KHC

I get a hesitation, then a surge when accelerating (ie. passing, changing lanes, speeding up on an on ramp)...it seems to be about a 3-5 sec hesitation. It is very annoying, especially when trying to accelerate into traffic and changing lanes. I do not have this problem in my 10 yo Toy Avalon. When I brought this in to Acura, the head mechanic told me that this is an inherent problem with all of Honda's transmissions because they are essentially use to making transmissions for motorcycles ( he mentioned something about "bands")

So some questions...anyone else experiencing this? and lastly, is this a bunch of BS?...I don't know anything about transmissions.

Thanks,

kurtis

mrdeeno

1) Yes, it is complete BS...I have never heard of an automatic transimssion in a motorcycle. So unless they recently started making auto trannies for motorcycles (in which case, they would not be "used" to it), or they started making a manual for the RL, this is a cop-out excuse.

2) I think it is not a "problem" per se, but the way the tranny "brain" is designed. I experienced the same thing duringy my test drive...when merging onto the highway and I gave it a lot of gas (not quite WOT), the tranny downshifted but then sllooowwlly sped up...no jerking whatsoever, even with a downshift.

I think this is either to prevent jerky downshifts or a way to prevent tranny damage since this is the same tranny that has had problems in past modes.

JMikeF

I would also venture to say that a moment's hesitation is do to 'drive by wire.' The computer is overwhelmed witrh data and has to sort it out. I've experienced this in other DBW vehicles.

1HOT NSX

I agree with the comment above that this is designed to make the tranny smoother, and the surge you feel is caused by the nature of the engine, i.e. the VTEC kicks in providing most of the power at the high end of the RPM band. I also agree that the motorcycle story is a bunch of BS. If you use the pads the acceleration is pretty much instantaneous.

Nocturnal

That seems highly unlikely. Every moment there is an identical amount of data to process and actuators to, well, actuate. There may be conditions that the ECU doesn't deal with properly though.

That said, I get great acceleration in 'auto' mode. Step on the gas and it goes. Sure there is some lag as the engine tries to get into VTEC range but that depends on speed and amount of throttle. From what you're telling us there -is- a problem with your transmission. I think someone else here had a loose vacum hose or something that caused drivability problems. Basically that caused the computer to not know exactly what was going on so it was making incorrect shifting decisions.

Did you get the transmission TSB done?

KHC

Thanks to all...and yes, I did get the transmission update a few months ago.

Perhaps I exaggerated on the hesitation...probably more in the range of a 3 sec delay, not 5 secs...all of this in auto mode. I will try accelerating with the paddles next time out.

So my impression from all of the replies is, sounds like this is inherent in the Vtec engine/Acura transmissions (so get use to it), but the reasoning behind it was a bunch of hooey.

I'm not familiar with the "drive by wire" terminology...elaborate?!

thanks again,

kurtis

Nocturnal

'Drive by wire' is an exageration because it's nothing like 'fly by wire' as used in modern airplanes but many modern cars no longer attach the throttle plate directly to the throttle pedal. Instead there's a sensor on the pedal and an actuator (stepper motor typically) that moves the throttle. The computer decides how far to open the throttle based on all its inputs. This should lead to improved milage, better drivability etc. I've found the Audi system to work better than the Acura so far. The transmission is better integrated with the engine management to make shifts appropriate and smooth. My main beef with the acura transmission is bumpy upshifts at part throttle on slight declines. This causes the car to lurch and even accellerate slightly. With the ECU knowing exactly what's going on and under full control there's no reason they can't make these shifts smoother. Guess there's still some bugs to work out.

BTW 'drive by wire' could apply to more components like steering etc. but I think the RL only has the throttle that way.

Tully44

I had a similar problem a couple months after getting my RL. When I took the car in for its next LOF, I asked the dealer to investigate. A service technician experienced the lag (actually, more like a cough) but couldn't determine the cause or solution (the cough intermittently occured when cruising at 10-15 MPH and then upon hard acceleration, the car would cough before engaging).

I was initially told to trying different gasloine. I didn't buy that 'solution' and asked the service manager to contact Acura hq. They recommended a part of the computer system be replaced. It took three days for the part to come in but it was replaced and all is good.

