1997 ASTON MARTIN DB7 ABS

^?
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
Em^'^?

ABS Datalogger
The following signals in the Teves Mk IV ABS system may
be monitored using the datalogger function.
DTCs Number of DTCs Logged
The Diagnostic status manager (DSM) receives and
processes fault information and decides when a DTC
should be logged and the MIL turned on. The actual total
stored is indicated by the parameter.
FBRAKE Brake Switch
The signal from the brake switch is used by the CM to
ensure that traction control is inhibited when the brakes
are applied. The input circuitry within the CM is a
1
OK
pull-up to ignition voltage. When the switch is closed the
parameter is set to 1.
FLWS Front Left Wheel Speed Sensor
An indication sensor outputs a sinusoidal wave form 48
pulses per revolution. The output is processed by the CM
to control braking and traction. The sensor is continually
monitored for open and short failure and operating range.
If its output exceeds 330km/h it is deemed to be faulty and
the CM is disabled. The parameter tracks the sensor
weaveform through 255 steps.
FRWS Front Right Wheel Speed Sensor
An indication sensor outputs a sinusoidal wave form 48
pulses per revolution. The output is processed by the CM
to control braking and traction. The sensor is continually
monitored for open and short failure and operating range.
If its output exceeds 330km/h it
is
deemed to be faulty and
the CM is disabled. The parameter tracks the sensor
weaveform through 255 steps.
RLWS Rear Left Wheel Speed Sensor
An indication sensor outputs a sinusoidal wave form 48
pulses per revolution. The output is processed by the CM
to control braking and traction. The sensor is continually
monitored for open and short failure and operating range.
If its output exceeds 330km/h it
is
deemed to be faulty and
the CM is disabled. The parameter tracks the sensor
weaveform through 255 steps.
RRWS Rear Right Wheel Speed Sensor
An indication sensor outputs a sinusoidal wave form 48
pulses per revolution. The output is processed by the CM
to control braking and traction. The sensor is continually
monitored for open and short failure and operating range.
If its output exceeds 330km/h it is deemed to be faulty and
the CM is disabled. The parameter tracks the sensor
waveform through 255 steps.
Passive Anti Theft (PATS) Diagnostics
Security System Diagnostics
Becauseof the requirementto maintain vehicle security,
the PATS and Security System operating instructions
and diagnostics are covered in the Vehicle Security
supplement to section 6 of the workshop manual. This
supplement has restricted circulation and is only
available to Aston Martin Dealers.
9-44 September 1996

^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
September 1996 9-53

"^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 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

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

^?
The Aston Martin Lagonda Diagnostic System
Users Guide
Datalogger Example
A customer reported intermittent illumination of the
anti-

Lock Brakes (ABS) warning lamp.
TheABScontrolmodulewas interrogated, producing fault
code 33 (95 MY), right-rear wheel speed sensor.
The PDU was used to check the wheel speed sensor
output using the ABS warning lamp as a trigger.
The PDU was setup to the vehicle's configurations and
Datalogger was accessed.
Datalogger automatically defaulted to the waveform

screen.

30V
MPROBE
OV
240KPH •
FLW<133
OKPH .
240KPH •
FRW<133
OKPH .
OS 95s 190s
^ ^ R • i=3
Datalogger Waveform Screen
The main menu icon was selected to access the main
menu screen.
The main menu screen is the main control screen for
access to Datalogger's subsystems.
^/^
The customisation icon was selected, and the
selection was confirmed using the 'tick'
icon.

The parameter customisation screen was then displayed.
Signals • c05 d^ CZf S.I.
ABSWL
BAT+P20
BAT+P3
FLS2
FLW<133
FLW>133
FRW<133
•
•
•
•
7
6

2||

3
V
V
V
1 2 3 W c
V
KPH
KPH
KPH
^=3
Parameter Customisation Screen
All pre-defined parameters were cancelled using the 'C

icon,
the screen was now similar to that below.
Signals ^ (n> •S'- rz^ S.I.
ABSWL
BAT+P20
BAT+P3
FLS2
FLW<133
FLW>133
FRW<133
V
V
V
A B C
1 2 3 ^ ^ i i C
V
KPH
KPH
KPH
Datalogger Main Menu
Fig. 35 Parameter Setup
The rectangle below the play icon next to 'ABSWl' (Anti-
lock Brakes System Warning Lamp) was selected to be

recorded.

The rectangle below the 'eye' icon in the 'ABSWl' row
was selected to be recorded.
The screen was scrolled down until 'RIW<133' was

displayed.

The rectangle below the play icon in row'RLW<133'was

selected.

The rectangle below the eye icon in row 'RLW<1 33' was

selected.

September 1996 9-63

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