1997 ASTON MARTIN DB7 display

^^2?
The Aston Martin Lagonda Diagnostic System
Users Guide
Airbag System Diagnostics
WARNING: Whilst it
is
completely safe to
access

and read the airbag diagnostic module memory at
the diagnostic socket, significant personal risks
exist in the performance of any other
tasks
on the
airbag system or components. Therefore all
workshop manual warnings must be read and all
safety procedures must be followed before, during
and on completion of any other practical work on
the airbag system.
System Description
The airbag system installation comprises:
Airbag Diagnostic Module
Driver and passenger airbag modules
Two front impact (crash) sensors
One 'safing' sensor
Dedicated wiring harness
SRS indicator/warning lamp
The system is designed to provide protection for both
driver and front seat passenger by automatically
deploying airbags in the event of a collision during
forward travel.
Intheeventof
a
collision, the crash and safing sensors
will operate, completing the firing circuit and causing
the airbags to inflate within 32 milliseconds. At least
one crash sensor and the safing sensor must operate to
fire the airbags.
Any faults in system components, installation or wiring
will be indicated by a flashing code on the SRS/
AIRBAG warning lamp. Fault code information may
also be monitored using the PDU or scan
tool.

A full description of the airbag system components is
included in the workshop manual.
Airbag Diagnostics
The Airbag Control Module indicates a fault by
transmitting a pulsed signal down the Airbag System
Failure line to flash the SRS/AIRBAC warning lamp.
The fault code is repeated continuously. If there are
two or more faults, the fault code with the highest
priority is transmitted first. The second fault code is
only transmitted when the first fault has been rectified.
TheSRS/AIRBAC warning lamp is also used to indicate
any problem in the seat belt pretensioner system (if
fitted). Flashing of the lamp indicates an airbag fault,
constant illumination of the lamp indicates a seat belt
pretensioner fault.
At the top left of the PDU screen there is a bullet mark
which indicates the current state of the Airbag System
Failure line. As a code is transmitted the bullet mark
can be seen to flash.The PDU reads the fault code, and
writes the code number and fault description to the

screen.
The PDU continues to monitor the transmitted

code.
If the transmitted code changes, the new code
number and description will appear below the first.
PMC Airbag
32 Drivers airbag circuit
shorted or open
o
when remedial action has been taken to correct a
fault, press the Clear Button to clear down the PDU
display. Then use the PDU to ensure that no faults are

reported.

A series of audible beeps, continuously transmitted by
the Airbag Diagnostic Module, indicates that there is
an Airbag System fault to report and that the Airbag
System Failure line
is
open circuit. The PDU is notable
to monitor the fault line in this situation as there is no
pull-up resistor, normally provided by a warning lamp
in the instrument pack.
Rapid continuous flashing of the Instrument Pack
Airbag Failure Lamp indicates that both front impact
sensors are disconnected. No fault code is reported on
the PDU, however on close inspection the bullet mark
can be seen to flicker.
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The Aston Martin Lagonda Diagnostic System
Users Guide ^=2?
Printer Use Digital Multimeter
Print Trace
The Trace Buffer is used to record technician use of the
PDU.As the diagnostics are executed, the following
information is written to trace:
Screen Title
Menu options selected
Operator questions selected
Operator actions
Control module information
Test limits and results
P codes detected by the DTC monitor
Snapshot data from the datalogger
OBD II freeze frame data
Set up the printer and load with paper. Select Print
Trace and confirm the selection. All recorded
information in the above list will be printed.
Printtrace is supported in English, French, German and

Italian.

Print Screen
The Print Screen function dumps a bitmap image of the
current screen display to the printer. This function is
particularly useful for recordingdata such as waveforms
captured by the datalogger application.
The print screen function is supported in English,

French,
German, Italian and Japanese.
Introduction
The Digital Multi-Meterprovidesthecapability to measure
voltage, current, resistance, frequency, pulse width, pulse
period and duty cycle using measurement probes or
vehicle interface adaptor channels.
WARNING: DMM measurements must not be taken
while the PDU
is
connected to the
base
station. The PDU
measurement system
becomes
referenced to earth when
connected to the base station. Serious measurement
errors may be present
because
of any voltage difference
between vehicle ground and base station earth. Operation
of the PDU in this mode has both functional and safety
implications and therefore must be
avoided.

