The ford transit custom PHEV costs £4500 to replace the timing belt. Access issues mean dropping the hybrid battery and parts of the sub frame. Compare with the mk8 transit, i've done the wet belt myself on that and it requires no special tools (well, i bought a specific crank pulley puller for £20) and can be done in a day on the driveway. I believe in some markets the replacement schedule is down to 6 years for the new phev due to all the wet belt failures on older models.
So far my favourite brand to work on has been Mazda, the engineering is very thoughtfully done with consideration for repairs.
I hear a lot of praise for toyota but it's from people who haven't worked on a car themselves rather than mechanics and they must be talking about toyotas from a bygone era because i'm not impressed with a 2019 corolla engineering at all, specifically various parts of the electrical system. I believe that was the most popular car in the world at that time.
Tesla is remarkably well done. Simplicity is under rated. So much so i bought one with the intention to keep for a looooong time.
I've heard this from mechanics already 15+ years ago. Mazda seem to still have this reputation.
I wish there were more repairability scores for cars.
The engineering praise comes from the fact that if you are taking care of it, you will probably never have to work on it until it's well into 6-digit mileage. This remains consistent through pretty much their entire line with the one exceptional black mark really being the RAV4.
https://electrek.co/2025/12/03/tesla-model-y-named-worst-car...
>So much so i bought one with the intention to keep for a looooong time.
Good luck with that.
Making it a very complicated and expensive fix isn't what's saving your rescuer or mechanic from getting electrocuted while working around your car.
But there are two other things that make it a bit unfair for Tesla in comparison to other brands:
Often the cars fail official inspections because of rotten breaks - this happens when your drive carefully and the Tesla is using regenerative breaking instead of the real breaks. Simple solution is to force breaking from time to time (I.e. breaking in neutral). Another aspect is, that all the other brands have a mandatory inspection from the manufacturer before the cars will be tested by the independent check. This avoids that they will fail it, because the car will be repaired before it is checked by the independent inspection. This is not mandatory for Teslas.
Another source of good recommendations could be insurance companies. Cars with low reliability or very expensive fixes probably need more expensive insurance. But I don't know if this data is public or if you can tell apart the reliability from the repair cost.
Usually at that point someone puts in a new hybrid battery and sells it to someone else starting out driving Ubers.
Yes there is. Either nobody is engineering towards that aspect or it is a conscious decision, deliberating between two different buckets: bill-of-material cost per unit and estimated impact on your warranty & goodwill budget. Whatever is deemed to be cheaper will win.
Source: I work at an automotive OEM and one of my first projects almost two decades ago was how to anchor after-sales requirements into the engineering process. For example, we did things like introducing special geometry into the CAD models representing the space that needs to be left free so a mechanic can fit his hands with a tool inside. These would then be considered in the packaging process. If you consider these are two completely different organizations, it becomes a very tricky problem to solve.
Sticking to old/cheap cars seems like an increasingly good option with so many scare stories about the pain and extreme expense of getting modern cars, particularly EVs, repaired.
And the impending ban on new ICE vehicles seems likely to lead to more older cars being kept on the road for a lot longer.
Bless them, I would rather buy 10 shitboxes than one modern car (and that cost is about the same).
Huh? Every EV uses recuperative braking, how is this special to Tesla?
That's something that they should have taken into consideration when designing the car.
I'm in Europe. Never heard of mandatory inspection before independent checks. How would that even work, or be enforced.
If it is protecting that end users can plug arbitrary loads into, that is one thing - but this doesn’t sound like that?
Why did that fuse blow? Because if that is not addressed, it’s likely to just blow again.
That's exactly it. I understand the importance of safety but reading the list of complaints I just cannot believe that safety is the key driver for the design decisions.
> ISTA’s official iBMUCP replacement procedure is so risky that if you miss one single step — poorly explained within ISTA — the system triggers ANTITHEFT LOCK.
> Meaning: even in an authorised service centre, system can accidentally delete the configuration and end up needing not only a new iBMUCP, but also all new battery modules.
> BMW refuses to provide training access for ISTA usage
Everything about this screams greed driven over-engineering. Since when are error prone processes and lack of access to information better for safety?
