Bonn, Germany: Cars are getting smarter every year and it won't be long before a set of wheels books its own annual service and turns up at the repair shop with the cheery announcement: "Hallo workshop, here I am."

Connected cars are already communicating with car repair garages and these days a mechanic is more likely to use a laptop to search for malfunction codes than pull out the dipstick to check the oil level in the engine.

During a car inspection, technicians regularly gain access to the various vehicle subsystems by plugging into the on-board diagnostic interface.

Volkswagen was the first carmaker to introduce an on-board scanning system in 1968 and the current standard is OBD II.

Many modern cars now have their own SIM card - like the one used by mobile telephones. This means that they can communicate with the workshop.

"These are often SIM cards which are not suitable for speech communication, but rather for transporting large amounts of data," said Nicolaus Gollwitzer, head of the global telematics division at the Vodafone telecommunications provider.

These SIM cards are used to relay technical information which can even include the number of occupants in a car - sensors detect how many airbags are inflated if the vehicle is involved in a road accident.

Data can flow automatically, but only if a car is equipped with eCall, a feature which allows the vehicle to call the nearest emergency centre after a crash, even if no passenger is able to speak. The eCall system is due to debut in Europe from 2018.

"In every other case, the car owner must give his or her permission for the use of data transmitted or received via a SIM card," said Gollwitzer.

The umbrella term for all this data trickery is telematics and if a driver agrees to the exchange, the car and its periphery can enter into a useful dialogue. BMW already sends out online updates for its navigation systems instead of using hard storage like a DVD.

Cars can send their malfunction codes to the local workshop which helps diagnose on-board faults more quickly.

"If particular codes are given priority, the car can then transmit these to a workshop automatically and the customer can get in touch with a mechanic straight away," said Gollwitzer.

So when the car comes in for repair, replacement components are already in stock.

"This enables the entire workflow in the workshop to be streamlined and the customer can expect a detailed cost estimate over the phone before the car arrives," said Joseph Schlossmacher from Audi.

The work done on cars in garages will not change a lot in future, but there is much scope for the development of tools and services," said Ulrich Koester of Germany's ZDK car repair shop federation.

"In future, drivers will have access to more detailed information about faults without having to go straight to the repair shop," said Johannes Boos who works for Germany's ADAC motoring club.

Components maker Continental predicts that cars will be able to warn about impending faults, before they happen. In contemporary cars, warning lights indicate malfunctions that have already occurred and must prompt owners to seek the nearest garage for an immediate repair.

At present there is no standardized telematics platform which every garage is permitted to use, so owners are usually forced to approach an official dealership of their brand.

Both the giant ADAC and the trade are urging standardization. This would allow customers more choice when deciding which repair shop to use.

One tantalizing spinoff would enable a car to be electronically tuned via its SIM card.

For example, if the owner were planning an arduous run in the Swiss Alps with a full complement of passengers and luggage, the car's engine could be optimized to cope with the extra effort. The upgrade would be valid for four weeks before the SIM card restored the engine default settings.

dpa