1997 ASTON MARTIN DB7 battery

^=2?
The Aston Martin Lagonda Diagnostic System
Users Guide
Software
Software for the PDU system is supplied on CD ROM
discs and supports diagnosis on the following control

units:

Zytek Engine Management System (95 MY)
EEC-V Engine Management System (97 MY)
CM 4L80-E Transmission Controller
PATS - Passive Anti Theft System
Teves Mk II ABS System (95 MY)
Teves Mk IV ABS System (97 MY)
Valeo Air Conditioning System
PMC Airbag System
Megamoss Security System
Autoliv Drivers Seat Belt Pretensioner
(where fitted)
All of these systems are supported in English, French,

Italian,
German and Japanese.
In addition to the specific system software listed above,
thePDU isalsoequipped with general purpose software
to provides multimeter, printing and PDU training
options.
Software for 95 and 97 Model Year Vehicles
Software for both the 95 and 97 model year vehicles is

provided.

The PDU system requires a Vehicle Interface Adaptor
(VIA) to communicate with the control units of 95
model year vehicles.
Communication with 97 model year control units is
principally via an Aston Martin multi-protocol adaptor
to 2 inbuilt diagnostic sockets in the vehicle. Only the
air conditioning unit requires the VIA on 97 model year
vehicles.
If the multimeter function is used, the Vehicle Battery
Adaptor (VBA) will be required to provide the basic
supply and ground levels for the multimeter.
Software Loading and Selection
Ensure that the system is powered up and that the PDU is
correctly connected to the base station. Check and if
necessary load the DB7 software CD Revision 002. (see
the installation guide)
Switch 'on' the PDU which will run through two front
screens and then load the following initial PDU software.
Operating System
Main Menu
Selector
Digital Multimeter
Interactive Training
September 1996 9-29

The Aston Martin Lagonda Diagnostic System
Users Guide ffi:S5'=2?
Engine Datalogger
The datalogger software is designed to aid the technician in identifying permanent or intermittent faults in the DB7's
electrical and electronic systems. It can provide a recorded view of selected signals over a chosen time period. This
recording may be captured in a static, rolling road or road test situation. Data recorded during such tests may then be
analysed on completion of the test or printed out for later analysis.
Datalogger operation is described using a fully worked example at the end of this PDU Users Guide.
The full list of datalogger signal names and descriptions is provided in the DB7 OBDII Diagnostic Manual and on the PDU

screen.
The following list is a summary of the PCM signals which may be monitored.
Signal Description
ACCS Air-Con Control Switch - 1 = A/C On
ACP Air-Con Pressure Sensor - 1 = A/C pressure high
ACT MAX Maximum Intake Air Temperature signal during normal running
Adap Fuel 1 Current Adaptive Fuel Correction - (% of range)
Adap Fuel 2 Current Adaptive Fuel Correction - (% of range)
ADPT1F Adaptive Fuel - Table 1 failure mode
ADPT2F Adaptive Fuel - Table 2 failure mode
AIR Air Pump On/Off - 1 = Pump On
AIRM Air Pump Monitor -1 =
high,
pump on
B+ Battery Positive - Volts
BARO Barometric Pressure
CID Cylinder Identification - Cam sensor status
CMP STAT Cam Position Sensor -1 = CID mis, not currently reliable
DRVCNT Number of OBDll Drive Cycles Completed
DSDRPM Desired engine speed (RPM)
DTCCNT Diagnostic Trouiale Codes Count (Fault codes + pending codes. MIL and non-MIL)
ECT MAX Maximum Engine Coolant Temperature signal during normal running
ECT STAT Engine Coolant Temperature - in or out of range
ECT-C Engine Coolant Temperature - "C or raw counts
ECT-V Engine Coolant Temperature - Volts or raw counts
EGR STAT EVP EGR sensor failure
ENGLOAD Engine Load (Ratio of air charge over standard)
ENGRPM Engine Speed - RPM
EPT DPFE Sensor feedback
EVAP DC Cannister Purge Duty Cycle (% on)
EVAPCVA Vapour Management Valve (VMV) fault detected
Evts HI Cumulative cylinder events total carried over from previous background logic executions
Evts LO Cumulative cylinder events total carried over from previous background logic executions
FPM Fuel Pump Monitor - 0 = pump off, 1 = pump on
FPUMP DC Desired Fuel Pump Duty Cycle - 0% or 100%
H02S12 Sensor Output - Volts
H02S21 Sensor Output - Volts
H02S22 Sensor Output - Volts
H02S1I Sensor Output - Volts
HFC High Speed Fan Status
Htrl
1
ret Highest number of retries seen on the H02S 11 heater
Htrl 2 ret Highest number of retries seen on the H02S 12 heater
Htr21 ret Highest number of retries seen on the H02S 21 heater
Htr22 ret Highest number of retries seen on the H02S 22 heater
HTRCM11 H02S n heater current
HTRCM12 H02S 12 heater current
HTRCM21 H02S 21 heater current
HTRCM22 H02S 22 heater current
9-36 September 1996

