Damage to engine control unit by faulty jump start ?

[Yvonne Wilding]

Hello. We had a recent incident where my son flattened the Battery of our elderly Yaris by leaving the lights on. On returning to the car, he called out a local repair and tow depot who attempted to restart the car. They managed to get it running but it would not stay on so it was towed back home. When AA examined it next day they said there were several fuses blown and the body control unit was fried. Subsequently we have had the BCU replaced. My belief is that the BCU was damaged by the company that came out to fix it when it wouldn’t start and I plan to claim on their insurance. Does anyone know if the BCU can be burnt out spontaneously? 

[FROSTYBALLS]

Moved to the Yaris club.

[Parts-King]

I have seen some terrible (expensive) damage done by incorrect jump starting. It usually fries a main fuse which is obviously cheaper. Why would the company who came out to fix it do more damage than the original incorrect jump start by your son? Good luck making a claim, I think that might be very difficult for you 

[flash22]

nope, is the car running now ?? You will have to prove who caused the damage and that it wasn't faulty before they worked on it, TBH you will not get anywhere with making a claim, your word, against theirs

[Madasafish]

I assume it's your 20 year old Yaris.

A reasonable person would say that any electrical part on a 20 year old car is a breakdown waiting to happen and the extra stresses from failing to start/restart contributed to but did not cause its early demise.

 

(or the design life was about 12 years!)

[Yvonne Wilding]

30 minutes ago, Parts-King said:

I have seen some terrible (expensive) damage done by incorrect jump starting. It usually fries a main fuse which is obviously cheaper. Why would the company who came out to fix it do more damage than the original incorrect jump start by your son? Good luck making a claim, I think that might be very difficult for you 

Thanks for your reply. My son didn’t touch it. The call out company did everything.

[MikeSh]

With a very old car like that it's quite possible, even likely, that some earth connections are a bit resistive. When high currents flow this could cause damage.

So it is possible that the call-out did nothing wrong, but the car reacted badly.

As others have said you will have quite the task to prove that they actually did something wrong.

[TonyHSD]

Incompetence from whoever worked on the car at first place is most likely the reason and yes when incorrect jump start is attempted it is possible to fried the car electronics. Whoever is at fault is another matter and how would you be able to proof and if it is worth the whole process. 
Good luck with either of your decision. 👍

[Parts-King]

1 hour ago, Yvonne Wilding said:

Thanks for your reply. My son didn’t touch it. The call out company did everything.

Sorry-I read your son had jump started it

[flash22]

3 hours ago, TonyHSD said:

Incompetence from whoever worked on the car at first place is most likely the reason and yes when incorrect jump start is attempted it is possible to fried the car electronics. Whoever is at fault is another matter and how would you be able to proof and if it is worth the whole process. 
Good luck with either of your decision. 👍

They could well argue that the reason for the flat Battery in the first place was caused by a faulty ecu/bcm - imho its not worth the hassle, chalk this one up to experience and move on

[Guest]

Even "experts" get it wrong! I recall, some years ago, on one of the t.v. shopping channels (no I don't make a habit of watching them), Someone was demonstrating, allegedly on his own BMW, a Battery powered jump start. He had apparently deliberately allowed the car's Battery to go flat for the demonstration. Connected up the jump starter directly to the pos and neg, switched on the ignition and smoke started to appear from, I assumed, the engine computer. "Oh, that's not meant to happen." Cut quickly to studio!

I know the above doesn't help the o.p., but it can go very wrong even when done correctly.