A digital multimeter (DMM) is resident within the PDU
software toolbox.
The DMM application can be accessed from the main

menu.
On selection of "Digital Multimeter" from the main

menu,
the PDU will always display the same screen,
known as the DMM general screen.
DDD
DMM : Voltage
(+) : RED PROBE
(-) : BLACK PROBE
HOLD/UPDATE Exit
The DMM General Screen
The DMM is used to display measured values, to three
significant figures, in the correct units.
Modes of measurement are Voltage, Voltage (AC),
Resistance, Frequency, Pulse Period, Pulse Width (High/
Low) and Duty Cycle. Current measurements up to 50A
may be made using the current probe. Measurements are
usually madedirectlyusingthe PDU measurement probes.
On the air conditioning system only, when using the VIA,
measurements may be made between specific module

pins.
If required, this mode must be specified when
specifying the measurement to be made.
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The Aston Martin Lagonda Diagnostic System
Users Guide
Operation
On selection of DMM the general screen, as shown in Fig.

1,
will be displayed.
Voltage is the default selection for measurement, with red
and black probes selected
as
sources.
To choose alternatives
to these options, press the relevant description for change
followed by the 'tick' icon in the top, right-hand, corner.
If the measurement mode (Voltage) is selected for change,
followed by a confirming 'tick', a screen as show will be

displayed.

Select DMM Measurement
^Q^||[
Resistance
Pulse Period
Pulse Width
(low)
Voltage (AC)
Frequency
Pulse Width
(High)
Duty Cycle
DMM Measurement Selection
Selection of any option from this screen, followed by a
confirming 'tick', will return the operator to the general
screen but with the new mode displayed against DMM.
If 'Resistance' is selected an additional
icon,
showing an
audio symbol, will appear above the "EXIT" display. This
icon allows the enabling / disabling of an audible signal
which sounds when measured valuefal
Is
below 0.5 ohms.
Touch the icon to toggle the warning ON / OFF directly,
no confirming 'tick' is necessary. A 'cross' is displayed
over the icon when warning is turned OFF.
Measurement Source Selection
If
a
measurement source (either RED or BLACK PROBE) is

selected,
a screen as shown will be displayed. This screen
may vary depending upon the various probes which can
be connected to the PDU.Afull list of possiblesources will
be displayed on the 'Source Select' screen.
Select (-) Channel
BLACK Probe
Battery positive
Battery negative
Module pin
Selection of (+) and (-) measurement channels
Selection of any source option, except "Module Pin", will
return the user to the general screen, which will display
the revised source.
Module Pin Selection (Air-Con only)
Selection of "Module Pin" will display a screen as shown.
Selection of one of the options displayed on this screen
allows the operator to make measurements on designated
pins of the air conditioning control module. When the air
conditioning module is selected PDU will display a wiring
connection diagram, as shown.
Cable Setup
Module Connection
September 1996 9-51

The Aston Martin Lagonda Diagnostic System
Users Guide [S:S3^2?
The PDU will then check the cable connections. Until all
connections are correct, the PDU will not allow progression
beyond this
screen.
Pressingthe'asterisk'icon and selecting
abort returns the operator to the general screen if an
incorrect system has been chosen.
If selection and wiring are correct a numeric keypad will
be displayed. The operator can nowenterapin numberto
be tested, using this keypad.
Pin
Numeric Keypad
Display Freezing
To assist the operator a "HOLD/UPDATE" option is
displayed on the general screen. This option is selected as
default on the general screen and allows a reading to be

'frozen'
on screen when the 'tick' icon is pressed. A 'tick'
button is also incorporated into the red probe so that a
remote 'freeze' command can be sent to PDU, holding the
reading until the operator can view the screen. A frozen
value is displayed on a 'grey' background indicating that
the value is on HOLD. Re-pressing the 'tick' icon (either
local or remote) unfreezes the display and restores the
normal display background.

