This highlights how difficult it is to build fuel-saving technologies.
As computers become more pervasive in just about every piece of technology we use, both digital and mechanical, the problems we encounter are bound to stem from pieces of faulty code more often than they did before. Planes and cars, which started out as analog as can be, are now governed by pieces of silicon and lines of code. It’s why in the world of transportation, the repercussions for faulty software are tremendous. Take the Boeing 737 MAX 8 as an example. Two of them fell right out of the sky and killed everyone on board simply because a software program on the plane was not properly designed to account for errors in sensor readings.
But the stakes can be similarly high for cars, as GM’s ignition scandal has uncovered. Fortunately, a recall announced by Mazda is a better example of the less-grave errors computers can cause. The problem isn’t small for Mazda, however, even if it’s relatively easy to fix. It all centers around the software Mazda’s ECUs use to regulate cylinder deactivation.
The automaker recently found that the software behind the Powertrain Control Modules (PCM), specifically the part of it that controls the hydraulic valve clearance adjuster, can go awry during the transition between cylinder deactivation states. In plain English, that means the software controlling the valves when they switch between fuel-saving cylinder deactivation modes and back to normal full cylinder operation, can glitch.
The result of that glitch is an engine stall and possible contact between the intake valve rocker arm and internal engine components. Thankfully, the fix involves nothing more than a software update to the PCM. Vehicles affected with the faulty software are the 2018 and 2019 model-year Mazda6 and CX-5 as well as the 2019 Mazda3.
Mazda said it is so far not aware of any accidents or injuries stemming from the problem. Still, the recall is not a good look for the automaker, especially since it recently had to recall the Mazda3 hatchback for wheels that may not have been properly tightened.
Recalls like this highlight one area where car computers can still evolve. Some automakers, starting with Tesla, have given their vehicles the ability to receive updates like this over the air, making software patches like this much easier and less expensive to fix.