Draper 54732, Instructions Manual

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Nearly all engines found in modern vehicles
are fitted with a number of sensors and an
Electronic Control Unit, which is often
referred to as an ECU.
The function of the engine sensors is to
constantly send information to the electronic
control unit (ECU) which monitors the
performance of various areas of the engine.
The ECU then analyses the information it
has received and determines whether the
values are within the manufacturer’s
permitted specifications/tolerances, minor
changes in value can be compensated for
by the ECU. For example it can adjust/
determine the correct injection duration.
However, if the ECU receives information
from a sensor and the value is outside the
manufacturer’s permitted
specifications/tolerances then the ECU will
recognise this as a fault as it is fitted with a
pre-programmed self-diagnosis system.
The ECU will then store the corresponding
code in its memory for retrieval at a later
date and in some cases will set the
corresponding code in its memory for
retrieval at a later date and in some cases
will set itself to run on a pre-programmed
emergency backup value otherwise known
as ‘mapping’. This allows the vehicle to be
driven to a garage or home etc. for fault
diagnosis and repair.
With use of a fault code reader the user can
read fault codes that are present at the time
of testing and the codes stored in the
memory of the ECU then referring to the
appropriate fault code reference tables the
fault can be located quickly and accurately.
These stored fault codes are output at
different times depending on the vehicle
make and model, i.e. stored
Ford codes are
output after the codes for any present faults
but Vauxhall codes are all output together
(both present and past stored codes).
The fault codes output from different
manufacturers are not the same and the
appropriate fault code reference table for
the particular vehicle must be referred to,
for instance,
Ford vehicles output two or
three digit codes whereas Audi vehicles
output four digit codes. In most cases the
codes will be displayed and read via the
fault code reader itself, however some
vehicles (
Vauxhall ) will be read by the fault
code reader but displayed via the vehicle’s
instrument panel.
Vehicles fault code diagnostic sockets differ
from manufacturer to manufacturer and this
code reader is supplied complete with
leads suitable for connection to
Ford and
Vauxhall vehicles.
NOTE: The Ford adaptor lead supplied is
suitable for use with the EEC-IV ECU.
Once all faults have been located and
rectified the fault codes can be erased from
the ECU memory. On some vehicles this is
carried out using the fault code reader but
others, such as
Vauxhalls, the power supply
fuse to the ECU must be removed, or the
negative terminal on the battery
disconnected for approximately one minute.
NOTE: If the battery terminal is
disconnected other items such as radio,
alarms etc. will need to be reset. ENSURE
you have the relevant codes to reset them. If
the codes cannot be erased as above then
they will automatically be erased after
approximately 20 cold starts (from cold to
normal engine temperature).
INTRODUCTION