ASTON MARTIN DB7 1997 Workshop Manual
Page 381 of 421
The Aston Martin Lagonda Diagnostic System 
Users Guide D-^? 
Vehicle Features 
The vehicle features screen illustrated below is used to 
identify the vehicle particulars and the model year. 
If Airbag - NO is selected, the vehicle is assumed to be 95 
model year. 
If Airbag - YES is selected, 97 model year is assumed. On 
completing entries in the vehicle features screen, the 
appropriate vehicle area screen will be displayed. 
Vehicle Features 
Transmission MANUAL IIBIE^^I 
Airbag IDS^I NO 
D 
Vehicle Area 
This screen allows selection of the vehicle system to be 
accessed.
 Only 4 systems may be accessed on 95 model 
year vehicles, on 97 model year cars, 8 systems may be 
accessed as follows: 
Vehicle Areas 
• Engine Diagnostic 
• Engine Datalogger 
• Transmission 
• OBDII Scan Tool 
• Climate Control 
• Anti-Lock Braking System 
• Airbag 
. lb Axol 
o 
PI 
mLM 
n 
WLM 
El 
Ku^ 
95 model year software 
Zytek Engine Management 
GM 4L80-E Transmission Controller 
Teves Mk II Anti-Lock Braking System 
Valeo Air Conditioning 
97 model year software 
EEC-V Engine Management 
CM 4L80-E Transmission Controller with OBDII 
Teves Mk IV Anti-Lock Braking System 
Valeo Air Conditioning 
PATS Engine Immobiliser 
Megamoss security system 
FMC Airbag system 
Autoliv seatbelt pretensioner 
9-30 September 1996  
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The Aston Martin Lagonda Diagnostic System 
Users Guide 
Cable Setup - 95 MY 
On
 selectingthe
 required
 vehiclearea,
 the selected
 software 
will be loaded and then the Cable Setup screen will 
appear. 
Connections will
 be
 shown directly
 to the selected
 control 
unit
 on
 95 nnodel year vehicles
 using
 the vehicle interface 
adaptor (VIA) and appropriate cables from the PDU kit. 
Select the specified interface devices and cables from the 
PDU kit and connect as shown in the diagram. 
Cable Setup - 97 MY 
On 97 model year
 vehicles,
 connections
 to the
 vehicle are 
made via the Aston Martin Multi-Protocol Adaptor and 
two diagnostic sockets for most vehicle systems. 
Cable Setup 
Upper Diagnostic Socket 
o 
Diagnostic Sockets - 97 MY 
The diagnostic sockets are located behind the passenger 
side underscuttle panel. 
Upper Diagnostic Socket 
Lower Diagnostic Socket 
The
 sockets are
 mounted on
 a
 bracket
 and
 labelled Upper 
and Lower. The following lists describe the systems 
accessed from each socket. 
Upper Diagnostic Socket 
Transmission Control Module (TCM) 
Megamoss Security System 
FMC Airbag System 
Teves Mk IV Anti-Lock Braking System 
Lower Diagnostic Socket 
EEC V Powertrain Control Module (PCM) 
PATS Passive Anti-Theft System 
Autoliv Seatbelt Pretensioner System 
Air Conditioning Diagnostics 
The Valeo air-conditioning system uses a unique 
communications protocol and therefore the vehicle 
interface adaptor (VIA) is required and is connected 
directlytotheair-conCPU inordertocarryout diagnostics 
work on the system. 
September 1996 9-31  
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The Aston Martin Lagonda Diagnostic System 
Users Guide "^7 
Establishing Communications 
when cable connections are completed, switch on the 
vehicle ignition. The electronic control units will 'wake 
up'
 and communication between the selected control unit 
and the PDU will be established. 
As communication
 is
 established with the selected system, 
a system menu similar to that below will be displayed. 
System Menu Selections 
The options for each vehicle system are described in detai
 I 
on the following pages but menu entries fall into the 
following general areas: 
Security 
• Datalogger 
• Diagnostic Trouble Code and 
Alarm History Monitor 
• RF Transponder Key Learning 
• Exit a 
o 
Datalogger 
The Datalogger function is described in detail using a 
worked example at the end of this PDU Users Guide. 
Diagnostic Trouble Codes 
This application enables the PDU to monitor selected 
control module trouble codes and provides the following 
functions: 
• Decode and display any trouble codes logged by 
the control module being monitored. 
