buttons ASTON MARTIN DB7 1997 Workshop Manual

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
Climate Control Diagnostics
The air conditioning control module is located at the right
end of the air conditioning unit. Since this controller uses
a unique communications protocol, the PDU must be
connected directly to the unit via the Vehicle Inerface
Adaptor as shown in the following cable setup screen.
Cable Setup
Adigitalmicroprocessorwithin the control module receives
data signals from the operator controlled switches.
Comparison of these signals with those returned from
system temperature sensors and feedback devices results
in the appropriate output voltage changes needed to vary:
Blower motor speed, flap position and the solenoids
which respond to operator selected temperature demand.
The air from two blower motors is passed through the
evaporator matrix which, depending on the positions of
the humidity buttons, removes heat from the incoming air.
Dependingon the position of the two blend flaps, the cold
air either passes directly to the vehicle outlet vents, or is
passed through the heater matrix to be reheated and then
to the vehicle outlet vents.
The amount of air passing through the heater matrix is
infinitely variable depending on ambienttemperature and
the temperature selected within the vehicle.
Selecting 'Climate Control' from the vehicle area menu,
will presentthetechnician with the dataloggertool selection

screen.

Details of the signals which may be monitored in the
system may be found in the DB7 Workshop Manual -
Section 8 - Air Conditioning'
Anti-Lock Braking Diagnostics
The Teves Mk IV Braking System consists of two sub­
systems, power braking and anti-lock braking.
The PDU software(DataLogger) only allows the monitoring
of the anti-lock braking system.
The ABS System consists of:
Four wheel speed sensors.
One control module.
Seven solenoid valves.
One pressure switch.
One fluid level switch.
The ABS System
is
controlled and continuously monitored
by the ABS control module, which automatically
switchesoffthesystemifafailure is identified, illuminating
a warning lamp and leaving
full,
boosted braking to all
wheels. A wheel speed sensor is installed at each wheel.
Their wheel speed related signals are processed by the
control module, which triggers the solenoid valves to
modulate hydraulic pressure, preventing the wheels from

locking.
The control module also monitors the fluid
level and will inhibit ABS operation should lowfluid level
be detected.
The Datalogger function will permit monitoring of the
complete system apart from the solenoid valves. The
control module transmits short duration test pulses of 25
to 100 microseconds to the solenoid valves. These
pulses are too fast for the PDU to monitor and as a result
would cause confusing waveforms.
Selecting 'Anti-Lock Braking' from the vehicle area menu,
will present the technician with the following menu of
diagnostic tools screen:
Anti-Lock Brakes Diagnostic
Datalogger
Diagnostic Trouble Codes
o
ABS Diagnostic Trouble Codes
The DTCs which are supported in the Teves Mk IV ABS
system are listed in the workshop manual - Section 5
Brakes Wheels and Tyres.
September 1996 9-43

^
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

^^?
The Aston Martin Lagonda Diagnostic System
Users Guide
The following trigger options are available:
Triggers when the signal passes above
a
specified

value,
i.e. stop lamp.
Triggers when the signal passes below
a
specified

value,
i.e. Anti-Lock brakes warning lamp.
Triggers when the signa
I
passes outside
a
specified

band,
i.e. oxygen sensor feedback.
Triggers when the signal passes into a specified

band.

Once the type of trigger has been selected the trigger
vaiue(s) (i.e. the signal level at which the trigger point wil
I

occur) should be set.
These values are set by highlighting the existing value.

i
jr:
ECT ^ 1
Trigger KBIT" ^
^^^^1

S.I.

°c
Oj
Engine coolant temperature

m
^
Highlighted Trigger Value
Press the calculator-style
icon.

A new screen should now be displayed.
Trigger Value Entry
Enter the required trigger value using the calculator-style
screen buttons.
The S.I. button enables unit selection, where applicable,
refer to S.I. Units.
Confirm the trigger value by pressing the 'tick'
icon.

The trigger screen will now be re-displayed.
Press the 'tick' icon to go back to the Parameter
Customisation screen.
Press the 'tick' icon again to return to the datalogger main

menu.

September 1996 9-59

The Aston Martin Lagonda Diagnostic System
Users Guide
ES^"^?

The screen was scrolled down until 'RRW<133' was

displayed.

The rectangle below the play icon on row 'RRW<133' was

selected.

The rectangle below the eye icon in row 'RRW<133' was

selected.

The 're-order' icon was then selected; this places
the record enabled parameters at the top of the
parameter list in numerical order.
The 'ABSWL' parameter was then selected and the trigger
switched on by touching the rectangle in the ABSWL line
below the trigger symbol.
The 'OV rectangle was then selected.
\
(n>

ABSWL
Trigger
S.I.
Anti-Lock Brakes Warning Lamp

1123;
11=3

Signals
ABSWL
RLW<133
RRW<133
BAT+P20
BAT+P3
FLS2
FRW<133
•
j^ •' S.I.
KPH
KPH
V
V

^K

KPH
i=
ABS Warning Light selection
^
Themagnifying-glasstype icon wasthen selected
to lead to the trigger customization screen.
The 'falling-edge' trigger icon was then selected.
DataLogger will then trigger from the ABSWL when the
signal passes below a specified value.
Selection of the OV trigger point
The calculator-style icon was then selected to
alter the trigger value. 11 2 31
Using the calculator-style screen buttons, a threshold
value of 6 Volts was entered.

1
7 1 1 8 1 1 9 1
Q
Q

5
1 6 1
LB m

1
^I 1 «J •
Trigger Point setting to 6V
ABSWL
Trigger
Anti-Lock Brak
^
(n>

•
1
'

^H

OV
es Warning L
.jr.
1

S.I.

°C
m
amp
J
l===-l
Falling Edge Trigger Icon
9-64 September 1996