HAMBURG: Forget about rust and worn-out engines. Digital ageing is more likely to spell the death knell for old cars, as the circuit boards and transistors used in them degrade to the point where they simply no longer work.

The problem lies in a car's ECUs, shorthand for the electronic control units. These tiny circuit boards are programmed to operate many different aspects of a car from regulating fuel injection through to winding electric windows.

When introduced in 1967, the ECU units were hailed as a triumph of new technology. These days they are cursed by many a cherished-car owner who cannot track down spares.

When an ECU stops working as a result of a defect or physical ageing, it needs replacing and there is the rub.



Many cars from the 1980s, 1990s and some only 15 years old are considered worthwhile classics, but electronic control items for these are no longer available. Stocks have dried up and making new ones is prohibitively expensive.

Anything up to 100 different ECUs can be found in an upmarket saloon or sports car built say 25 years ago. If the defective programmed boards cannot be replaced, these cherished vehicles could end up as static exhibits with no chance of them ever being used again on roads.

"You can get an old purely mechanical engine to run again and rusty metal can be replaced, but software is not so easy to repair," said expert Stephan Joest. He works for the Fédération Internationale des Véhicules Anciens (FIVA), an international body which supports owners of older road vehicles and lobbies on their behalf.

ECUs are crucial to the smooth running of a car, whether it be a bread-and-butter model or something rare and exotic such as an Aston Martin Lagonda wedge or a Mercedes-Benz 250 Coupé.

The ECU used for the German car's fuel-injection system contains 270 separate electronic components.

To keep upcoming generations of classic cars running is a challenge to carmakers. Some like BMW and Mercedes-Benz have enlisted the help of parts suppliers such as Robert Bosch, which produced the original electronic gubbins and can sometimes supply replacement kit.



FIVA expert Joest wants to see the setting-up of a comprehensive register of ECU circuits before it is too late to save cars which are still in daily use, but which are destined to be future classics.

"We must save the digital source-codes used by these devices so that they can be used in future," said the FIVA expert. His concerns have not fallen on deaf ears, and component and tyre supplier Continental is already working on a solution.

"This problem is certainly on our radar and we are looking for the best way to solve it," said Continental's Enno Pigge.

The software is not the only problem, points out Klaus Reichert, who heads Mercedes-Benz Classic Service and parts. Items can be recoded, yet electronic regulating parts are not designed to last for ever.

"The half-life of an ECU is a lot less than that of a front wing or bumper," he said. Physical damage is much easier to detect and predict.

Digital ageing means a lot of electronic components kept in reserve as spare parts are simply dead in the box, although they have never been used. The same applies to diagnostic equipment used to pinpoint ECU faults.

"We first got to grips with this problem in 2012," said Reichert and since then Mercedes-Benz has establish a network of specialists and companies capable of refurbishing ECUs just like engines.

Circuit boards for more recent cars are already being stockpiled and should be available as spares for some time to come. Volkswagen has embarked on a similar strategy, said the company's classic car guru Joern Schwieger.

Reichert said he was confident that a current S-Class limousine or an AMG-tuned Mercedes-Benz sports saloon will enjoy the same kind of retro-parts service as modern rarities like the 600 Pullman from the 1960s or the even more venerable gull-wing 300 SL sportster.

It is worth noting that manufacturers and their parts suppliers are under no obligation to maintain spare parts once a vehicle is no longer in production. Some firms do however keep a back catalogue of key electrical parts for owners of modern classics.

Digital ageing can even affect fairly new cars. The McLaren F1 supercar can only be maintained and its software updated using an obsolete Compaq computer from the 1990s. McLaren has scoured the world for the device, buying up as many as it can find in order to keep F1s on the road.

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