• When supported by the module, decodeand display 
enhanced trouble
 codes,
 together with any count of 
the number of occurrences 
• Clear all of the trouble codes and freeze frame data 
logged in the control module. 
• Monitor other data such as the alarm history in this 
example. 
Note: The 95model year Zytek engine management 
system permits clearing of individual trouble codes 
selected by the technician on the PDU. 
System Specific Tests 
These menu entries cover special tests required to program 
ortest system specificfeatures. The following are examples 
of tests provided: 
Engine KOEO and KOER tests 
OBDII Readiness test 
Output State Control test 
Throttle Potentiometer track test 
Ignition Key Learn Menu 
Remote Transmitter Key Learn Tests 
Special Functions Programming 
PATS 
Security 
Exit 
Selecting and then confirming the exit option will return 
the PDU to the Main Menu. 
PDU Use 
In the following
 pages,
 the use of the PDU on each vehicle 
system is described. 
Engine Diagnostics 
Transmission Diagnostics 
Climate Control Diagnostics 
Anti-Lock Brakes Diagnostics 
Passive Anti-Theft (PATS) Diagnostics 
Security System Diagnostics 
Airbag Diagnostics 
Seat Belt Pretensioner Diagnostics 
After these system specific descriptions, the following 
general purpose functions are described: 
Datalogger 
Digital Multi-Meter 
Diagnostic Trouble Codes 
Printing 
Training 
OBD II Scan Tool 
User Self-Test 
9-32 September 1996  
Page 384 of 421
^27 
The Aston Martin Lagonda Diagnostic System 
Users Guide 
Engine Diagnostics - 97 MY 
Selecting Engine Diagnostics from the Vehicle Area screen 
brings up the following Engine Diagnostics Screen. 
Engine Diagnostic 
• Diagnostic Trouble Codes 
• KOEO on Demand Self Test 
• KOER on Demand Self Test 
• OBDII Readiness Tests 
• Output State Control 
• Throttle Checks 
• Exit 
o 
Diagnostic Trouble Codes (DTCs) 
On selecting DiagnosticTrouble
 Codes,
 the PCM memory 
will be scanned and any recorded DTCs will be decoded 
and displayed. 
The engine and transmission DTCs are integral to the On 
Board Diagnostics (OBDII) system and are ful ly described 
in the DB7 OBD II Diagnostics Manual. 
Before attempting to clear the logged DTCs, record all 
logged DTCs for use in subsequent fault analysis. 
All logged DTCs may be cleared by selecting the EEC-V 
EMS DTCs
 title.
 This will bring up the Clear
 (C)
 icon which 
may be selected and confirmed to clear all logged DTCs. 
Note that on clearing all logged DTCs you will also clear 
the associated timers, counters and fault history files (and 
extinguish the engine management warning lightfor North 
American vehicles). The OBD II readines test status will 
also clear down and a PI 000 (OBD II readiness test 
incomplete) trouble code will be set.. A full drive cycle 
(see DB7 OBD II Diagnostics Manual) must be completed 
to clear the PI 000 code if required. The PI 000 code will 
clear automatically after some miles of driving when all 
required tests have satisfactorily completed. 
Caution: If a transmission code is logged in the PCM, the 
TCM DTCs must be cleared first and then clear the PCM 
DTCs. If the PCM DTCs are cleared without clearing the 
TCM, the TCM code will immediately reset in the PCM 
when power is restored. 
Key On Engine Off (KOEO) and Key On Engine 
Running (KOER) On Demand Self Tests 
Before either the KOEO or KOER test will run, the engine 
coolant temperature must be in excess of
 BO'C.
 Select and 
confirm either the KOEO or KOER test. If the coolant 
temperature is too low, the Pre Test Engine Warm Up 
screen will appear. Start the engine and run until coolant 
temperature is at 80+°C. 
Pre Test Engine Warm Up 
Value : 41°C 
80 Engine Coolant Temperature {°C) 
Waiting for engine to reach 
normal operating temperature 
o 
KOEO Test 
As coolant temperature rises through the BO'C level, the 
technician will be requested to turn the ignition off and 
then on again. The KOEO test will then commence. Static 
inputs to the PCM will be checked and any faults detected 
will be recorded and displayed as DTCs. If any DTCs other 
than PI 000 are logged, go to the OBD II Diagnostics 
Manual and resolve the concern(s) using the OBD 11 
diagnostic procedures. 
