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Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Sat Mar 21, 2020 3:34 pm
by Scottyp1987
So strange results. Couldnt see any voltage change, just 12v constant to the motor. Frequency was all over the place, that should be constant shouldnt it? And no duty displayed. All tested using a multimeter with more settings than i realised. As i havent been in the office to get the scope.

As i had a spare h bridge channel ive tried it. I know its not the best idea, but i wanted to try it. It works exactly as it should. Goes to 20% target with key on. Starts and then goes to 4% on idle. Also revs up and moves as it should.

So my next question. Should i contact a syvecs dealer to look at it thoroughly or do i need to send my ecu and dbw throttle somewhere to get them checked? Guessing it would be better if somewhere had the whole car. There is a dealer close to me in milton keynes.

Thanks for you help btw, been very useful confirming checks/tests and expected readings.

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Sat Mar 21, 2020 4:08 pm
by stevieturbo
Not sure how either can be checked....maybe some settings caused an overload on the driver, or maybe there is an issue with the DBW unit itself that caused it to have problems with the driver.

Forcing too high duties all the time perhaps ? How long did it live for when it was running ?

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Sat Mar 21, 2020 4:49 pm
by TimH
S8 and S6+ H-bridge drivers were a weak spot (I don't know if it ever got changed/enhanced/improved as this was a few years ago).

I saw them get killed just by the car stalling. The customer I'm thinking of killed 2x S8's. Another killed 3. And I know of 2 or 3 S6+ units that died in odd but similar circumstances too. It was a nuisance for sure!

I suspect you're another victim (just call it unlucky if you like) and should be able to get the ecu repaired and thereafter will hopefully be OK!

There may be an argument for using an external H-bridge driver as a sacrificial device should it fail (one of my customers did this). There's the original "black box" Syvecs unit which, as fars as I know, was totally totally reliable and is £150 or so. The customer who killed 2x S8's went for our MEU as they needed more inputs anyway - gets you GPS as well but very definitely overkill at nearly £600 (apologies for the unashamed up-sell :) !

Gloom and doom apart, and if this is what's happened here, then I believe the reason for the fail is that the DBW motor (like other motor/solenoid devices) is an energy store and in the event of an untidy system shut down (e.g. battery volts low causing a stall, or inappropriate use of a kill switch) the energy needs to be dissipated somewhere. Since a DBW motor *only* has connections back to the ECU (i.e. no direct power or ground connection) then the energy can only be dissipated via the ecu...and the reverse voltage and current spike can take out the H-bridge driver mosfets in some cases (a discrete design was used, I believe, rather than an automotive-grade drive chip with heavy protection built in).

I think/hope you'll find that Syvecs will repair this for you :)

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Sun Mar 22, 2020 6:08 pm
by Scottyp1987
Stevieturbo i bought the ecu end of 2018 and had it fitted last year. Think i got the car back around july and only used for occasional weekends then off the road oct/nov. So not long 🙁.


Wow, thanks for the info TimH.
I never knew they were. Thought i was paying for the best ecu out there with no issues lol. Cant all be perfect though with electronics.
Ill have a look at an external controller as id rather have an issue with that than do anymore damage to the ecu or have potential to.

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Tue Mar 31, 2020 10:26 am
by TimH
Syvecs have contacted me to confirm that improvements were made to the s8 and s6+ H-bridge designs a few years ago. Think you should contact the supplying dealer and see what they suggest?

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Tue Mar 31, 2020 10:43 am
by stevieturbo
Well it can do no harm.

The way things are at the minute it could be a good time to do it, or a bad time if they're shut.

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Tue Mar 31, 2020 10:59 am
by Ryan.g
Just to add to this, The S6+ and S8 Designs for the H Bridge are very different.

The S6Plus in this case is well protected and very powerful! but the only aspect which can cause a issue is if the voltage on the supply goes above 20v.

In 99% of applications this will never happen but in some cars with older wiring, Jump starting with a booster pack that increases the voltage, can cause a large flyback on the 12v supply. This can hurt one component on the early board H bridge.

As with all manufactures improvements were made to deal with this scenario but its rare to happen.

If you ask your dealer to return with an RMA Form then we can see if this is the case and look to repair/update

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Tue Mar 31, 2020 8:25 pm
by Scottyp1987
Thanks for the info everyone. Ill contact them and see what they say

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Fri Apr 02, 2021 11:21 pm
by Scottyp1987
Bit of a late reply but just wanted to say thanks again. My ecu was all sorted out by syvecs and ended up being upgraded to s7 internals as they had stopped supplying/stocking parts for the s6.
All happy and no issues since :)

Re: Supra with syvecs s6 plus and porsche DBW throttle issue

Posted: Sat Apr 03, 2021 9:48 am
by stevieturbo
Good result