH •
RRW<133
OKPH
-55.4s
7.29s
^ 39.6s
^ MMV
\!MV
m

wheel Speed Sensor Display
September 1996 9-65