The Aston Martin Lagonda Diagnostic System //~~^ ^?~?^ " ^ ^
Users Guide
Airbag Diagnostic Trouble Code Monitor
The following diagnostic trouble codes are supported by the Airbag Control Module:
12 Low battery voltage
13 Air bag circuit shorted to ground
14 Front inpact sensor circuit shorted to ground
21 Safing impact sensor incorrectly mounter to vehicle
22 Safing impact sensor output shorted to battery voltage
23 Safing impact sensor input feed / return open circuit
24 Safing impact sensor output feed / return open circuit
32 Driver side airbag circuit high resistance or open
33 Passenger side airbag circuit high resistance or open
34 Driver side airbag circuit low resistance or short circuit
41 Front right impact sensor feed / return open circuit
42 Front left impact sensor feed / return open circuit
44 Front right impact sensor incorrectly mounted to vehicle
45 Front left impact sensor incorrectly mounted to vehicle
51 Airbag CM internal thermal fuse - intermittent short to ground
52 Back up power supply - voltage boost fault
53 Front impact sensor circuits resistance to ground or internal Airbag CM failure
9-46 September 1996

^^?
The Aston Martin Lagonda Diagnostic System
Users Guide
Seat Belt Pretensioner Diagnostics
(where fitted)
Description
The DB7 seat belt pretensioner system operates the
drivers seat belt pretensioner in conjunction with the
Airbag system. The seat belt pretensioner control
module is located underthe right hand seat, beside the
seat control module.
The pretensioner control module calculates changes
in vehicle speed using an input signal from an
accelerometer. When a collision is detected (Rapid
reduction in vehicle speed) the pretensioner charge is
fired using electrical energy stored in a capacitor
within the pretensioner control module. Firing of the
pretensioner charge applies additional tension to the
drivers seat belt.
The airbag and seat belt pretensioner systems share the
SRS (Airbag) warning lamp. Any fault detected by the
pretensioner control module is indicated by constant
illumination ofthe
SRS
(Airbag) warning
lamp.
Flashing
of the SRS warning lamp indicates a fault in the airbag

system.

Should both systems develop faults, the pretensioner
system will permanently illuminate the warning lamp.
This would mask the airbag system warning indication.
Therefore, rectify the pretensioner fault and then retest
for faults in the airbag system
The pretensioner control module can log up to 10
diagnostic trouble codes together with a time since
each fault was alerted to the driver. Each fault will be
identified as 'Permanent' or 'Intermittent' on the PDU
diagnostic trouble codes screen.
System Connections
The Autoliv RC5 Pretensioner Control Module has an
18 pin connector featuring six shorting bridges. The
mating halves ofthe connector may be securely locked
using a double mechanical locking system.
The following pins on the control module connector
are used in the Aston Martin seat belt pretensioner

system:

Pin 1
Pin 2
Pin n
Pin 12
Pin 14
Pin 15
Case
September 1996
Ground
SRS/Airbag Warning Lamp
Drivers airbag positive
Drivers airbag negative
Serial communications
12 volt positive feed
Ground
System Fault Strategy
No single fault may cause an unexpected deployment.
The controller will supervise the airbag/pretensioner
electrical system in order to warn the driver should a
fault occur. Any fault detected by the self diagnostics
shall cause the airbag warning lamp to be activated,
and in some cases the pretensioner control module to
enter shutdown mode. In shutdown mode, the energy
ofthe reserve capacitors shall be discharged to avoid
unintended deployment.
As the ignition is switched on, the pretensioner
controller will directly discharge theenergy capacitors.
When the start up procedure is completed without
detecting any faults, the converter will be activated
allowing the capacitors to be
charged.
The system shall
be fully active within 11 seconds after switching the
ignition on providing that no faults are detected.
All system faults monitored by the controller are filtered
in software to avoid fault warnings due to transient
electrical disturbances.
If a fault which could lead to inadvertent deployment
bedetectedbythemicroprocessor,asoftwareshutdown
will be generated. However, a leakage to an earth or
positive potential in the pretensioner output circuit
shall not cause the controller to enter shutdown mode.
If
a
permanent short of the ignition transistor occurs, a
shutdown shall be generated by the hardware circuit.
If a shutdown occurs, the system shall be unable to
deploy the pretensioner after a period of
3
seconds (i.e.
capacitors discharged to under minimum deployment
voltage).
WARNING: To avoid the possibility of personal
injury caused by accidental deployment of the
pretensioner, disconnect the vehicle battery and
wait at least 10 minutes for all voltages to fully
discharge before working on the pretensioner
system. This covers the possibility of the normal
capacitor discharge circuits being inopera tive and
failing to discharge the capacitor when instructed
to do so.
If the module enters shutdown mode, all diagnostic
functions are stopped, but the communications link
remains active. A fault code corresponding to the
cause of the problem may be read by the PDU.
9-47