b.nn

DMM
(-)
(-)
Voltage
RED PROBE
BLACK PROBE
HOLD/UPDATE
The "HOLD/UPDATE" option operates on one touch of
the 'tick' icon (or 'tick' button) irrespective of the state of
the screen backlight. Therefore it is not necessary to
reinstate the screen backlight if there has been no operator
contact with the PDU for five minutes (or longer). Pressing
"HOLD/UPDATE" reinstates the backlight and initiates/
releases display 'freeze' automatically.
System Exit
At any point during DMM operation it is possible to exit
the system by either pressing the 'asterisk' icon and
selecting abort, or pressing "EXIT" (where available)
followed by a confirming 'tick'.
The Hold/Update option
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^7
The Aston Martin Lagonda Diagnostic System
Users Guide
Diagnostic Trouble Codes
Introduction
The 'Diagnostic trouble codes' application enables the
PDU to monitor the trouble codes logged in selected
control module's and provides the following functions:
• Decode and display any trouble codes logged by
the control module(s) being monitored.
• Decode and display enhanced diagnostic
information, together with any count of the number
of occurrences, when supported by the control
module(s).
• Clearsomeorallofallthesetroublecodes selected
by the user on the PDU screen, when supported by
the control module(s).
Diagnostic Trouble Codes are logged by the Engine
Management and by the Automatic Transmission control
units and can be accessed using the PDU. Logged codes
in the 95 MY Teves Mk II ABS controller can only be
accessed using the brake warning light. The Air
Conditioning control unit does not log trouble codes.
Operation
From the Main Menu make the following selections:
Select Diagnostics
Select Engine or Transmission
The system will then load the appropriate
software
Select Diagnostic Trouble Codes
Connect the PDU to the car as shown on the
screen diagram
Select the / icon to confirm connection
The PDU will then interrogate the chosen control
unit and will display any logged trouble codes.
If no trouble codes have been flagged by the control
module, the PDU will display a screen similar to Fig. 15
The trouble code screen will be headed by a module title
block followed by a list showing all logged trouble codes
for the seleaed module.
Note: There may be more logged diagnostic trouble
codes than displayed on the first
screen.
Use the 'up
arrow' and 'down arrow' icons if
necessary
to scroll
through the total display.
On the Zytek engine management system only, each
trouble code definition will be individually selectable to
invoke the clear trouble codes screen. If one or more
trouble codes are selected, the clear all and clear selected
trouble code icons will be displayed.
On all other systems, only the 'Clear All' function is
available.
'Clear All' and 'Clear Selected Codes' Icons
Freeze Frame Data
m*
As any engine management trouble code is

logged,
the system takes a snapshot (freeze
frame) and records the state of all signals at
that time.
On the Zytek engine management system (95 MY), freeze
frame data can be displayed by selecting a logged trouble
code and touching the 'snowflake'
icon.

On the 97 MY EEC V engine management system, freeze
frame data is accessed using the OBD II scan
tool.

ECC-V EMS DTC'S
No fault codes present
l^
D
a
El
The No Fault Codes screen
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The Aston Martin Lagonda Diagnostic System
Users Guide
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Clear all Trouble Codes
Selecting the clear all trouble codes icon will invoke a
confirmation window.
EEC-V EMS
dri
dri
CONFIRM
Clear all logged trouble
codes?
O

'Clear
All Codes' confirmation
screen

Selectingthe'tick'will instructthePDU to clear all logged
trouble codes in the selected module
and
return to the no
logged codes screen.
Select the 'tick' icon to exit Diagnostic Trouble Codes.
Clear Selected Trouble Codes
(95 MY Zytek Engine Management Only))
If
you
wish only to clear selected codes on the Zytek ECU
and
leave others
for later
investigation,
proceed
as
follows:
Highlight only the trouble code(s) to be cleared.
ZYTEK EMS
1 : Idle speed control valve driver #1
5 : Purge Valve driver #1
12 : Cooling fan#l relay driver
14 : Lannda heater
#2
driver
1 : Idle speed control valve driver #1
Highlighting
Selected
Trouble
Codes

