ECU count

[Baron von Teuchter]

I’ve read a few things online about this, what do we think, is it really only seven? I know the ethos was simplicity above all else but I seem to recall Lyn Calder saying in an interview it was something like 25 (compared to 75 in a new “Defender”.)

Really only 7?

 

[Baron von Teuchter]

My screenshot missed out the G-Wagen with 150+ ECU’s…

 

[Granite Deer]

In addition to the problems you cited, more control units means more to update, with more complexity. Case in point: https://www.cbsnews.com/news/ford-vehicle-recall-software-issue-february-2026/

Motor Trend claims that a Grenadier has 37 ECUs: https://www.motortrend.com/reviews/jonny-lieberman-first-test-2026-ineos-grenadier

Rivian made a major push with their R2 platform to simplify their electronics platform, and did a great job of it.

If Ineos did keep it to 7, and can improve on what they have, it’ll be a big win for us owners over the long haul. I think 37 is much more likely, though. I have experience in the automotive electronics industry. It is likely that the 2026 gained ECUs to support things like driver-attention-warning.

 

[AWo]

My 2 cts.

- What do they claim what an ECU is?
- Depends on the ECU - Changing an ECU can be much more easy than changing a differential or an automatic gearbox or an engine or other mechanical stuff. My Defender Td5 has one ECU and the spare ECU is with me on long trips. In my Defender Td4 the turbo ECU failed a few years ago, easy to swap, two screws one plug, done. Same with our Isuzu DMAX, the exhaust sensor was dead, two screws, a cable and the sensor, very, very easy to access as the Isuzu is very clean and sorted under the car. As long as you do not leave the planet, the spare part will reach you. On the other hand, you can't change the rear axle of a Discovery 5 without a computer....
- You will not be able to prevent a minimum of ECU's because of the legislation.
- A Tesla has one ECU, the only thing I like Tesla for, they made the right approach here, as they had not to deal with decades of integrating more and more ECU's from hundreds of vendors...but....you need the money to do that and an error is on you alone.
- The number of ECU's is not relevant in my perspective, what the ECU does is the thing. Just think about the steering failures of the Grenadier due to a defect ECU. One important ECU is enough to stop your journey....other cars might have more, but do every ECU you count always stop you if it fails?In general the cars today are more vulnerable to hazards. Wrong fuel, wrong oil, wrong PCV, wrong this, wrong that....that is not related to any ECU, but to the advance in technology. More power, less consumption, less emissions and less driver responsibility...etc. There are so many other reasons you can get stuck...broken CV-Joints for example....
- Even if the Toyota or the G (no information on the ND) has more ECU's they seem to have them better under control and they have less errors than Ineos does with 7 ECU's. So it is not just about the number, it also about the quality. Our 2024 Toyota Hilux GR Sport shows exactly zero errors and updates over the air were absolutely flawless, yet.

The really bad thing with electronics, in my perspective is, it becomes more and more difficult to let a car age to become a veteran/classic car. Not just because of the ECU's but also due to the fast model changes and the non-interest of the car manufacturers to provide spare parts for more than ten years. If you take care about the oil pan, it lasts 50, 70 and more years...but the plastic one....same with intake manifolds and all the other stuff.....when this plastic shit is gone its gone....

AWo

 

[Granite Deer]

My 2 cts.

- What do they claim what an ECU is?
- Depends on the ECU - Changing an ECU can be much more easy than changing a differential or an automatic gearbox or an engine or other mechanical stuff. My Defender Td5 has one ECU and the spare ECU is with me on long trips. In my Defender Td4 the turbo ECU failed a few years ago, easy to swap, two screws one plug, done. Same with our Isuzu DMAX, the exhaust sensor was dead, two screws, a cable and the sensor, very, very easy to access as the Isuzu is very clean and sorted under the car. As long as you do not leave the planet, the spare part will reach you. On the other hand, you can't change the rear axle of a Discovery 5 without a computer....
- You will not be able to prevent a minimum of ECU's because of the legislation.
- A Tesla has one ECU, the only thing I like Tesla for, they made the right approach here, as they had not to deal with decades of integrating more and more ECU's from hundreds of vendors...but....you need the money to do that and an error is on you alone.
- The number of ECU's is not relevant in my perspective, what the ECU does is the thing. Just think about the steering failures of the Grenadier due to a defect ECU. One important ECU is enough to stop your journey....other cars might have more, but do every ECU you count always stop you if it fails?In general the cars today are more vulnerable to hazards. Wrong fuel, wrong oil, wrong PCV, wrong this, wrong that....that is not related to any ECU, but to the advance in technology. More power, less consumption, less emissions and less driver responsibility...etc. There are so many other reasons you can get stuck...broken CV-Joints for example....
- Even if the Toyota or the G (no information on the ND) has more ECU's they seem to have them better under control and they have less errors than Ineos does with 7 ECU's. So it is not just about the numer, it also about the quality. Our 2024 Toyota Hilux GR Sport shows exactly zero errors and updates over the air were absolutely flawless, yet.