We live in a world where everyone justifies taking user hostile actions with some variation of "safety". Software and hardware are locked down, backdoored, need manufacturer approval to operate even when original parts are used, etc.
I had a Toyota Yaris a couple of decades ago. Very reliable, very few issues. But some routine things like replacing headlights were completely bonkers. You had to wiggle your hand between some sharp metal parts to unscrew the back end of the armature. Sheesh, would it have been that prohibitive to add a few cm of extra space there?
"While Tesla’s pyrofuse costs €11 and the BMS reset is around 50€, allowing the car to be safely restored, BMW’s approach borders on illogical engineering, with no benefit to safety, no benefit to anti-theft protection — the only outcome is the generation of billable labour hours and massive amounts of needless electronic/lithium waste."
It's not a choice between 'ridiculously inaccessible with the potential to create more damage than your car is worth' and 'push to reset'. There are many options in between, some of which would be a happy medium between the two that protect both safety, the environment and the customers' wallet. Which BMW's solution clearly isn't.
(Of note: I drive a hybrid vehicle, and over 125,000+ miles of ownership I have replaced my front brakes once and my rear brakes three times now in five years.)
This is BMW we're talking about. Their guarantees are worth absolutely nothing if my experience is anything to go by and them accepting liability is not something you should have to pay 4K for if other brands can do the same thing under $100.
I had a doozy of a trip issue on one project, a motor would occasionally (not always, no real pattern, hot/cold/etc. didn’t matter) trip the breaker, requiring a sparky to come out and open up the panel to reset it. We tried a bunch of things, megger-ing the motor, testing peak startup current on each phase with a fancy meter, checking phase-to-neutral current (Larger than you’d think! But this was normal, apparently.)
Everything was normal. In the end all we could think something was weird about the contactor. They took it out (I was off site at the time) and took it down to the substation to test it out.
With three phases connected to the contactor (and nothing connected on the other side) they energised the coil, and with an almighty bang it tripped the main incomer and took the entire sub offline.
Turns out there was a manufacturing defect in the contactor and sometimes for a millisecond, if the phase of the moon was right, it dead shorted two phases.
So there, even when you know everything, you don’t know everything.
$1000 for the module with the fuse seems ok to me. Another $3000 to link the module to the vehicle is the outrageous part.
I’ve never had a fuse blow on a car less than 20 years old, and then it was due to shorts due to damaged insulation and bad grounds due to corrosion, which are legit problems that need to be corrected.
Also, unlike breakers, fuses are generally immune to issues with HF interference and the like - they work through basic thermoelectric effects which iron out all but the most extreme issues. If you’re moving multiple amps in a situation described as ‘RF’, or ‘high frequency’ in a DC system that’s not just noise!
That’s a real problem that needs fixing!
Not fixing the underlying problem behind a blown fuse (or constantly tripping breaker) is how your car (or house or whatever) burns to the ground.
Or you have a Lucas, in which case my condolences.
It‘s not. But there are some newer EVs (e.g. Mercedes and VW) that track brake usage and will periodically switch to using the disk brakes when there‘s danger of corrosion.
If that was the issue you wouldn't be allowed to change your wheels on the side of the road. They'd be locked down to the car and require a complex software procedure to guarantee they were swapped correctly and won't endanger lives.
This is a professional shop raising the issues. They are liable for how the repair is done. BMW is just liable to lose money if people can easily fix their car at some other, cheaper, professional garage.
If you would see how EV Clinic "repairs" Tesla batteries, you would not say they have any concern for liability.
Even the basic mechanical disconnect and lowering of the battery is far from simple (and requires A LOT more expensive tools than changing a wet belt - not because they are greedy, but because a lift that can lower such hevy battery costs a lot of money, mostly in materials), and that's not even opening it, making sure you don't get electrocuted when you work on it ect.
Btw, my petrol car had ugly rusty rear brakes. No way to pass the check. The car had manual handbrake and I used in every highway exit to slow down and removed rust.
