RPM dip with A/C running
 

Update: TSB Fix Available

Here's the TSB download link for this issue:

Click Here

Anyone notice that when you have the A/C running and come to a stop the RPM would dip and then go back up? Dealer checked said was this was normal and all the new Subaru does it. Any thoughts?

It's not normal if it's severe and this is a documented issue with the twins. I've had the idle dip from about day 1. Bought mine in July '12. It usually goes away once the motor is warmed up, but it's embrassing to have someone in the passenger seat when the car is cold. They always ask if there's something wrong with the car. :thumbdown:

It seems to happen only when the A/C is running and I'm coming to a stop.

With the A/C on it's normal.

Not a fan of this car with AC on over 90 degree heat.. Too much of a drag to run the AC system.. Probably the main reason i'm going to add more low RPM focused mods to the car to battle this...

The A/C will toggle off if you floor it. Casual driving you shouldn't see or feel the A/C turn off.

If you turn on the A/C and the rear defroster at the same time it dips pretty hard, but then again you shouldn't be doing that. :P

Add an exhaust and most people won't notice a thing.

normal to me. most vehicles i driven, including family minivan had little RPM dip.

Same here, coasting to a stop sign/light in gear...when I get to around 8mph or less I put it in neutral and the dip happens.

Only with A/C on, the idle is totally stable without A/C. I do NOT think I am a candidate for the idle issue as that issue happens A/C on or off.

Sounds like everyone is saying this is normal when A/C is on, thanks.

What happens (in every car) is the A/C pulls a decent amount of electricity to run, so when the engine is turning at idle it is asking the alternator to pull harder to make more power to use the A/C. In older cars or cars with weaker electrical systems (my 90 240 for example) at idle if you roll the windows down the rpm's take a dive.

What other devices run off the alternator in this car? Even though I seem to have everything turned off on the dash/console I still feel like the alternator kicks in constantly. I'd like to turn everything completely off and see if it makes a difference to my idle.

I think the load on the engine itself to run the compressor is much more of the problem than the load on the electrical system.

It happens to me too and its not the idle dip issue mentioned above.
only occurs during rpm drop to idle and the AC compressor kicks in
and drops the rpms too low, then it quickly recovers after stumbling
and then is stable..
Only when the engine is not engaged to the trans when coming to a stop.
Not every time.. but happened a few times to me under those conditions..
IMO.. Its a software glitch..
otherwise i find the idle with compressor cycling to be very smooth and
transparent in operation.
mid 90's tomorrow forecasted.. Raven in the hot sun = :evil:

The electric power steering system is quite power consuming at times..

Good catch, forgot to mention that!

Glad I found this thread. My brand new BRZ has less than 500km on the odometer and I noticed this last night.

Like you guys, only with the AC on and only when idling.

With AC off the car idles perfectly at around 600 RPM.

Doesn't happen anymore since flashing with OFT.

same here with A/C on it dip. What is OFT

Open Flash Tablet.

Exactly.. Not all the time.. But under certain conditions, when coming to a stop, the idle dips and the engine shakes as it recovers... Then it's fine again even the with compressor cycling on and off..

Every single car I've owned and driven dips with the ac on.

Definetly normal, every car i've owned does this. As others have stated, the engine has to compensate for the load of the a/c coming on, since the a/c cycles (satys on for a few mintues, turns off, vice versa), the engine has varying loads. it's important to remember when you're at idle your throttle plate is closed and the engine is running of the idle air control which doesn't flow much. especially when there are other loads on the system as the engine idles (power steering being used? radio loud), it can put quite a strain on an engine running at 700 rpm only flowing 2 g/s air.

http://www.ft86club.com/forums/showthread.php?t=61708

Bam! Just came out yesterday. :)

RPM dip with A/C running
 

This while is not normal, it is to mr.frs I think it could have something to do with the idle being too low and while coming to a stop the ac compressor load may cause it to stumble before recovering. I've started a thread here to discuss this along with potential fixes via tuning. I've been told(vendors here) that with a simple idle speed raise, the engine won't drop as low when the AC compressor cycles.

PS- i've even taken the car to the dealer to claim the TSB fix for this precise issue. They "flashed" and nothing changed. I say it in quotations because i think they did nothing. If it helps, i've been practicing my heal-toe while coming to a stop with AC on prevent this lol, gotta make the best of the worst.

Here's the TSB main page:

Click Here


Here's the TSB download link for this issue:

Click Here

Has anyone actually tried re-flashing already?
I have an openflash and have a different map on it, so it should have already fixed it. However, i notice this issue everytime.

I already did the tsb, not sure if is the same one as mentioned above but I would try to avoid taking my car to the dealer again. Hopefully once I tune the tuner could take a look at this. Seems that when the AC clutch kicks it drops the idle.

so has anyone tried the tbs for frs in idle dip when the ac is on ????

What i posted right above your post. I went, had it done and it didn't fix crap, all of this after a horrible and uncomfortable experience at the dealer. Had to ride with them so they could replicate the problem. Apparently at a given time during the day their techs become even more retarded, deaf and blind and they couldn't see the dip(almost stall) while coming to a stop with AC on. I think the only fix is to tune and raise the idle a bit.

Had the tsb done yesterday for my BRZ. Quick painless visit to the dealer, and it seems to have done the trick.

Is it fixed?

I recently flashed the car with Ecutek with @moto-mike and with his tune and a slight bump in idle speed, my idle dip is completely gone!! I think i'll be having nightmares for a while until i fully accept is gone. After living with it for a year and learning to heal-toe while coming to a stop to prevent it from happening, its fixed.

I just had the reflash done on my car. So far so good!