Computers have changed cars out of all recognition. The current
trend ensures ever more sophisticated engine management and electronic
systems being fitted to even the smallest and cheapest of cars.
The use of complex electronic systems by vehicle manufacturers is
not just limited to engine performance or emission standards, but
many other vehicle systems, such as air bag, safety restraint systems,
electronic dash boards, climate control, in car entertainment, imobaliser,
traction control, braking, steering and drive train are now electronically
controlled. The list just goes on and on.
In the very near future even the simplest of service activities
will bring the service technician into direct contact with the peripherals
of electronically controlled systems.
Also under European legislation all new vehicles Since January 2000
must have On Board Diagnostics (OBD).
It is not unusual to find 10,12 even 14 computers on one car, there
are some BMW's out there with 26 computers on board, all talking
to each other, so you can see how far motor vehicle technology and
diagnostics have come.
The latest advancement has been CAN bus systems or multiplexing
as it is sometimes known, this is where the on board computers all
share information from the vehicles sensors.
For example, an ABS wheel speed sensor will provide information
through the bus line to the engine management computer and the transmission
computer for road speed information. The same signal may be picked
up by the instrument cluster control unit to drive an electronic
speedometer display. The ABS computer will use it and the traction
control computer may also use it, so if that sensor fails it is
possible to have fault codes stored and logged in several of the
We then have to interrogate each of the computers to retrieve the
code, and then we need to understand the function chain of the system
to get to the root cause of the problem. Once the fault has been
repaired we then have to delete the fault codes from each of the
computers. Failing to delete the codes may leave the vehicle with
limited derivability or as often said in limp home mode.
We are an "Autocom" diagnostic centre, fully equipped
to carry out work on problems concerning the most up to date systems
i.e. fuel injection, engine management, ABS braking, traction control,
Climate control, Airbag, safety restraint systems, Dashboard correction
and diesel engine management, (yes diesel engines now have the same
amount of complexity)
We repair engine management related faults that other repairers
and main dealers may find difficult. We use the latest laptop PC
driven oscilloscopes to carry out fault finding and our vast array
of specialist equipment is up graded every 3 to 4 months via the
Parallel measurement is one of the ways in which we do measure vehicle
electronics. This way of measurement gives you the values going
into and out from the ECU*.
All the values are displayed in real time.
The connection to the car is fitted between the ECU and the ECU
harness using one of our cable adaptors
The Parallel way of measuring is in many cases the only way to
measure on cars from the time before OBD. But even on cars with
OBD the Parallel measure is of a great value when it comes to the
exact localisation of a fault.
*ECU = Electronic Control Unit
Serial measurement is the most common way to perform tests on
vehicle electronics. In modern cars a standard connector can be
found. From this connector we read the cars diagnostic system codes
and data’s. This diagnostic system is called OBD (On Board
By this technology it is in most cases also possible to activate
components, turn off service lamps, erase fault codes. test airbag
components, re-program imobaliser units,keys, and read Data.