Instrument ASTON MARTIN DB7 1997 Owner's Manual

' -^ ^ The Aston Martin Lagonda Diagnostic System
Installation Instructions
Service Centres
UK and EIRE
GenRad Limited, Horsefield Way, Bredbury Industrial Park, Bredbury, Stockport, Cheshire SK6 2SU, England
Telephone: 061-406-8209 Fax: 061-406-8480
Germany
GenRad GmbH, Neumarkter Strasse 83, 81673 Munchen, Germany
Telephone: 01049-89-431990 Fax: 01049-89-43199101
Switzerland and Austria
GenRad AG, Drahzug Strasse 18, Postfach 8032, Zurich, Switzerland
Telephone: 010411-422-2420 Fax: 010411-422-2065
Italy
GenRad SPA, Via Fantoli 21/13, 20138 Milano, Italy
Telephone: 01039-2-502951 Fax: 01039-2-5063331
France, Spain and Portugal
GenRad Europe Paris, Succursale de GenRad Europe Limited, 6 Rue Vincent Van Gogh, 93364, Neuilly Plaisance
Cedex, France.
Telephone: 01033-1-49442200 Fax: 01033-1-49442298

Sweden,
Norway, Denmark and Finland
Lagercrantz Kontest AB, Kung Hans vag 3, Box 986, 191 29 Sollentuna, Sweden
Telephone: 01046-8-626-06-20 Fax: 01046-8-754-88-67
Netherlands, Belgium and Luxembourg
Multidata BV, Postbus 137, Bedrijvencentrum "De Baanderije", ParallelwegZuid 33/1,5280 AC Boztel, Netherlands
Telephone: 01031-4116-83775 Fax: 01031-4116-85359
USA and Canada
GenRad Inc, 300 Baker Avenue, Concord, Massachusetts,
1
742, USA.
Telephone: 0101-508-369-4400 Fax: 0101-508-287-2011
Singapore, Taiwan, Hong Kong and Thailand
GenRad Inc, 73 Science Park Drive, Cintech Building #03-04, Singapore, Singapore 0511.
Telephone: 01065-2784400 Fax: 01065-7766422
Australia and New Zealand
Nilsen Instruments, 25-27 Paul Street North, North Ryde, New South Wales 2113, Australia.
Telephone: 01061-2-7362888 Fax: 01061-2-7363005
Japan
Tokyo Electron Limited, 2-30-7 Sumiyoshi-Cho, Fuchu City, Tokyo, Japan 183
Telephone: 01081-423-33-8377 Fax: 01081-423-33-8489
May 1996 9-21

^^
The Aston Martin Lagonda Diagnostic System
Installation Instructions
Statement of Calibration
Product Range Aston Martin Diagnostic System
Product Type Portable Diagnostic Unit
Product Number 3130-001 7
We certify that the above product has been tested and found to conform to the product specification, priorto dispatch
from GenRad. The measurements performed by this equipment are traceable to international measurement
standards. Calibration records, including the date of calibration and the serial numbers of the measurement
instruments are maintained by GenRad and are traceable through the PDU System serial number.

NOTE:
The PDU will not require any periodic adjustment in order to maintain specified measurement accuracy.
Calibration Measurements
Ambient temperature during calibration 20±1 °C.
The test resistances in the table below are applied between the red and black probes. The PDU is set to measure
resistance between these probes using the DMM function. The PDU reading must be between the limits shown.
Test Resistance
10Q
10MQ
PDU Reading Limits
9.84f2-10.16Q
8.22MQ -11.78MQ
The test voltages in the table below are applied between the red and black probes. The PDU is set to measure voltage
between these probes using the DMM function. The PDU reading must be between the limits shown.
Voltage
50mV
lOOmV
160mV
350mV
720mV
1.45V
2.90V
7.25V
14.5V
29V
49V
98V
175V
PDU Reading Limits
48mV - 52mV
98mV - 102mV
157mV -163mV
345mV-355mV
712mV-728mV
1.43V - 1.47V
2.86V-2.94V
7.1 7V - 7.33V
14.35V- 14.65V
28.7V-29.3V
48.5V-49.5V
97.0V-99.0V
173.7V-176.3V
May 1996 9-25

^^?
The Aston Martin Lagonda Diagnostic System
Users Guide
Transmission Diagnostics
Selecting 'Transmission from the vehicle area menu will
present the technician with the following transmission
diagnostic tools menu:
Transmission Diagnostic
• Datalogger
• Diagnostic Trouble Codes
o
The Datalogger function is fully described in the worked
example at the rear of this PDU Users Guide.
Transmission Datalogger
The PDU datalogger function may be used to monitor the
following transmission controller signals
DIGS Number of DTCs Logged
The Diagnostics status manager (DSM) receives and
processes fault information and decides when a DTC
should be logged and the MIL turned on (if enabled). The
actual total stored is indicated by the parameter DTCS.
FBRAKE Brake Switch
The footbrake switch signal is input to the
TCM.
The input
is normally at ground potential and goes open circuit
when the brakes are applied. If the torque converter
clutch is applied it will disengage when this signal is

detected.