But other than that I mostly agree, I don't think that the over-engineering is greed driven - but the EU Manufacturers (but honestly, even other ones) have a really hard time with anything software based. Be it in car or outside of it. But BMW is far from the worst on that front.
P.S: VW ODIS original diagnostic is based on Eclipse :D
That said, the synergy drive is by design a very robust mechanical system. It has no dog gears, clutch or torque converter. I'm sure this contributes a lot to their long life.
ICE vehicles would normally catch these issues sooner because you'd be pulling in a lot more often for oil changes (and a quick mechanical inspection is typically a courtesy at that time).
The only real issue in reality is thermal runaway
Refusing access to training isn't a BoM issue by any means. Neither is a repair process that's so error prone that it can do even more damage to the car. We are surrounded by evidence that manufacturers in every field are taking decisions that are hostile towards their customers in the chase for profits. With the rise of EVs with far fewer moving parts needing constant maintenance, the manufacturers had to shift to different revenue streams, like killing repairability and locking everything behind manufacturer approval.
This is a professional shop voicing the complaints, not a random guy trying to do a fix on the side of the road.
Imagine someone told you they work for Apple and the reason everything is soldered, glued, stacked in a way it will never survive disassembly, and every bit of software and hardware in the device needs the manufacturer's blessing to be replaced or just keep running is because it was cheaper and safer this way.
> it becomes a very tricky problem to solve.
It was a solved problem for everything mechanical where locking it down or preventing people from learning wasn't really an option. How did it become tricky again just now when we deal with far more flexible software and possibility to lockdown?
It's not excusable to do this to the product because of some hand wavey napkin math about liability.
Understand how people will interact with your product and then use that information to avoid doing things like routing power where firefighters want to cut and you'll accomplish the same thing without a stupid expensive hair trigger fuse.
I think you are intentionally misrepresenting this and moving the goalposts to make your point. GP blamed safety and liability for the way the process looks like, not the complexity of the task. When it comes to safety you bet that an improperly installed or inspected wheel or tire can be dangerous.
A short internet search tells me [1][2] that some sort of tire malfunction causes tens of thousands of accidents and kills hundreds of people every year in the US alone. That doesn't include wheel malfunctions (e.g. wheel coming off). Yet this isn't locked behind some manufacturer approval and proprietary tools.
How BMW chose to approach this is profit driven. The old money printing machine from ICE maintenance, repairs, and spare parts is slowing down so they come up with new ways of extracting money. Like making the lives harder and more expensive for any non-BMW shop to do repairs. They're not alone in this, other brands do the same.
> If you would see how EV Clinic "repairs" Tesla batteries, you would not say they have any concern for liability.
More moving of goalposts mixed with not understanding what liability is, and where it belongs. So you tell me what's Tesla's liability when EV Clinic "repairs" a battery.
[1] https://www.smithlawcenter.com/practice-areas/defective-tire...
[2] https://www.safetyresearch.net/nhtsa-gets-real-on-tire-fatal...
It started out with (nominally, voltage can rise and fall based on charge levels) (30S) 144V packs, (96S) 352V is very common and there are (192S) packs that do 704V (but that are marketed as 400V and 800V respectively).
You don't want to get zapped by any of these, it's middle voltage DC which is quite dangerous, so the fuses definitely have a safety aspect in case of a crash, they are to protect emergency personnel from touching the frame and exposed wiring. But that's in case of a very serious crash, your average encounter with a rabbit might set off the crash detector (which can't really know ahead of time how bad a crash will be) but has extremely little chance of resulting in exposed wiring. In the case of BMW that rabbit could end up being pretty expensive.
If you wear a seatbelt and eschew the most risky driving behaviors your chances of getting in a crash where the difference between 2005 and 2025 matters are very, very, very, small.
I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
And it ought to surprise nobody that trophy wives in 4runners show up with their vehicle in a statistically different state of repair than single moms in Altimas.
The big failures that you really want to avoid almost never show up on safety inspection data because they typically render the car much less drivable so they either get fixed promptly or the car stops coming around for it's inspection.
Toyota hybrid powertrains are more reliable than any other company, but other than that they are no longer special.
