E C U Units

[Geordie 1]

I ,ve had my Prius in for a body repair after an accident.( not Toyota) They broke the ECU unit and had to replace it .They said it was faulty .I find this hard to believe.What have they done to the ECU unit that they had to replace it ?

[Grumpy Cabbie]

First point of call is to check the health of your 12v Battery. They are much smaller than a 12v in a traditional car and only generally last about 5 years. Are you on the original?

If the 12v fails it throws up all sorts of weird faults and errors, hence why it's best to check the 12v first than throw expensive parts at the car.

Chances are that the car doors were left open whilst the car was being repaired and the interior lights left on. Whilst this isn't a probablem in a traditional car with a large 12v, it can be in a Prius, especially an old and weak 12v.

Leave the car overnight and in the morning pop a suitable volt meter across the terminals. The 12v is in the boot. If you don't have a volt meter you can put the car in Acc mode and wind all 4 windows down and back up. If they're super slow (compared to when in Ready mode) or they splutter and the interior lights go out, then you have your answer.

In a traditional car the 12v has to be large to crank the engine over and when they fail the car turns over slower and slower and slower. With a Toyota hybrid the 12v is small as all it has to do is boot up a computer that then starts the engine via the HV Battery. The 12v will either work or won't and barely gives any notice it's failing.

At least check the 12v as it's much cheaper to replace (about £95 via Toyota) than an ECU!

http://www.toyota.co.uk/caring-for-your-toyota/service-and-maintenance/repairs.json

Let us all know how it goes.

[Joseph D]

I ,ve had my Prius in for a body repair after an accident.( not Toyota) They broke the ECU unit and had to replace it .They said it was faulty .I find this hard to believe.What have they done to the ECU unit that they had to replace it ?

In addition to what Grumpy has said, there are multiple ECU's in a Gen II Prius, so which one exactly do they say is in need of replacement?

[Cyker]

Could it have been damaged in the impact?

That said, I seem to recall it was a common thing in the past where people'd not turn the HSD off properly and go to work on it with all the electrics live and fry something!

[timberwolf]

Given the occasional posting, I would say that the electronics in the ECUs are not that well protected or especially robust.

An ECU can be damaged simply when changing the 12V Battery.

Or when fitting additional third-party gadgets.

Putting jump leads on the wrong way seems a pretty good bet to destroy one of the delicate ECUs.

[Geordie 1]

The accident was only a small one. It wasn,t my fault ,honest ! The car was parked and a car hit the wing and door at a slow speed .It was a £1500 repair cost .then they fitted the ECU at a cost £1000. The 12 volt Battery is only 1 year old and is OK. I just wondered if the repairers had wrecked the ECU during the body work repair and didn,t want to own up.They had previous about telling exactly what was happening,like saying there is a 3 day delay waiting for the car to be valeted when it was at Toyota getting the ECU fiited. The car is fine now and the body repair is very good.

[Grumpy Cabbie]

Then we're never going to know.

It could have been damaged in the accident and it could have been damaged when those not experienced in hybrids start tinkering. We could all speculate but get nowhere.

[timberwolf]

Maybe you were lucky, the original ECU could have been bad from new (a Friday afternoon job...), and it could've failed at some other time, now you've got a replacement hopefully better made than the last one?

[johalareewi]

(a Friday afternoon job...)

In Japan?

[timberwolf]

Yes, the Gen 2 Prius were all manufactured in Japan - the UK models all from one production line.

[Grumpy Cabbie]

I thought the problems only arose from one line producing early gen3's? The gen2 is normally rock solid.

But the OPs car is apparently fine now and the repair good.

[timberwolf]

There was only one line to make right-hand drive cars for the UK because Toyota didn't sell that many cars to the UK. I only added it to the sentence to add a little extra colour whilst saying that yes the cars were made in Japan, and yes I am sure Toyota or one of their many suppliers can make "Friday" afternoon mistakes. What really surprises me, is that despite the many recalls and Toyota even admitting to the American people that Toyota had lost their focus on quality, some of you still believe the myth that Toyota cars are reliable or that they don't have components that fail.

One of the recalls for the Hybrid coolant pump, was due to the workers damaging the insulation of one of the wires during the assembly of the motors.

[MEP's Yaris GS]

What really surprises me, is that despite the many recalls and Toyota even admitting to the American people that Toyota had lost their focus on quality, some of you still believe the myth that Toyota cars are reliable or that they don't have components that fail.

Just because quality has dropped doesn't mean its guaranteed to break or become unreliable though. Toyota's generally (obviously not 100% of the time) are very reliable brand of vehicle, doesn't mean they have to be well screwed together like Audi or VW. Build quality and reliability are two very different things in my opinion.

