Can you use modern cars to jumpstart?

EddScott

EddScott

EddScott

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Managed the flatten the battery on my Impreza this morning. Mother has an 02 audi but I didn't want to use that because I've heard you can damage modern cars ECUs when jumpstarting.

Anyone know if this is the case?

Ta.
 
Long story long


After dropping the nipper off ar school (having first driven off with her door open - we were late and rushing) went back home to get mobile. On arrival BT man on doorstep to fix landline.

He takes a while and in my excitement to have broadband that didn't cut off ever 2 seconds and connect at 160Kb I leave the cars headlights, radio and wipers on.

Flat as a pancake. Least it gave the neighbours something to watch this morning. Only just resisted the temptation to do a "Basil Faulty" on the car.

Asked BT man for a start but he said he couldnt because it damages the ECU on the van (what he said anyway).

Worst comes to it, I'll go home at lunch, take the batt out and charge it off the mains.

Mother hasn't even paid for the car yet even though shes had it a month so didn't really want to kill it before she pays for it :)
 
I have mornings like that.

There's no way you can damage the ECU, provided you remember red to red black to black. :D

Just hook em up. :)
 
That is true - I have heard cases where you can blow the ECU when you jumpstart.

It's not something that happens often - But I have seen it happen for myself.... and it cost something like £300 to get the ECU fixed
 
I've heard issues with airbags being set off and delicate electronics being shorted out due to the current spike.

But this was around 1999 - 2000 so things may have changed.
 
It's actually more modern cars that are prone to it - Probably because of all the fancy electronics...

The ECU that blew for us - Was on a '95-'96 Toyoya Carina-E I think.
 
I thought it was bumpstarting that damages the cat. I did it enough times on the 214, running up and down the hard shoulder of the A55 when the battery died on the way back from Wales :D

I've read things about ECU's being damaged, but I thought this was if you connected the posi and earth to the battery terminals on the other car.

Connecting the earth cable to a part of the cars chassis is supposed to be fine.
 
I used a Fiat punto 2002 to jump start an old Ford Transit once and it worked OK.
 
Ive jump started loads of cars many many times, including one this morning, a kia sportage jumping a kia pregio (sp? import people carrier thing).
Never had a problem yet but with cars anythings possible.
 
So its the cat on the car being jumped that could be damaged? Not a problem ;)

Hopefully got a mate coming at lunch to help me out. Prolly get a new batt anyway. Its hard enough trying to sell an Impreza let alone sell one which won't start! :)
 
I think,as has been said, that it's unburnt fuel getting to the cat (and the lambo sensor) that does the damage. If it's just the battery that is flat then it should be ok, why not just use the jump leads to charge the Impreza?

I saw a Nissan Figaro being used to jump start a Range Rover last week :eek:
 
Cat fails due to misfires shocking the element to fracture, and subsequently the hneycomb isnt quite as free flowing as it once was, the fuel isnt too much of an issue in the short term.

It also puts a good deal of strain on the cambelt.

I guess there could be an electrical issue as theres not residual load as such from the starter motor cranking as the alternator starts to spin which could create a spike of some sort, rectifiers etc should prevent this happening anyway.

I'd personal just get it on charge for a while either with a stand alone charger or jump leads from a running car. If anything about that concerns you a solution is to disconnect the leads to the battery. Only time i've ever worried about ECU's is welding on a car, and even then its only for peace of mind rather than reason.
 
Jonny69 said:
Indeed, the crank is still driving the cambelt so it can't make any difference.
Click to expand...

When you bumpstart a car, there's quite a shock through the system as the engine catches, much more so than starting the car on the starter motor.

The crank will go from turning rather slowly to rather quickly when the engine fires, which will, in turn, jolt the cambelt.
 
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