What kills the hybrids is that the kind of people who buy these sorts of "peak appliance" cars tend to be the same kind of people who'll obliviously let some critical fluid run too low. You get orders of magnitude less of that sort of behavior in taxi fleets.
Next time when the fuse switch in my home I'll buy new home. I shouldn't normally switch on auto-fuse again!
Fuse blows, so you know something went wrong, you check corresponding part, fix it, and enable/change fuse. Nothing special. In home perspective - it could be plugging too many energy needy receivers into one outlet.
To take a few examples from the article with likely causes (note I don't work for BMW, so this is pure speculation based on my own experience):
> BMW has over-engineered the diagnostic procedure to such a level that even their own technicians often do not know the correct replacement process.
The ECU, diagnostic procedures and service methods are being developed by a different org-units. One is engineering, which works towards their own development use cases. They might develop the on-board diagnostic interfaces. The service unit develops their own tester and have to develop their own procedures.
Engineering is usually late with providing real hardware & software samples, let alone a fully integrated car. The service unit might only get a working test car very late in the process and discover that the procedure is super complicated. By that point the car development is already too far along for major changes. Remember that most components have been specified and awarded to suppliers years ago by this point.
> And it gets worse: the original iBMUCP module, which integrates the pyrofuse, contactors, BMS and internal copper-bonded circuitry, is fully welded shut. There are no screws, no service openings, and it is not designed to be opened, even though the pyrofuse and contactors are technically replaceable components.
Engineering is not concerned with these issues, it's usually the service unit which needs to bring in maintenance requirements. A judgement call is being made whether an assembly that you source as a single part needs to be split up further. For example, if you split it up further, you now have more parts to manage. You need to provide logistics and must allocate space in your spare parts warehouses for these new parts.
That usually makes sense for expensive components. Here's another fact: the manufacturer allocates a warranty & goodwill budget for each car line, because the manufacturer has to pay dealers for these repairs if it falls into the warranty period or is judged to fall under good will. It's usually not in the interest of the manufacturer to have expensive repairs because of that.
It might also be that the repair is being deemed to dangerous, because it is a high-voltage component. Opening it up and tinkering with it might increase the risk of an electrical fire in the battery. It might be that this risk was judged to be higher than the repair cost.
> Additionally, the procedure requires flashing the entire vehicle both before and after the replacement, which adds several hours to the process and increases risk of bricked components which can increase the recovery cost by factor 10x.
No service unit wants these long flashing times, because it blocks a repair bay in the workshop. But it's usually because the EE integration has been developed in this way. It might need coding, calibration or just bringing up everything to the latest release.
Vehicle SW is super regulated, you need to fulfill a staggering amount of regulations. Look up UNECE-R156 SUMS as an example. It might be that the new parts comes with a newer SW version, which has only been verified and approved in combination with newer SW in the other components. This would require flashing ancillary ECUs as well even if they have not been changed to ensure release compliance.
> Even after we managed to open the unit and access everything inside, we discovered that the Infineon TC375 MCU is fully locked.
Look up UNECE-R155. Things like these are mandated, if not directly in the regulation then indirectly by making the manufacturer liable for any modification that somebody did to their car. It is practically required to lock it down.
Just a few points off the top of my head, the comment got too long anyway.
In that situation, if you bypassed the fuse, or just kept replacing them without figuring out why it blew (too much load on a specific circuit), you very well might burn your house down by catching the wiring inside your walls on fire.
If it’s something that it is easy to connect loads too, then that is probably not super unusual and easy to fix, because people do that all the time, and you know what is happening and how to fix it. But you do need to fix it.
If it isn’t, then that is very concerning, because something caused that overload, and without that fuse your wires would have caught on fire instead of the fuse blowing. Inside your walls.
Either way, fuses are an emergency measure to stop the wires from destroying themselves from overload. They are destroyed in the process of saving your wires.
And if you are doing this all the time? You’ve got a very big problem brewing.
Or if the tires are not the right size, especially in staggered setups.
If you come from a car that is FWD with AWD capabilities, it doesn't matter as much.
But BMW (at least the ones with the engine mounted longitudinally) which have xDrive are permanent AWD.
