Jump starting - damages the car?

[zcacogp]

Chaps,

A quickie.

I was talking to a neighbour the other day, and he mentioned that he doesn't jump start his car, neither does he offer to jump start other people, as it damages the ECU of his car. The car? An early-90's Volvo.

I have never heard of this before, is it true? And is it a problem isolated to Volvo's, or are all cars at risk of ECU damage if jump started, or used to jump start another car?

I've been on both ends of the jump start cables, and never had a problem, but then I have never owned a 'modern' car. (Having said that I have had cars with ECU's, and they have never suffered.)


Oli.

[Mafioso]

bks

[Carfiend]

BMW say to jump start from the provided terminals not directly from the battery. Only reason I know this is due to a friend with an E46 M3 who had it jump started from the battery and it damaged some computer or another which had to be replaced.

[Carlton Banks]

I had better contact many manufacturers and send them the link to this thread.

They will then remove the +ve & -ve terminals from their engine bays.

[morgrp]

I've jump started st loads of Volvo's over the years and never buggered one yet - if done correctly I think it carries minimal risk - get it wrong and it can be fked up

[944fan]

zcacogp said:

Chaps,

A quickie.

I was talking to a neighbour the other day, and he mentioned that he doesn't jump start his car, neither does he offer to jump start other people, as it damages the ECU of his car. The car? An early-90's Volvo.

I have never heard of this before, is it true? And is it a problem isolated to Volvo's, or are all cars at risk of ECU damage if jump started, or used to jump start another car?

I've been on both ends of the jump start cables, and never had a problem, but then I have never owned a 'modern' car. (Having said that I have had cars with ECU's, and they have never suffered.)


Oli.

Kind offer, but no thanks. In answer to your question I believe your neighbour done be talking bks.

[Carlton Banks]

I suppose if you put the leads on the wrong way and attached one of them to the end of your kn0b, perhaps there may be problems.

Maybe this is what your neighbour has experienced?

[Remagel2507]

Carlton Banks said:

I suppose if you put the leads on the wrong way and attached one of them to the end of your kn0b, perhaps there may be problems.

Maybe this is what your neighbour has experienced?

But seriously I have known people to fry ECU's by not connecting the leads properly or the wrong way round - mainly on Renaults actually

[SplatSpeed]

can only damage the car if it switched on at the time and then i am finding it really hard to work out why?

[EDLT]

Damaging a car while jump starting is a skill only taught to service advisers.

[Marlin45]

[QUOTE]Chaps,

A quickie.

I was talking to a neighbour the other day, and he mentioned that he doesn't jump start his car, neither does he offer to jump start other people, as it damages the ECU of his car. The car? An early-90's Volvo.

I have never heard of this before, is it true? And is it a problem isolated to Volvo's, or are all cars at risk of ECU damage if jump started, or used to jump start another car?

I've been on both ends of the jump start cables, and never had a problem, but then I have never owned a 'modern' car. (Having said that I have had cars with ECU's, and they have never suffered.) [/QUOTE]



Same applies to modern Ford's with 'Smart Charge' such as Focus/C-Max/Mondeo...... manual states if you jump start you could fk up the ECU/sub modules and comms nets quite rotally!

Edited by Marlin45 on Tuesday 8th February 16:00

[edo]

Jump starting caused some electrical issues on my Audi A8.

I've also been told push starting can cause issues with catalytic converters.

[CampDavid]

Maserati forums advise charging the battery, not jump starting as jump starting often causes lots of ECU faults and has been known to kill control units, meaning your friend is probably correct to a point.

Personally I would always check the owners manual. If it says you can jump it then jump it. If it says charge the battery separately then that mean you should charge it separately.

I guess the problems down to a power surge maybe?

[russell_ram]

CampDavid said:

I guess the problems down to a power surge maybe?

More of a power surge than connecting a fully charged battery to a car that doesn't have a battery fitted ? - can't see it .

Why won't the 'flat' battery will act as a huge capacitive surge damper ? Must of jump started hundreds of 'modern' cars without issue - some so 'modern' that their not even in market yet.

Russ

[CampDavid]

russell_ram said:

CampDavid said:

I guess the problems down to a power surge maybe?

More of a power surge than connecting a fully charged battery to a car that doesn't have a battery fitted ? - can't see it .

Why won't the 'flat' battery will act as a huge capacitive surge damper ? Must of jump started hundreds of 'modern' cars without issue - some so 'modern' that their not even in market yet.

Russ

No idea. Fluctuations in current? Spike from the alternator.

Either way, it seems that some cars plain don't like to be jump started. Either that or all the people claiming to have broken their ECUs from jump starting are part of some hateful organisation that hope to bring an end to the practise of jump starting cars from slave batteries. Can't see it myself.

[Carlton Banks]

CampDavid said:

Maserati forums advise charging the battery, not jump starting as jump starting often causes lots of ECU faults and has been known to kill control units, meaning your friend is probably correct to a point.

Personally I would always check the owners manual. If it says you can jump it then jump it. If it says charge the battery separately then that mean you should charge it separately.

I guess the problems down to a power surge maybe?

This is only a practical solution if you have time.

The times I have required to jump start my car are airport trips, being late for work, being the only remaining person at work etc.

[J4CKO]

Havent damaged one but have created an impromptu double bar electric fire

As for the early nineties Volvo, wouldnt be that fussed about it really myself.

[rufusgti]

Interesting. Only the other day I was helping jump start my friends Clio cup with jump leads from the battery from my clio cup. We were waiting for his mechanic friend to turn up(Renault dealer mechanic).
When he turned up he quickly removed the leads and told us never to try that on renaults as it will fry one of the ecu's (he was slightly more technical than that).
He then started it with a battery jump pack from inside his van. I'm not sure what difference this is to doing ot from another car. I'm also unsure whether he was implying i could damage my car or the car i was trying to jumpstart.
I can only presume he knows what he's talking about and has seen issues arise from jumping.

[CampDavid]

rufusgti said:

Interesting. Only the other day I was helping jump start my friends Clio cup with jump leads from the battery from my clio cup. We were waiting for his mechanic friend to turn up(Renault dealer mechanic).
When he turned up he quickly removed the leads and told us never to try that on renaults as it will fry one of the ecu's (he was slightly more technical than that).
He then started it with a battery jump pack from inside his van. I'm not sure what difference this is to doing ot from another car. I'm also unsure whether he was implying i could damage my car or the car i was trying to jumpstart.
I can only presume he knows what he's talking about and has seen issues arise from jumping.

I jump started our Megane from another car, it tells you to do it that way in the owners manual. It also tells you to attach the negative lead to the chassis, which is impossible as the whole engine bay is plasticoated

[The Wookie]

The ECU's in later 928's are reputedly quite fragile and have been known to be killed by the power surges that jumpstarting can create.

Personally I've jump started the GTS quite a few times (titchy battery and ropey electrics), and never had a problem, but that doesn't mean I never will!