FMA Actual Force Motor Current
The force motor regulates the transmission fluid pressure.
It is a variable force solenoid whose coil current is
determined by the TCM. Range 0 -1.245 amps. A driver
circuit limits excessive current flow and performs a
ratiometric comparison of Desired (commanded) Force
Motor Current and Actual Force Motor current. The
parameter monitors the Actual Force Motor current 1 Bit
= l/204.8amps.
HOT Hot Mode
The signal from the transmission temperature sensor is
used to control TCC and line pressure. It is also used in
many diagnostic signals and is a critical component for
OBD II. Above 120°C the TCC is on in 2nd, 3rd and 4th

gears.
This reduces transmission temperature by decreasing
the heat generated by the torque converter. It also
provides maximum cooling by routing transmission fluid
directly to the transmission cooler in the radiator. When
the Hot Mode is ON the bit is set to 1.
IGN+ Ignition Feed Positive
The TCM receives ignition voltage through TCM pin 53.
MD Desired Force Motor Current
The force motor regulates the transmission fluid pressure.
It is a variable force solenoid whose coil current is
determined by the TCM. Range 0 -1.245 amps. A driver
circuit limits excessive current flow and performs a
ratiometric comparison of Desired (commanded) Force
Motor Current. The parameter mon itors the Desired Force
Motor current 1 Bit = 1/204.8amps.
RATIO Actual Gear Ratio
The diagnostic detects malfunction in the transmission
output components by monitoring the actual gear ratio.
The actual gear ratio is calculated using input (Ni) and
output speed (No): Ratio = Ni/No. This is compared with
the standard gear ratio for each gear. Malfunction can be
defined as: actual gear ratio is not equal to any of the
standard gear ratios.
RPM Engine Speed
The engine speed signal is input from the instrument pack.
The
signal
origi
nates
at the crankshaft
sensor.
The crankshaft
sensor signal is modified by the PCM and the instrument
pack before being input to the TCM.
SSA Shift Solenoid A
Shift solenoid A is attached to the valve body and its outlet
is open to exhaust when it is switched off. A OFF - outlet
open - 2nd and 3rd gears selected. The solenoid is
energised by the TCM providing an internal ground to
close the outlet. A ON - outlet closed -1 st and 4th gears

selected.

SSB Shift Solenoid B
Shift solenoid B is attached to the valve body and its outlet
is open to exhaust when it is switched off. B OFF - outlet
open - 1st and 2nd gears selected. The solenoid is
energised by the TCM providing an internal ground to
close the outlet. B ON - outlet closed - 3rd and 4th gears

selected.

September 1996 9-41

^^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.
September 1996 9-45

The Aston Martin Lagonda Diagnostic System
Users Guide 5^^?
Only the data within the selected time period will be

stored.
A trigger is used to define the zero time point on
any waveform display. This is used to make it easier to
locate the actual point at which the fault occurred on the
waveform display. Triggers may take three forms.

1.
Manual Trigger
A manual trigger would be used in circumstances where
the technician can clearly identify the point when the fault
occurs and has access to the PDU at this point.
The trigger icon should be pressed on the waveform /
bargraph display (ortheon-road trigger icon) at the instant
the fault occurs. This will then become the zero point for
the waveform/bargraph display. The waveform/bargraph
display up to this point would have a negative form.

2.
Fault Code Trigger
The fault code trigger is used when the first indication of
a fault is normally by the appearance of a warning lamp
within the instrument pack. For some vehicle systems
Datalogger can trigger on specific fault codes, this type of
triggering is more precise than simply triggering on the
warning lamp.
This trigger
is
selected during the parameter customisation
process. To select a fault code to trigger 'on', set the fault
code (parameter) to record.
Asign the display order by touching the rectangle below
the Eye icon repeatedly until the desired display order
number is shown.
Press the rectangle in the trigger column.
Highlight the fault code parameter again and select the
magnifying glass
icon.
The trigger customisation screen
will be displayed.
Select the appropriate trigger style icon and select the tick
icon to confirm.
Press the Tick icon again to return to the main Datalogger

screen.

Select the Record icon to start data capture.
The unit will trigger when the fault code appears and will
set the zero time point of the waveform / bargraph display.
3. Specific Signal Trigger
It is possible to select a specific parameter or signal to
trigger Datalogger.
Triggering on specific signals is likely to be used when the
vehicle system has no on-board diagnostics or when
diagnostic information is not readily available at the time
the fault occurs, e.g. air-conditioning.
Thistypeoftriggershouldonly be used when it is known
that a particular signal has certain characteristics at the
time the fault occurs, e.g. one signal will always go from
12 Volts to ground, bringing on a warning lamp when a
particular fault occurs,
as
this is a known event, this signal
may be used to trigger the PDU.
Trigger Selection
Any of the record enabled parameters may be used to
trigger Datalogger.
To select a trigger highlight the parameter name, a
magnifying glass type icon will appear at the bottom of the

screen.

Select the magnifying glass type
icon.

The trigger action screen should be displayed.
ABSWl
Trigger

-T-

Anti-lock Brak
^ J^HL
^M

ov

es Warning
L

zF
!
=^

S.I.

°C
Ei
.amp
i
m,
Trigger Action Screen
9-58 September 1996