So either all EVs need to be scrapped forever, or BMW needs to engineer a more tractable solution to the problem, or BMW is overreacting and overcharging customers.
some are, sure - but most aren’t. Plenty of well maintained clean 2010 model cars on marketplace and Craigslist for well under 10k.
Sorry that you feel that way, it was not my intention. But improperly installed or inspected wheel or tire is A LOT less dangerous than crashed EV Battery. And in EU you have a lot of effort going even into this, Police can inspect (and does) the tire from the outside (+ regular mostly yearly MOTs). All new cars have to have pressure sensors in the tire. So I would say EU (where EV Clinic is present) is making a lot of the same strides to make everything around tires safer. And believe it or not, if you go buy any new car in EU, drive it 5 minutes and swap the wheels yourself, it'll flag an error! As the wheels need to have appropriate pressure sensors - that also need to be programmed into the vehicle for a lot of makes.
You think it's profit driven, I don't. Agree to disagree.
> More moving of goalposts mixed with not understanding what liability is, and where it belongs. So you tell me what's Tesla's liability when EV Clinic "repairs" a battery.
I was aiming at EV Clinics liability, not Teslas. And I can guarantee you that both Tesla and BMW take into consideration the bad press if someone, even non official mechanic, repairs their cars and then they kill someone/catch fire. Of course Tesla a lot less than BMW, I even have a feeling that this contributed more to how BMW does things, than profit.
It is.
> I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
That's unfortunately not an option. The problem with the 600 to 1000 V domain is that it is able to creep where lower voltage would stay constrained and high enough that it can jump small gaps and start arcing spontaneously. The fact that it is DC makes it more dangerous still. But from an economy and practical engineering perspective it makes perfect sense. Keep in mind that these cars are often built using Lithium-Ion packs (though fortunately we are finally seeing a change here towards safer options, even if they are slightly less dense and more expensive), so the electrocution risks are small compared to the thermal runaway risks.
Plus they have tons more auxiliary safety features like lane departure warning, forward collision warning, blind spot detection, better visibility, etc. And they are roomier, have more power, get better gas mileage, and have backup cameras and Apple CarPlay!
It is unlikely to blow again under normal use.
Then, almost no manufacturer that sells in the EU knows how to do this (Renault is almost the only one that doesen't have pyrofuses in the battery, almost everyone else has). The catch is, the routed power is not problematic, the problem is when something gets squished and redirects that routed power to somewhere else. Which tends to happen in a metal tincan.
Are you talking about the charging circuitry?
What are the requirements for the motor(s)?
I must say that I've been impressed with Dacia. Even the build quality is excellent - on par or beating VW. I've driven on Romanian roads so I can see why they would prioritize such high build quality.
All this assumes proper maintenance, especially oil changes.
NYS DOT does some good work with the salt and sand up here, heavy on the salt. Mother Earth has some high blood pressure up here as she turns rotors to rust.
My calipers (all around) are also in excellent condition after 150k and I've been told that it's an absolute surprise I didn't destroy them with how low the pads went on the last change...
There is a certain level of risk that is inevitable with moving multi-ton machines at lethal speeds, and deciding that this particular issue is where we are going to draw the line is dubious.
The point that "allowing this fuse to be replaced affordably is too much of a safety issue" is a cop out is valid.
If you have the parts and the will it's possible to keep any car running close to forever. That said if you've gotten to the point where the frame is totally rusted out then maybe it's time to consider moving on.
I think both are right. Engineering a modern car is really complex as you pointed out but the customer also has the right to say, "well that is what you are paid for". In the end the customer can just go to the next car brand.
I own a relatively recent BMW but it is only a mild hybrid diesel (4 year old M340D) and before I even received the car, they changed the whole engine and did not release the car until that was executed. That was done by the dealer, and i never knew what was the reason.
On the flip side of modern car engineering I once had a check engine light called the dealer and with authorization prompts on my side they were able to tell me some gas exhaust sensor was malfunctioning and I would be able to go there at my leisure, as it was not urgent. That was nice. When i bought the car I had 5 years of maintenance included and this is one of the nicest things about owning a car in modern times. They even call me when it is about time to do the maintenance asking for when I am available. I never owned top brand cars before but this is for me worth the premium so far as it is one less thing to organize.
