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ABS Malfunction | 6.2 GT3


Pork Chops

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Cairns had a crap day, and then so did I.  My GT3 was just about ready to roll when all of the sudden the ABS pump starts, and won't stop.  Even when the key is taken out of the ignition.  The only way to stop it is to disconnect the battery.  They have done a lot of research into what's up and how to fix and have come up with nothing.  An auto elec is going to have a look over it first thing tomorrow as they've come to the end of the line.

Here is the sequence of what happened.  Car was in getting the suspension done, battery was in poor shape, car got jump started, threw some codes (as they do when the battery gets low), cleared codes which was successful except the ABS fault.

So it's either connected with the suspension work (it's not that), related to the low battery, or a random, coincidental failure of something.

The part is mega expensive so we can just throw a new one at it and see.

I would appreciate any ideas the collective might have, but a knowledgeable workshop has done quite a bit of homework so unless you've experienced it yourself, know of this situation, or have really good specific knowledge, please refrain from speculating as it's just going to clutter up the thread and get us nowhere.

Thanks in advance.

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While not porsche specific I have knowledge of another brand where a pump staying on was due to a relay failure. If the ABS uses a relay for the pump then removeing  it will confirm. If in this case it is electronically switched within the ABS unit the failure of the electronic switch could be due to the low battery (no under voltage lockout protection) or poor jumping practice causing a voltage spike that could also damage an electronic switch. Find and remove the ABS fuse(s) (could be more than one) as well as any relay associated with the ABS. The diagnostics for this is pretty easy given it is a steady fault. 

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http://www.mynrma.com.au/get-involved/advocacy/news/why-you-shouldnt-jumpstart-a-modern-car.htm

“Jaguar warned us that you could damage the whole wiring harness if you try to jump-start one of their cars, and quite frankly that warning is probably applicable to most vehicles built within the past five years.

“A five-year-old Audi was recently taken to an NRMA Approved Repairer with an electrical system so badly damaged by an attempted jumpstart that, in the end, it was actually cheaper to write the car off rather than repairing the damage.”

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The real problems start when disconnecting the leads. Preferably no engine should be running when you do this. At a minimum no engine should be above idle and have remained  connected and running for 10 minutes after starting. If the alternator (either one) is supplying current across the jump you will get a massive load dump and this can cause a lot of damage. Never ever double jump a modern car.

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The real problems start when disconnecting the leads. Preferably no engine should be running when you do this. At a minimum no engine should be above idle and have remained  connected and running for 10 minutes after starting. If the alternator (either one) is supplying current across the jump you will get a massive load dump and this can cause a lot of damage. Never ever double jump a modern car.

I'm not sure why you think this happened, or perhaps I'm misunderstanding you.  There were 2 separate attempts to start the car, first one failed, second one worked and once started I'd suggest the second battery (from which the car was started) was removed.  That's what I would do and it's what Toby described to me (Toby is as straight as they come).  So how is this 'double jumping'?

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Chopster

Maybe I've got this completely wrong!

Could this possibly be a systems management issue? My wifes BMW encountered a number of baffling systems issues for example disarming the airbag, tyre pressure sensors and ABS sensor indicator (although the ABS strangely still worked)  The problem was identified as a faulty systems brain box.  The catalyst for this issue was other non related electrical repair (after disconnecting the battery)

After much frustration and $$$ an authorised BMW dealer eventually identified the fault after a lengthily process off checking each protocol on the computers software.  Solution was to buy another brain box  $$$

The Kid

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I'm not sure why you think this happened, or perhaps I'm misunderstanding you.  There were 2 separate attempts to start the car, first one failed, second one worked and once started I'd suggest the second battery (from which the car was started) was removed.  That's what I would do and it's what Toby described to me (Toby is as straight as they come).  So how is this 'double jumping'?

Not suggesting it was doubled jumped just a side comment to never jump with more than 12V

Disconnecting the jump battery with the engine running is BAD and will cause an alternator "load dump" which results in a voltage spike . You can try to minimize the load dump by having the engine at idle or waiting 10minutes so the jump battery cN recover some charge minimizing the current flowing to it

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Not suggesting it was doubled jumped just a side comment to never jump with more than 12V

Disconnecting the jump battery with the engine running is BAD and will cause an alternator "load dump" which results in a voltage spike . You can try to minimize the load dump by having the engine at idle or waiting 10minutes so the jump battery cN recover some charge minimizing the current flowing to it

Got it.  Thanks.

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does PIWIS tell them anything?

What is PIWIS?  Just googled it and not sure but they've got a full diagnostic computer at the workshop.  I'm getting the car back this arvo with the ABS disabled as the fix is very unlikely to come this side of the weekend and my track day.  I'll drive it home and around a bit and see how it goes.  I'll then consider the risks and benefits of driving on the track with no ABS.  As long as the brakes function normally I'd say it's less dangerous doing so on the road as it's much less likely for an unforeseen braking circumstance on the track. Just have to brake at little earlier to be on the safe side.  I'll prolly not lose a lot of time as the ABS cuts in too early in these cars IMHO.

Who thinks this is silly :ph34r:?

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Sorry to hear. If you need mine to check anything or test you are more than welcome. 

Personally I don't think ABS disabled is an issue on the track. Maybe just dial it down to 95% and enjoy the day without worrying on beating your previous best. 

Dis anything come from the autoelectrician today?

