Computers and your car

The first production car with a computer in it was the 1967 Volkswagen Type 3 ( Squareback ) equipped with Bosch D-Jetronic fuel injection. This system used 1 basic computer and had 4 inputs: engine speed ( rpm ) , throttle opening, engine temperature and manifold pressure ( a measurement of engine load). Ignition spark and timing were still standard for the day, points and condenser with mechanical and vacuum timing control. In 1977, the Oldsmobile Toronado came with a spark control computer, but fuel was still supplied by a carburetor and a mechanical fuel pump.

Fast forward 45 years. A BMW X5 operates dozens of computer modules on five different networks, running everything imaginable on the vehicle, from door locks to satellite navigation. A basic modern economy car may have as many as 30 separate processors in it, a high end luxury model may have as many as a hundred.

Something as common as a Toyota sedan runs on 100 million lines of computer code. By contrast, the Air Force’s new F-35 stealth fighter runs a mere 5.7 million lines of code. That 100 million may double or triple in the near future as onboard control systems become more sophisticated and take on new tasks such as automatic parking, lane following and active cruise control.

Like your computer at home, your car can have it’s software updated to correct some problems not foreseen by the engineers and programmers that designed and built it. Increasingly, a primary step in diagnosis is to check the software version, or calibration ID, in the control module in question. If a new version is available it is uploaded  into the vehicle and diagnosis is resumed.

This process is called “reflashing” and it is something we do here at Baker Road Service. It requires a dedicated computer, specialized software subscriptions and an interface module called a “ J-box”, short for J2534, the designation for the protocol by the Society of Automotive Engineers ( SAE ). We will explore this and other automotive subjects in later blogs, stay tuned. You can also follow us on Facebook at

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