KOER Test 
If coolant temperature level is below 80°C, the technician 
will be prompted to start and run the engine until coolant 
temperature rises above 80°C. As the temperature passes 
the 80°C
 level,
 the KOERtest will commence automatically. 
If coolant temperature is above the 80°C level, the 
technician wi
 11
 be requested to start the engine. The KOER 
test will commence as the engine is started. Dynamic 
inputs to the PCM will be checked and any faults detected 
will be recorded and displayed as DTCs. If any DTCs other 
than PI 000 are logged, go to the OBD 11 Diagnostics 
Manual and resolve the problem(s) using the OBD II 
diagnostic procedures. 
September 1996 9-33  
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The Aston Martin Lagonda Diagnostic System 
Users Guide ^-^z? 
OBD
 II
 Readiness Test Monitor
 - 97 MY 
SelectingOBD II Readiness
 Tests
 will bring up the following 
screen. 
OBDII Readiness Tests 
1
 of 9
 tests completed. 
Logged DTCs
 : 1 
The following tests have been 
identified
 as
 incomplete: 
MISFIRE
 ir 
1 C.C.M. 
CAT MON 1IPURGE
 MONII SAIR
 M"ONn 
02 SENS
 1l02
 HEAT
 II EGR
 MONTI 
@ 
This software monitors
 the
 status
 of all
 significant 
components and parameters required
 to
 control vehicle 
emissions. When the tests are satisfactorily completed, the 
test boxes wi
 11
 be empty and the PI 000 status code wi
 11
 be 
removed from
 the DTC
 list. 
If any problem
 is
 detected,
 the tests will be terminated and 
the status will be shown as
 on
 the screen above e.g.:
 1 of 
9 tests completed. Logged DTCs
 : 1 
Incomplete test titles will remain
 in the
 screen boxes. 
Completed test titles are deleted from
 the
 screen boxes. 
Details
 of any
 trouble codes
 may be
 accessed using
 the 
Diagnostic Trouble Code function. 
The tests incorporated into this routine are as follows: 
Misfire Monitoring 
Fuel System Monitoring 
Comprehensive Component Monitoring 
Catalyst Monitoring 
Purge System Monitor 
Secondary
 Air
 Injection Monitor 
Oxygen Sensor Monitor 
Oxygen Sensor Heater Monitor 
Exhaust Gas Recirculation Monitor 
Throttle Position Sensor Track Test
 - 97 MY 
This test
 is
 used
 to
 detect
 any
 problems with
 the
 throttle 
potentiometer track which could cause faulty throttle 
position signals
 to
 enter
 the
 PCM. Such signals would 
result
 in
 incorrect calculation
 of
 engine power demand 
and possibly create excessive fuelling and high emissions. 
Selecting Throttle Checks from
 the
 Engine Diagnostics 
screen will bring uptheThrottle Position Sensor Track Test 
screen: 
Throttle
 pot
 track test 
Throttle State: PART 
Value
 : 1.9V 
ov 
Throttle
 pot
 voltage 
Depress
 The
 Throttle Slowly 
5V 
o 
Follow the screen instructions
 to
 test the throttle position 
sensor track. The throttle must be moved slowly from fu
 I
 ly 
closed
 to
 fully open without hesitation.
 Any
 pause
 in 
throttle movement will
 be
 interpreted
 as a
 track fault. 
If
 a
 fault
 is
 detected, repeat
 the
 test several times
 to 
elliminate hesitant throttle movement errors from actual 
potentiometer faults.
 If
 a repeatable fault
 is
 detected,
 the 
potentiometer must
 be
 replaced. 
9-34 September
 1996  
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The Aston Martin Lagonda Diagnostic System 
Users Guide 
Output State Control - 97 MY 
This menu item provides a quick test of the basic electro
mechanical components controlled by the PCM. These 
tests should be performed in a key on engine off state. 
The selections available are: 
• Low Speed Cooling Fans 
• High Speed Cooling Fans 
• Set Electromechanical Outputs 
Low and High Speed Fans 
Selecting and confirming either the low or high speed 
cooling fans will run the fans at the selected speed for 5 
seconds to verify their operation. 
Electromechanical Outputs 
This selection will cause the following electromechanical 
devices to operate for five seconds 
Air Pump 
Fuel Pumps 
Canister Purge Valve 
Idle Air Control Valve 
Observing each device in turn as the PCM outputs are 
turned 'On' will enable the technician to verify correct 
operation. 
September 1996 9-35  
Page 387 of 421
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  
Page 388 of 421
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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  
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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  
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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