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What is PIWIS?  Just googled it and not sure but they've got a full diagnostic computer at the workshop.  I'm getting the car back this arvo with the ABS disabled as the fix is very unlikely to come this side of the weekend and my track day.  I'll drive it home and around a bit and see how it goes.  I'll then consider the risks and benefits of driving on the track with no ABS.  As long as the brakes function normally I'd say it's less dangerous doing so on the road as it's much less likely for an unforeseen braking circumstance on the track. Just have to brake at little earlier to be on the safe side.  I'll prolly not lose a lot of time as the ABS cuts in too early in these cars IMHO.

Who thinks this is silly :ph34r:?

PIWIS = Porsche Integrated Workshop Infomation System . It has more features than any of the 'code readers' out there and is able to interrogate all of the systems in the car.

I'm pretty sure cup cars don't have ABS so you're a step closer to them if anything

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PIWIS = Porsche Integrated Workshop Infomation System . It has more features than any of the 'code readers' out there and is able to interrogate all of the systems in the car.

I'm pretty sure cup cars don't have ABS so you're a step closer to them if anything

I thought they did have ABS but a different type and calibrated for slicks.

Dry day tomorrow, you should be faster without ABS.......?

See you there

We'll see!

 

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I had an ABS failure in my 6.2 with devastating effects. 

Anyway, I'm a little wiser for it now and one thing you should also look into is the brake light switch... yeah crazy I know, but this is an Achilles heel to the ABS system. 

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I had an ABS failure in my 6.2 with devastating effects. 

Anyway, I'm a little wiser for it now and one thing you should also look into is the brake light switch... yeah crazy I know, but this is an Achilles heel to the ABS system. 

Did it happen in the moment or did you know of the fault and drive without it?  Either way sorry to hear you tale of woe.  Can't say I'd be that comfortable driving on the road without it.  Track is much easier as unforeseen events are far fewer.  Have to get mine fixed ASAP.

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How did it go out there last week Nick? Any side effects on track with running without it?  ABS is the one thing that Porsche got horribly wrong on the 996 GT3 IMO

TBH it was better without it on track.  The only time I missed it was when it was lightly raining as a high speed lock up would have been be scary.  It was much easier to control the brakes and you can brake much deeper, including trail braking without the ABS.  Had a couple of lock ups but they were really minor and not scary at all.  Kinda cool seeing plumes of smoke!  Another story for the road though so need to get it fixed ASAP.

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TBH it was better without it on track.  The only time I missed it was when it was lightly raining as a high speed lock up would have been be scary.  It was much easier to control the brakes and you can brake much deeper, including trail braking without the ABS.  Had a couple of lock ups but they were really minor and not scary at all.  Kinda cool seeing plumes of smoke!  Another story for the road though so need to get it fixed ASAP.

That is very interesting. I really dislike the way ABS intervenes at the track and find it's there pretty much at all times during heavy stops and is off putting? It seems clear that it was calibrated purely for the street and not for the track at all. I can see why you'd want it for the road but it's food for thought if it's only a matter of pulling a fuse before a track day...

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That is very interesting. I really dislike the way ABS intervenes at the track and find it's there pretty much at all times during heavy stops and is off putting? It seems clear that it was calibrated purely for the street and not for the track at all. I can see why you'd want it for the road but it's food for thought if it's only a matter of pulling a fuse before a track day...

It's a good thought as I reckon I'd rather no ABS on a dry track.  I'll get an image of the connector and find out how easy it is to just pull it on a track day.  Do your own research on what else it affects but clearly I did a track day with it pulled so was reasonably confident nothing else was affected, and nothing occurred during the day to give me any concerns.

I wonder how much $$ and effort to upgrade to a Cup ABS set up.  I know there are guys in the US who track their cars who do this mod, but wonder how well that would work on normal tyres and on the road.  Probably not that well.

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It's a good thought as I reckon I'd rather no ABS on a dry track.  I'll get an image of the connector and find out how easy it is to just pull it on a track day.  Do your own research on what else it affects but clearly I did a track day with it pulled so was reasonably confident nothing else was affected, and nothing occurred during the day to give me any concerns.

I wonder how much $$ and effort to upgrade to a Cup ABS set up.  I know there are guys in the US who track their cars who do this mod, but wonder how well that would work on normal tyres and on the road.  Probably not that well.

Thanks mate that would be good! I will have a chat to Buiks here in Adelaide before I go to the track next as well to see if they have any experience on the matter. I know lotus guys used to switch it off for their track days for similar reasons without fail but every application is obviously different. I'd imagine the issues would have been fairly apparent at the track if there were going to be any though. The cup car ABS is like 5K for the unit 2nd hand if you can find one and probably another multiple thousand to get it hooked up properly (or maybe not that difficult)   But I think a lot of those guys run Hoosier slicks so not sure how well it would work with r-comps. The ABS really does shit me though. One minute it feels like the car is not going to pull up then suddenly it stops on a dime 

/end my ABS rant!

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Did it happen in the moment or did you know of the fault and drive without it?  Either way sorry to hear you tale of woe.  Can't say I'd be that comfortable driving on the road without it.  Track is much easier as unforeseen events are far fewer.  Have to get mine fixed ASAP.

it triggered the "abs warning" right before the failure, when the system fails you simply have little to no stopping power... it's gnarly as hell and gets you by surprise because that stopping power you're used to having, it's just not there. I would urge anyone with that fault to just tow  the damn car to a shop before it does the damage. 

 

Interesting to hear your feedback on no abs on the track, sounds like a valid reason for why they dropped ABS in the 997 Cup! 

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