1997 ASTON MARTIN DB7 fuel

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
Signal Description
lACDTCY Idle Air Control Duty Cycle (% open)
lAT Intake Air Temperature - °C or raw input counts
lAT STAT Air Temperature - Temperature sensor failure
lAT-V Intake Air Temperature - Volts or raw counts
IGN Desired Ignition Timing - ° BTDC
INDS Input from manual lever position sensor (counts)
IPWA Injector Pulse Width in mS- Bank A (Cylinders
1
-3)
IPWB Injector Pulse Width in mS- Bank B (Cylinders 4-6)
LAMSE1 Current Short Term Fuel Trim 1, adjustment from stoich - (% of range)
LAMSE2 Current Short Term Fuel Trim 2, adjustment from stoich - (% of range)
LFC Low Speed Fan Status
LOOP Fuel Control -1 = Open Loop, 0 = Closed Loop
MAF MAX Maximum Mass Air Flow signal during normal running
MAF Raw MAF sensor output (A/D counts)
MAF STAT Mass Air Flow Meter - MAF sensor failure
MIL Mali Indicator Lamp Status -1 = Lamp On
Mis HI Cumulative misfires detected by misfire test (Hi bit).
Mis LO Cumulative misfires detected by misfire test (Lo bit).
Mis nc HI Cumulative misfires detected by a misfire test (Hi bit).
Mis nc LO Cumulative misfires detected by a misfire test.
Misi HI Cumulative misfires detected by cylinder
1
misfire test (Hi bit).
Misi LO Cumulative misfires detected by cylinder
1
misfire test (Lo bit).
Mis2 HI Cumulative misfires detected by cylinder 2 misfire test (Hi bit).
Mis2 LO Cumulative misfires detected by cylinder 2 misfire test (Lo bit).
Mis3 HI Cumulative misfires detected by cylinder 3 misfire test (Hi bit).
Mis3 LO Cumulative misfires detected by cylinder 3 misfire test (Lo bit).
Mis4 HI Cumulative misfires detected by cylinder 4 misfire test (Hi bit).
Mis4 LO Cumulative misfires detected by cylinder 4 misfire test (Lo bit).
Mis5 HI Cumulative misfires detected by cylinder 5 misfire test (Hi bit).
Mis5 LO Cumulative misfires detected by cylinder 5 misfire test (Lo bit).
Mis6 HI Cumulative misfires detected by cylinder 6 misfire test (Hi bit).
Mis6 LO Cumulative misfires detected by cylinder 6 misfire test (Lo bit).
MISF Misfire Monitor - 1 = Currently misfiring
ODCODES Total number of on-demand codes currently stored.
PGM CVS DC Purge Management Duty Cycle (% on)
PIP Profile ignition Pick-Up - PIP input level
PNP Park Neutral Position Switch
R-BIAS1 Rear bias trim (Bank 1, cylinders
1
-3)
R-BIAS2 Rear bias trim (Bank 2, cylinders 4-6)
RATCH Lowest TP reading during driving
TP MAX Maximum Throttle Potentiometer signal during normal running
TP STAT Throttle Position Sensor - TP sensor failure
TP Throttle Potentiometer - Volts or counts
TPR-V Raw counts from sensor
TQ-NET Net torque into the torque convertor
TRIP OBDII Drive Cycle Complete (except cat monitor) - 1 = Trip completed
TRIPCNT Number of Completed OBDII Trips
VS MAX Maximum Vehicle Speed signal during normal running
VS STAT Vehicle Speed Sensor mode flag
VS Vehicle Speed - MPH
WAC Wide Open Throttle A/C Cut-Off -1 = High (WOT Relay)
September 1996 9-37

The Aston Martin Lagonda Diagnostic System
Users Guide ^?
Engine Setup
- 95 MY

Two adjustments
may
beset with the aid of the PDU
on 95

MY vehicles.
• Throttle Potentiometer
• Idle Fuelling Trim
From
the 95 MY
Main Menu, make
and
confirm
the

following sequence
of
selections:
Diagnostics
/

Manual
or
Auto Transmission
/

Engine
/

Engine Setup
/

The following connection diagram will then be displayed.
Throttle Sensor Adjustment
- 95 MY

Note:
The
throttle stop
and
throttle cable adjustments
must
be
correct before setting
the
throttle potentiometer.
On completion
of the
engine setup connections
the
test
selection screen will
be
displayed.

1.
Select Throttle Potentiometer.

2.
Turn
the
ignition switch
to
position
II but do not

start
the
engine.
3. Monitorthethrottle potentiometer bargraph voltage
at fully closed
and
then
at
fully open throttle.

4.
The
throttle potentiometer voltage specifications

are:

Throttle Closed
0.57 -
0.59V

Throttle Full Open
4.00 +V

Cable Setup
Diagnostic Socket D
Engine Setup Connections
Tinrottle Position Sensor
Value
:
0.43V

570
600

Idle Voltage
(mV)
Make adjustments as
necessary

Throttle Potentiometer Voltage
5.
If
both voltages
are
either high
or low,
loosen
the

two throttle pot screws and adjust the potentiometer
until
the
specified voltages
are
achieved. Carefully
tighten both screws ensuringthat the potentiometer
does
not
move during tightening.
6.
If
either voltage
is
unstable
or if the
specified
voltages cannot
be
achieved, investigate the cause.
If
the
potentiometer
is
replaced,
set the new pot

using steps
3-5
above.
Note:
On
automatic vehicles,
the
kickdown switch
adjustment check follows the throttle
pot
adjustment.
9-38 September
1996

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 =2?
Training
The training programme incorporated into the PDU
software is designed to cover the needs of new users and
those who have basic PDU skills but require further
training on the DMM and Datalogger functions.
Select 'Training' from the PDU main menu to bring up the
training menu.
New User Training
The new user training program takes the student through
a structured sequence of activities to learn the meaning
and use of the basic screen icons. The traineemay then
work through programmed exercises to learn the digital
multi-meter and then the datalogger functions.
Existing User Training Menu
in this program the existing user may select training from
the following list:
• User Screen Controls
• Digital Multi-Meter
• Datalogger
OBD II Scan Tool (Not 95 MY)
The OBD II Scan Tool is designed to access the memories
of the engine and transmission control units to monitor
and extract data relative to emissions control.
The following types of data may be accessed:
Current Powertrain Data
Monitor Freeze Frame Data
Request Trouble Codes
Clear Trouble Codes
Request Oxygen Sensor Test Results
Monitor Oxygen Sensors
Display Pending Trouble Codes
Request On-Board Monitoring Test Results
Examine Readiness Tests
Malfunction Lamp Status
The data to be monitored is selected from the OBD
11
main

menu.

For example if Monitor Freeze Frame Data is selected, the
system will display up to 11 parameters which are always
recorded when a fault code is logged. The parameters are
as follows:
0 : SUPP Supported
2 : FCFF Fault Causing Freeze Frame
3 : FSS Fuel System Status
4 : CLV Calculated Load Value
5 : ECT Engine Coolant Temperature
6 : STFT-B1 Short Term Fuel Trim - bank 1 (Cyl
1
-3)
7 : LTFT-B1 Long Term Fuel Trim - bank
1
(Cyl 1-3)
8 : STFT-B2 Short Term Fuel Trim - bank 2 (Cyl 4-6)
9 : LTFT-B2 Long Term Fuel Trim - bank 2 (Cyl 4-6)
12:RPM .Engine Speed
13:VS Vehicle Speed
•'••) •• 9-66 September 1996