SodaLuvr

Sounds software related to me.

If you're capable of, disconnect the negative battery cable when you arrive home from work. Prior to going to work the following morning, reconnect the cable.

This will reset the shift characteristics of the transmission and has worked for me in many cases.

bluemule

1hot nsx is right about the paddles...after using manual for awhile, I've found manual mode to be a great option and convenience. In the situation you've mentioned, manual mode completely eliminates any hesitation/surge caused by the automatic transmission, especially where you're not in control of your acceleration due to traffic and have to back out pretty quickly and then immediately get back to speed. The trick is keeping the revs up in a useful range...which for me with my driving habits is something over 3000/3500/4000. I had to experiment and practice a little before I began to be comfortable with the paddles/gear knob...it's been a long time since I used a clutch in an automobile, but still found the paddles/gear to be somewhat foreign until I used them a little while...and I'm still learning.

For my particular driving habits, I've found 3rd to be a very useful gear for ramps, and I know from prior experience (not on ramps, certainly) that 3rd will get over 100mph before it redlines...(heh).

Fred

KHC

Tully

Was this just the service bulletin update for the transmission? If not, I think I will pursue this further. BTW, my car would not only do this at speeds of 10-15, but also at speeds of 60-70 mph. Thanks.

Kurtis

dadcat1

It is not BS. The Honda/Acura automatic transmission does not contain any planetary gearsets or bands, unlike all other automatics. It uses clutch packs instead. It is essentially a robotized manual gearbox based on the Honda motorcycle manual transmission design with a torque converter in the place of a conventional clutch.

mrdeeno

uh,

1) ALL automatic trannies have clutchpacks...so your argument that Honda's tranny has clutchpacks doesn't support anything about Honda's tranny being a "manual" tranny.

2) a "robotized manual gearbox" as you have stated would be an SMG type tranny...a true manual with a hydraulically actuated CLUTCH in place of a torque converter. this is definitely NOT what honda's auto tranny is.

3) ALL automatic trannies have torque converters in place of a clutch. Honda's tranny is not unique in what makes it an automatic tranny.

Honda's contemporary automatic tranny is a tried and true AUTOMATIC automobile tranny...it is not an "automated" manual based on a motorcycle tranny. it may have similar engineering characteristics because of honda's experience with motorcycles, but the automatic tranny is in no way based on a motorcycle transmission. Another analogy could be the S2000 engine. The engine was designed using engineering experience from motorcycle engines which allows it to reliably rev so well and put out power the way it does, but it is not based on any motorcycle engine.

furthermore, Honda has been making automatic auto transmissions for a very long time, so the reason that the RL's tranny behaves like described above has absolutely nothing to do with Honda being "used" to designing motorcycle trannies.

and therefore, the my conclusion still stands that the mechanic's excuse for the problem is complete

dadcat1

mrdeeno:
I was just using the quote from the following link:
http://www.answers.com/topic/automatic-transmissions
"Automatic transmission families are usually based on Ravigneaux, Lepelletier, or Simpson planetary gearsets. Each uses some arrangement of one or two central sun gears, and a ring gear, with differing arrangements of planet gears that surround the sun and mesh with the ring. An exception to this is the Honda automatic transmission, which does not contain any planetary gearsets; It is essentially a robotized manual gearbox with a torque converter in the place of a conventional clutch."

If you had ever driven an older ('80's) Honda automatic (ATX), you would have realized the performance difference between a conventional ATX and Honda's. The shift from neutral to D or R was nearly instantaneous and the shifting between gears was rather harsh compared to a conventional ATX. Only in the '90's, with the use of electronic controls was the harsh shifting softened with gradual application of the clutch packs.

mrdeeno

dude, this website pulls its info from wikipedia...the leading USER contributed encyclopedia, so I'd take any information from there with a big-ass salt shaker.

especially the expression "robotized manaul gearbox" which is simply wrong when applied to honda's auto-tranny.

but anyway, the excuse given by the mechanic is still COMPLETE for many reasons.

jkanon

Do you have the parts # on this ?