Apart from the normal maintenance and the above I never had any issue with the car, and it is a very big difference between a 2001 Passat TDI(my youth car) or a Ford Torneo Connect(the car i am aiming to exchange for due to family reasons).
I'm sure BMW would love to not be liable in those cases if they could just decide not to be liable, but inspections and fuses presumably turn out to be cheaper than the settlements they'd otherwise be paying.
Who thought that was appropriate?
Motors, for instantaneous current, can easily exceed 100kW, some much much more than that.
Even assuming limitations to 100kW (which, would be very low for motor current), that's still 2000 amps at 48V. Remember, 100kW is ~134 hp.
I don't think it should be locked away to just the MFG, but it does need to be respected.
Most other things are easy to source, and anything made of steel can be fixed (zero rust, so far).
Also, the problem is definitely also the cables in your car. Moving to 48V would mean amperage would increase by 10-20x, which would mean cabling thickness would have to increase substantially.
All that to say that a wet belt should not even be used in the first place.
That kind of thinking along with some calcification of organizational structures in/around R&D teams seems to be the cause for the rather dysfunctional software development at the German car companies. Software dev doesn't thrive in this environment.
Volkswagen probably had the right idea on paper when they created Cariad as a subsidiary software development company to isolate the devs, but then they ruined it by importing their own culture into it again.
If you have car brand A that has a reputation for having catastrophically expensive failures in major components, and car brand B which just keep chugging along for decades, you will probably see an elevated failure rate for brand B since it is still driving, while brand A will not be failing since it has already failed so badly it has been scrapped.
In the abstract, if you have access you can look at the technicians manual, and see how many labor hours are allotted to various common repairs, you can even look at common problems and see what the common outcomes were to repair the vehicle.
Unfortunately, most people don't have access to this highly valuable resource.
When a system “malfunctions” only to the benefit of one side it’s not “an issue” as much as design.
Why don’t you run the same careful reasoning against any hostile action from any big tech company and see how it sounds? All the actions of Microsoft, OpenAI, Google, Meta, Amazon are just the result of unfortunate misalignment between teams.
If a flipped coin always lands how the person flipping wants it to land, it’s loaded, not misalignment between hand and coin.
I’ve seen how the sausage is made in corporations with more money and higher stakes than BMW. Once you get off the ground and see more of the bigger picture, you can’t unsee the hostile decisions that are compartmentalized from the people who just see the tiny bit in front of them and it’s easier to sell them that they aren’t doing anything wrong and it’s not a problem.
BMW has manufactured engines and cars for over a century and historically they were relatively easy to fix by anyone. Their image in the press never suffered because of bad unofficial repairs.
All of this is trying to find a retroactive explanation that fits the result when the real reason is staring you in the face: they make money by making the owner entirely dependent on BMW as much as possible.
Your explanations are flimsy and disproven by data or history.
You’d need to use silver plated copper buss bar as conductors, 150kW @ 48VDC is 3125 Amps. I’m not familiar with DC ampacity tables, but you’d need (9) 3” conduits each containing (3) #500 MCM conductors for a three-phase 3125A alternating current circuit. One foot of #500MCM copper weighs 1.5 lbs, so each foot would have 27 times 1.5 lbs or 40.5 lbs per foot.
150kW @ 400V is 375A, a single set of #500MCM can carry the current, 4.5 lbs per foot.
The risk of being shocked by 400VDC while using the car is essentially 0, so they use higher voltage to save on conductor material.
There’s no way in hell I’d ever open up an EV battery myself and I know enough to do it safely. DC is incredibly scary, make sure to discharge your start/run caps if you replace them yourself!
Otherwise, they make some very questionable engineering decisions for sure. On their motorbikes, you often have to disassemble half the bodywork just to change the battery; that's just beyond stupid. But like Apple, their products are kind of unique, so people deal with it.
> Romanian drivers do >90 kph on normal roads as well. Romania and Bulgaria have the highest road fatalities per capita in the EU.