Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - Response from Scion about rough idle problem

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Response from Scion about rough idle problem

Several of you already know this topic, but wanted to let you guys know I got this email (yesterday) from Scion officially responding to this article.

Toyota, Subaru chase rough idle problem for sporty coupes

Quote:

On October 4, Automotive News posted a story titled: Toyota, Subaru chase rough idle problem for sporty coupes.

Scion wanted you to know what we know.

In a matter of weeks of detecting a diagnostics sensitivity accompanied with rough idle phenomenon, we deployed an ECU update into production and to our customers. The condition is brought on by a combination of normal mechanical variables (similar to tolerance stack up) aggressively monitored by the ECU. Since this condition is brought on by mechanical variables (or tolerances); not all vehicles will experience the condition. Our field office engineers are coordinating the ECU update with our dealers

Early on, since the diagnostic trouble code that caused the check engine light to illuminate, directs technicians to replace the VVTi oil control valve(s) and/or camshaft timing gear assembly(ies) many of the early vehicles received new oil control valves and/or camshaft timing gear assembly(ies).

Some of our customers were inconvenienced due to a temporary short supply of parts (hard engine parts in the beginning and ECUs later on). We believe this temporary parts shortage has been resolved.

-Scion

Thanks! My car has that rough idle problem too... Hopefully this notice gets to our dealers here sooner than later...

Quote:

Originally Posted by DaJoian (Post 480264)

Thanks! My car has that rough idle problem too... Hopefully this notice gets to our dealers here sooner than later...

If not, print this page and show em lol

Thank you for the update. It's good to know of Scion's reaction and response to the matter on hand.

So what they're saying is that the original software was too picky, assuming tighter tolerances than actually exist, and throwing codes which tell the shops to swap out parts that actually were fine :P

I kinda wonder why Subaru only wants to reflash their ECU while Scion recommends changing the ECU itself for those who have over 100 miles... They are identical ECUs are they not???

Some of the FR-S owners already had their ECUs flashed and apparently that didn't solve the problem, so why is Subaru so confident that their reflash is going to solve the problem?...
(Assuming they are using the same flash update) :iono:

Oh...Twins...Always such a handful...

Interesting. Sounds like the mechanical tolerances were ''stacking'' or becoming additive as opposed to canceling each other out. This coupled with a sensitive ECU ''messed shit up''. Hopefully they fix the tolerance issue as that sounds like the root cause. I don't want a band aid, I want a cure. But it seems as if the problem has been identified which is great news.

"Stack up" is when part A is at one end of the tolerance and part B is at the opposite end of it's tolerance. Not really uncommon in the industry with the multitude of suppliers.

I feel great about this only being a software issue and nothing mechanical.

i sometimes get a rough idle (very rare) but iv yet to stall, and no codes thrown.

Posted this in multiple threads now; but here it is again...

Quote:

:( Experienced rough idle today on my way back from work.
When coming to a stop the LED DRL blinked off and then right back on when the car was on the verge of stalling approx 500 RPM.
After 10 minutes of driving and using the paddle shifters; the car all of a sudden idled fine again. :iono:

No CEL or TC light yet.

Called the sales rep today right when I got home; going to see if it happens again tomorrow...

I am beginning to think that ALL our cars will eventually get this problem inevitably. THIS HAS to be a recall.