Mazda 3 Gearbox & Transmission Problems

Transmission Control Module (TCM) faults are not unknown on these early Mazda 3s. Symptoms usually involve erratic shifting, a failure to select gear at all and having the car go into limp-home mode. The good news is that there are companies out there who can repair your existing TCM, which gets you around the need to buy an expensive replacement. By the way, from what I can gather, any replacement TCM should be plug-and-play with no need to have the new module coded to the car’s other systems.

It’s also worth noting that Mazda in the USA issued a Technical Service Bulletin (like a recall but not for a safety issue) for automatic 3s from this era fitted with the 2.3-litre engine. In some cases, the shift solenoid could lose fluid, leading to harsh shifts and shuddering when driving uphill. The fix was a revised solenoid design but the catch was that the unit lived inside the transmission, so to whole gearbox had to be removed and taken apart to replace the part in question.

Ford changed from the LW model to the LZ in 2015. The LW had a dual-clutch automatic, which was very problematic and should be avoided; the later LZ had a regular automatic transmission and has none of the problems that beset the LW. In short the LZ is worth buying, and can be compared to the Mazda3 and Toyota Corolla for reliability.

Virtually all of today’s automatic transmissions are ‘sealed for life’. That is, they are filled with fluid at the factory and never need checking or topping up with fluid. But the fluid does get hot and can be contaminated over time, so it’s a good idea to have the fluid changed regularly. Some auto transmission mechanics will say it should be done every 20,000 km or so, or every year, others will say something different. It is more important if a car has been used for towing, because the fluid comes under greater stress in that situation. But in your case, I would suggest you leave well enough alone and not worry about it.

Unless you are buying a manual I would rule the Cruze out, the automatic is trouble in that model and not worth the risk. If you do but a Cruze I would choose the 1.8-litre engine. Others to think of are the Hyundai i30, Mazda 3, or Mitsubishi Lancer.

The Focus is a good car with a serious flaw; it has a dual-clutch automatic transmission that gives trouble. I would happily have a 2012 Focus with a manual gearbox, but I wouldn't buy one with a dual-clutch auto. I'd be looking at a Japanese or Korean brand and going for something like a Mazda 3, Honda Civic or Accord, Hyundai Elantra with a good record of reliability.

It's probably easier to eliminate those that don't stack up, those being the VW Golf, Holden Cruze and Ford Focus.

All have transmission questions over them.

The best options would be the Mazda 3 and the Hyundai i30.

We have heard reports of problems with shift solenoids in the auto. It's not a big problem and I wouldn't be worried about the general reliability of the car once it's been fixed.

I couldn’t recommend the Cruze; there are too many problems with its auto transmission, as we have reported here at CarsGuide. Look at the Mazda2 or Mazda3, Toyota Yaris or Corolla, which are generally trouble free.

Since you live in a regional area, I'd go for maximum safety and comfort, not the sports model. But it depends on your budget. As for gearbox, an auto will make life easier and improve resale.

You could take your complaint directly to Mazda's customer relations people. You might get a hearing because the warranty had only just expired.