Select the 'clear selected trouble codes'
icon;
this will
invoke a confirmation window.
Selectingthe 'tick' icon will instruct
the
PDU to clear only
the selected trouble codes from the control module fault

table,
and if successful, the system will return to the
'Diagnostic trouble codes' screen.
If any attempt to clear trouble codes is unsuccessful, a
warning window will be displayed.
This will indicatethat
some selected
trouble codes remain
logged,selectingthe'tick'iconwillreturntothe'Diagnostic
trouble codes' screen.
Select the 'tick' icon again to exit Diagnostic Trouble
Codes.
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"^I?
The Aston Martin Lagonda Diagnostic System
Users Guide
Datalogger
Introduction
Datalogger is software produced to identify permanent or
intermittent faults on vehicle electronics. The objective of
Datalogger is to provide a view of the vehicle's electrical
behaviour, such that intermittent activity can be recorded
and interpreted quickly and accurately. Running on the
Portable Diagnostic Unit (PDU), the Datalogger
appi ication can captu
re
vehicle information in three ways.
• Serial communications direct from the control unit.
• Parallel communications using the Interface Adaptor.
• Direct signal monitoringusingthemeasurementprobes.
Serial Communication
Serial Communication is a two-wire communication link
between the PDU and most vehicle control modules
providingdigital measurements forconnected components.
The serial communication link allows the tester to
determine the current condition of components connected
to the control module, and to identify any history of faults.
On later vehicles, the PDU is connected to the vehicle
diagnostic sockets via the mu
Iti
Protocol Adaptor (MPA) to
gather serial data from the control modules.
Parallel Communication
The Vehicle Interface Adapter (VIA) provides an interface
between the PDU and the vehicle harnesses for the
acquisition of multiple analogue measurements. The VIA

is
connected between the relevantvehicle control module
and it'sharness connector. Thisallows the PDU to captu re
information from a multitude of channels entering the
control module. This vehicle interface is used with control
modules not equipped with a serial communication link
(Teves Mk II braking system and the air conditioning
system).
Measurement Probes
The measurement probes permit readings to be taken
directly from any connector on the vehicle.
Datalogger Applications
Datalogger may be used to interrogate the following DB7
systems:
• ABS braking system controller
• Engine Management Controller
• Air Conditioning Controller
• Automatic Transmission Controller
• Passive Anti Theft (97 MY)
• Security System (97 MY)
Using the Datalogger
Configure the vehicle to the normal operating conditions
for the system under test.
From the PDU main menu screen:
Highlight 'Diagnostics'.
Press the 'tick' icon to confirm the selection.
Enter the Transmission Type and confirm the selection.
Select the Vehicle Area to be tested and confirm the

selection.

The PDU tools screen should now be displayed.
Highlight 'Datalogger'.
Confirm the selection with the 'tick'
icon.

The PDU connection screen should now be displayed.
Cable Setup
Upper Diagnostic Socl o
PD\J Connections for Datalogger
Connect the PDU to the vehicle as described in the screen

image.

Switch On the ignition and press the 'tick'
icon.

September 1996 9-55

The Aston Martin Lagonda Diagnostic System
Users Guide •^^
'Establishing connection to control module' should now
be displayed on the screen.
If for any reason the PDU cannot communicate with the
relevantvehiclecontrol modulea 'communicationsfailure

screen'
will be displayed with a retry option.
Check all connections before retrying.
Once commu nications are successfu
I
'Starti ng Datalogger'
will appear on the screen momentarily.
Datalogger will automatically default to the waveform

screen.

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Datalogger Waveform Screen
•
Thedefaultwaveform screen will display previous
selected parameters. Ifthese parameters are ideal
for the test procedure then Datalogger can be
started immediately, simply by pressing the record
icon.

Select the main menu icon to go to the main
menu screen.
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Main Menu
The datalogger main menu) is the main control screen,
and can be selected from any of Datalogger's screens.
The main menu provides a single touch entry to each of
Datalogger's features.
These features include (left to right, top to bottom):
Bargraph Display
Parameter Customisation
On-Road Manual Trigger
Waveform Display
Datalogger timing
Parameter Customisation
Parameter customisation enables the selection of signals
to be recorded by Datalogger. It also enables the signal
units to be selected, the order in which the signals are

displayed,
and whether the displayed signals are to be
used as a trigger.
The Parameter Customisation screen presents selections
in a five column table. Each column from left to right
represents:
Parameter name or acronym.
Record enabled.
Display order.
Trigger action.
Display S.I. Units.
Signals •
CO?
J^ •' S.I.
BAT-
ECT
EGRS
ETCC
ETCS
FF11
FF12
/•? 103
Parameter Customisation
Datalogger Main Menu
9-56 September 1996