[Mike169]

Hi

There was a post on here about changing Prius disc pads, i know it's off topic but i hope you will see where i am coming from. He took the car to his local friendly guy who really got into a mess as fitting Prius parts is not the same as an 'ordinary car'. Cost him a small fortune in the end getting them done properly as the pads slowly come out due to regeneration or something.

What i am saying is you can't get your average mechanic to work on these cars, they work differently and often a main dealer or an approved repairer is the best option.

Regards Mike.

[timberwolf]

What really surprises me, is that despite the many recalls and Toyota even admitting to the American people that Toyota had lost their focus on quality, some of you still believe the myth that Toyota cars are reliable or that they don't have components that fail.

Just because quality has dropped doesn't mean its guaranteed to break or become unreliable though. Toyota's generally (obviously not 100% of the time) are very reliable brand of vehicle, doesn't mean they have to be well screwed together like Audi or VW. Build quality and reliability are two very different things in my opinion.

Depends on what quality of a product has been reduced. Akio Toyoda made the prepared statement to Congress he used the words quality and safety in the opening paragraphs and then explained how they dealt with defects.

Another myth, German cars are not reliable any more (if they ever were?). It is amazing how long a company can retain a reputation, despite evidence otherwise, in the case of VW I think it has probably been able to maintain the myth by TV adverts.

[Grumpy Cabbie]

Hi

There was a post on here about changing Prius disc pads, i know it's off topic but i hope you will see where i am coming from. He took the car to his local friendly guy who really got into a mess as fitting Prius parts is not the same as an 'ordinary car'. Cost him a small fortune in the end getting them done properly as the pads slowly come out due to regeneration or something.

What i am saying is you can't get your average mechanic to work on these cars, they work differently and often a main dealer or an approved repairer is the best option.

Regards Mike.

You can get others to do the work but they've got to know what they're doing. The instructions are out there and simple to follow, though my experience is that many garages/mechanics are too proud to bother checking.

Though most can't work out the foot operated parking brake, so God help you should they then try working on the car.

[cobh18]

"There was only one line to make right-hand drive cars for the UK because Toyota didn't sell that many cars to the UK."

Why would they need a separate line for the UK? Japan still drives on the left in RHD vehicles:) Surely they could build JDM and export vehicles (Australia, India, Pakistan, Indonesia, Malaysia, Ireland, Malta) on the same line, or is there another reason?

[timberwolf]

There were a number of lines within the factory making the Prius, for some reason, as I understood it, only one of the lines was ever used to assemble cars for the UK market. At that time, I believe the factory made other models and it is entirely possible that production for other countries, other models, even non-hybrids or domestic only models were made on that line.

[Grumpy Cabbie]

I heard there was one line for RHD cars including JDM models. That's why we get that strange card holder thingy below the steering wheel on the right. It's for Japanese toll roads.

I'd also heard the gen3 had a specific and seperate line for European models which could be why the EU gen3's are not as reliable as the US versions seem to be.

[MEP's Yaris GS]

I heard there was one line for RHD cars including JDM models. That's why we get that strange card holder thingy below the steering wheel on the right. It's for Japanese toll roads.

I can't see that being the reason the card holder is fitted, if so all other Jap built Toyota's would have it also wouldn't they? Although to be honest I thought it was just a PiP part for the EV charging point access card to be popped into. I didn't realised all mk3 Prius had them.

[Grumpy Cabbie]

I heard there was one line for RHD cars including JDM models. That's why we get that strange card holder thingy below the steering wheel on the right. It's for Japanese toll roads.

I can't see that being the reason the card holder is fitted, if so all other Jap built Toyota's would have it also wouldn't they? Although to be honest I thought it was just a PiP part for the EV charging point access card to be popped into. I didn't realised all mk3 Prius had them.

They certainly do, but it's not there on the LHD versions, or at least the US versions. (conversation about this matter years ago on a US Prius forum).

http://priuschat.com/threads/photos-of-rhd.59707/page-2

And a picture of a Nissan Leaf RHD with the slot too;

http://www.mynissanleaf.com/viewtopic.php?f=4&t=10933

I think all new Japanese built 'World' cars will have the slot. Obviously the Euro designed offerings Toyota are now giving are unlikely to need it.

http://en.wikipedia.org/wiki/Electronic_toll_collection

[kithmo]

I heard there was one line for RHD cars including JDM models. That's why we get that strange card holder thingy below the steering wheel on the right. It's for Japanese toll roads.

I can't see that being the reason the card holder is fitted, if so all other Jap built Toyota's would have it also wouldn't they? Although to be honest I thought it was just a PiP part for the EV charging point access card to be popped into. I didn't realised all mk3 Prius had them.

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