The Aston Martin Lagonda Diagnostic System
Users Guide ^?
Seatbelt Pretensioner Diagnostic Trouble Codes
050A Pretensioner squib leak to battery positive
050B Pretensioner squib leak to ground
050C Pretensioner squib high resistance
050D Pretensioner squib low resistance
0D13 Capacitor voltage error
0D14 Capacitor capacitance
0D09 Energy reserve switch
0D1E Energy shutdown switch
050E Seatbelt pretensioner switch error
0109 Accelerometer function
01OA Acceleration out of range

01
OB Accelerometer offset
0209 Safing sensor error
030A Temperature sensor error
060C Warning lamp short circuit
060D Warning lamp open circuit
060E Warning lamp driver error
OAOC Analogue voltage error
0A09 Communications error
090A EEPROM not programmed
0909 EEPROM checksum
OAOA External watchdog error
OAOB External watchdog time out
020A Safing sensor not closed
090C RAM check error
9-48 September 1996

^^?
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 ^2?
Split Cursor Icon
The split cursor icon spl its the vertical cursor into
two parts.
1^

VV

One permanent static cursor represented by
a
solid vertical
line in the waveform display, and one moveable cursor
represented by a dotted vertical line, this is moved by
applying finger pressure to the screen in the position the
cursor is required.
The digital display of the waveforms will now represent
the difference in levels between the two cursors and not
the absolute signal level as detailed earlier.
Re-scale Vertical Icon
Normally all of the waveforms are displayed
with the vertical axis representing the maximum
possible variation ofthesignal,
e.g.
battery voltage
0 to 16 V.
The re-scale icon causes the waveform to scale such that
the recorded variation determines the scale, this normally
enlarges the vertical scale.
The scaling operation can be performed on any of the
displayed waveforms by highlighting the parameter name
prior to the operation.
Once auto-scaling
has
taken place, further manual scaling
may be achieved by using the '+' and '-' system icons.
Waveform Display Number
This icon enables control of the number of
waveforms displayed on the screen at any one
MMV
MMV
time.

Pressing this icon causes the '+' and '-' system icons to
appear. Using these system icons increase or decrease the
number of displayed waveforms.
It should be noted that the more waveforms displayed the
poorer the detail becomes, therefore the number of
displayed waveforms should be kept to a minimum.
Horizontal Scale
-^ This icon performs the same function as the re-
scale vertical icon only for the horizontal axis.
By expanding the scale more detail will be available, thus
proving easier to analyse. However the amount of time
displayed on any one screen will be reduced.
Bargraph / Digital display
Bargraph / Digital display provides another format in
which to display recorded date.
The Datalogger icons operate similar to those used in the
waveform display. However one new icon is provided as
a toggle option from bargraph to digital display.
OV
TP :3.91V
ECT: 57°C 5V
-49°C lAT: 0°C 150°C
-49°C 150°C
II 88 zF 1^
Bargraph / Digital Display
On-Road Trigger
When on-road trigger is selected using the motorway icon
from the main menu a symbol is displayed over the entire
screen display area.
This option is intended for use during on-road tests to
ensure that the PDU screen does not distract the driver.
Press the record icon to start capturing data, a trigger icon
will replace the record
icon.

• iF •
Datalogger Trigger Icon
Press the trigger icon to instigate the manual trigger.
Once the trigger procedure has occurred, a stop icon will
replace the trigger
icon.
Press the stop icon to stop
capturing data.
9-62 September 1996