Jump-start caused computer failure

griffgruff

Hello everyone 🙋

My husband gave my son a jump start with jump leads the other day as my son's battery was down ..his did not start anyway and then ours wouldn't start as well ..nothing wrong with our car before that and now it looks like the SIM has gone down on the computer so the RAC man said ...has anyone come across this before? think it's going to be costly ..there is power going to the car all the electrics are working but he said the computer is not recognising the keys so needs a new SIM and reprogramming the keys 😱all I can see is £££ signs 🙏

mondeoman72

i recall seeing a Laguna with a warning sticker that the ECU was sensitive to power fluctuations and under no circumstances was it to be used for jump starting or receiving a jump start. I think this is what has happened to you.

I imagine something is fried and you need a proper diagnosis.

Flinty997

A quick Google suggests yes it can do this.

Most important is to understand why the car did not start by own battery. Run flat, old, no used long time, what ever. No point to jump start if there was something serious problem and just hope the jump starting fix it.

The car jump starting by other cars times is over. There is no any reason to take a such a risk. Does not matter how safe you are, the empty battery sucks insane amount current. If he did not wait and cranked almost instantly after connecting the cables, the current withdraw was insane. Add top of that typical Irish car have around 50% charge on every given momen (what I seen), sure it kills car or two. We are back on the beginning, the car jump starting by other car times is over. Buy a car jump start package or battery charger.

PsychoPete

Had this a few times with Renaults, jump starting them could cause a fuse on the positive battery terminal to blow resulting in numerous warning lights,the vehicle might not start or if it did start it would stay running even if you took the key out of the ignition. Hopefully you haven't done too much damage, with more modern cars your best to use a booster pack

John.G

Doesn't anyone push a car these days to start it?, I thought that was the original reason for a heated rear screen, to stop your hands getting cold while pushing it in the morning.

maestroamado

I would disconnect the battery for a while as it may rectify itself...

chooseusername

https://www.boards.ie/discussion/comment/118827437#Comment_118827437

That's only on Skodas

maestroamado

I forgot to say earlier... are you sure your battery is 100%... i recently heard from a friend that a problem with toyota (cant remember what) broght to toyota main dealer... when they plugged it in it showed a fault and they started stripping and he stopped them... Don't know full story but battery replaced and all ok... it seems if the battery low in volts/amps it can show fault...