Diagnostics

Vauxhall has been using many self-diagnostic systems on their vehicles since 1987. In recent times, self-diagnostic systems have been developed to cover the entire electronic network on all Vauxhall models. This means that even the smallest repairs require utilisation of specialist diagnostic equipment. I have the latest diagnostic equipment called Tech 2. This is the same diagnostic equipment used by Vauxhall dealers.

Tech 2 plugs into the OBDII (on board diagnostics 2) port found inside the car on all GM vehicles worldwide including Vauxhall/Opel. Using this, I can check for fault codes stored within any of the car's computer systems; check data from the car's computers; actuate system parts to check their operation; record data for later analysis; and program systems, including remote and transponder (immobiliser) keys.

Software Updates
Using Tech 2 it is possible to update most vehicle systems with Software improvement updates. Many faults can be rectified in this way, and can sometimes address the main fault which may have been undetected during other checks.  These software updates can only normally be carried out by a Vauxhall dealership.  However, the use of Tech 2 enables me to offer this service to customers.

Engine management
All Vauxhall engine management systems have self-diagnostic systems. If a fault occurs within the system, the orange engine management light will illuminate on the instrument panel to warn the driver that a problem has been detected. The computer will store the fault and send the system into default mode so that the car can be driven home safely or to a garage. A technician can then diagnose the fault using Tech 2 equipment.

Airbags
Airbags also have self-diagnostic systems and work in a similar way the above. Having detected a fault, the system will illuminate the airbag light on the instrument panel to warn the driver. In addition, the airbag system will automatically be shut down to prevent incorrect operation in the event of an accident. If the airbag light is illuminated, neither the airbags nor the seat belt pre-tensioners will operate in the event of an accident. The airbag system has to be plugged into Tech 2 and the system has to be reset once the fault has been rectified. Airbags should be replaced every 10 years to ensure correct operation.

Common Rail Diesels
Diesels have come a long way since the old noisy and dirty diesels of the Eighties and Nineties. We are now on 3rd generation common rail systems which are much more efficient and cleaner. This means however that the fuel systems run under very high pressures anything up to and 2000 bar (30,000 psi). This means the only people who should work on a common rail diesel engines fuel system are fully qualified vehicle technicians. These engines also now incorporate a particulate filter in the vehicles exhaust system which collects the soot created by a diesel engines emissions. After a certain mileage the engine management will perform a particulate filter regeneration by heating up the filter to approx 600 degrees Celsius to burn off the collected soot, this therefore prevents the filter from becoming blocked. You can tell if a vehicle has a particulate filter because the end of the exhaust will be completely clean (no black soot).

CAN bus
Later Vauxhalls Models launched From Vectra C onwards have a system called CAN-bus (Controller Area Network-Data Bus). This is designed to reduce the amount of wiring a modern Vauxhall would need to operate all the systems. It utilises data leads to transmit information around the car from one computer to another, rather like many PCs networked together in an office.