The really bad thing with electronics, in my perspective is, it becomes more and more difficult to let a car age to become a veteran/classic car. Not just because of the ECU's but also due to the fast model changes and the non-interest of the car manufacturers to provide spare parts for more than ten years. If you take care about the oil pan, it lasts 50, 70 and more years...but the plastic one....same with intake manifolds and all the other stuff.....when this plastic shit is gone its gone....

AWo

Indeed, it depends upon what you consider an ECU.

While Telsa has highly centralized compute clusters, I’d argue that it does not have only one ECU. It has one high-performance compute cluster, but it has dozens of ECUs by most definitions. Tesla examples include:

• Infotainment computer (MCU)
• Autopilot / FSD computer (HW3 / HW4)
• Vehicle control computer

Teslas also include zonal compute cores, which are discrete and almost certainly included in the OPs list of other manufacturers.

ECU replaceability is also changing over time. As code is now often secure-signed, it may require a dealership to replace one. It’s no longer the days of an ECU managing just the basics like spark advance. That’s when they were easily user-swappable. Good times.

One important ECU is enough to stop your journey....other cars might have more, but do every ECU you count always stop you if it fails?In general the cars today are more vulnerable to hazards. Wrong fuel, wrong oil, wrong PCV, wrong this, wrong that....that is not related to any ECU, but to the advance in technology. More power, less consumption, less emissions and less driver responsibility...etc.

^^^ So true! And highlighted by the fact that Tesla’s MCU can fail (the main and only screen goes totally black) but the car is still drivable. You lose your speedo, your map, and all internal controls for HVAC and infotainment, but the steering, brakes, and motors still work fine.

 

[Brad@SuperiorCO]

I consider the window down control, an ECU, so 4 for the windows, etc. I would believe the 37 ECUs, not 7.
Maybe the 7 was a typo from 37?
Or maybe there are only 7 ECU that will stop us on the trail and put us in limp mode, or undriveable?

I think grenadierparts.ch has a typo.

 

[landmannnn]

The number of ECUs is less of an issue than people worry about. Aside from the main ECUs (engine, transmission, body control etc) there are many smaller modules controlling the ABS, airbags, power steering and similar.

Back in the 90s and 2000s an ECU looked like this


Plenty of resistors, capacitors, diodes, power transistors and a handful of ICs. Many points of failure and not well sealed against the environment.

This is a typical modern ecu (this one controls airbags). Like your mobile phone, machine soldered, a protective coating and therefore not anywhere near as prone to failure.


Agreed, 30 or so ECUs is far more believable than 7.

 

[emax]

It's no use having "just a few" control units in the car. The concepts are still catastrophically flawed.

For example: If you can't put the transmission in neutral (because some ECU "forbids" it), you simply can't move.

Perhaps the emergency measure of unlocking the transmission from underneath will help. I've never tried it myself. But if you're stuck in a muddy ditch or a small stream with 40 cm of water, you're in for a real treat. You can't even pull the car out of the mud with the winch.

That's exactly the case with the Grenadier – not just in the event of a breakdown, but whenever the engine won't start for some really stupid reason. Try moving your car half a meter forward to, say, get to your bicycle in the garage, which is blocked because the Grenadier is too close.Impossible! Without starting the engine, this isn't possible – which is, for only a few seconds, extremely bad for a cold engine.

It's a flawed concept. I've owned several automatic cars, but none of them had this iditotic restriction. Even if all control unit are functioning correctly, they are useless if one of them has decided that you're not allowed to start thje engine.

Think of:

• a dead battery
• an empty AdBlue tank
• an empty fuel tank
• a blown fuse
• any other another (non-)problem preventing the engine from starting.

There could be dozens of (harmless) reasons why you can't start your engine. Any one of them will ultimately prevent your Grenadier from starting.

 

[Baron von Teuchter]

Off topic and I haven’t tried with the Ineos but in some older 4x4’s you can slip the transfer box into neutral, allowing the car to roll whilst in gear, anyone tried this?

 

[AWo]

A guy in a podcast about cars told he had rent VW Passat. When driving back he always puts his arm behind the headrest of the passenger seat to turn his body to look through the rear window. And the first time he did so the car made a bumpy sound and stopped. He thought he has hit something small, got out but there was nothing behind the car. Ok, second try. Same thing happend again.

It took him some time to realize that there was a seat pressure sensor which detects if the driver is still in the car. If not, it puts on the brakes and stops the car. By turning his body he reduced his butt weight in such a manner that the sensor deteced that he has fallen out of the car while driving backwards. I assume, a situation everybody knows and has gone through several times....who has not fallen out of the car while reversing and though immediately...if the car would only stop now....

AWo

 

[AWo]

There could be dozens of (harmless) reasons why you can't start your engine. Any one of them will ultimately prevent your Grenadier from starting.

When I read this I thought about my army times.....we always had to and were ordered to park any vehicle with the front facing outward. This was done not only for "being ready" but also for emergency reasons like a fire. You could push and pull the cars and truck out if necessary without starting them.

My Iveco 90-16 truck has an air brake system. The parking brake brakes with the power of springs. Only when pressured air is available you can release the brake, as the air presses against the springs. That is the normal way how such truck parking brakes work. For that reason this truck had striking pieces you could hit with a hammer to release the brake in an emergency when you do not have time to start the engine and fill the air pressure tanks first.

AWo