2003 tl-s

I picked up my 2003 TL-Type S about 2 months ago and from day 1, I have noticed a strange transmission problem. Almost every day, there is a somewhat harsh shift right about 70 mph. It is almost always at the same spot, at the bottom of a 2 mile downhill section of the freeway with my foot just lightly on the gas. Engine is usually right around 2,000 rpm. I can't tell if the engine is shifting from 5th to 4th at this point, because the rpms don't jump up noticeably. But there is a definite jolt through the powertrain (especially since I am always looking out for it).

By the way, my TL is NOT qualified for the extended transmission warranty - it was built later in the model year and supposedly has the "new and improved" transmission. Given all the transmission problems out there, I am worried that Acura hasn't fixed the problems. Any one out there with very new 2003 TL's that have had this problem? For those that had transmission problems, does this sound familiar?

this is me

this might explains it.
Quick downshifts. The transmission has a computerized control system called grade logic. When going down a hill, even a light touch of the brake pedal can cause grade lobic to downshift to the next lower gear. Downshifting helps to slow the vehicle through engine braking.

2003 tl-s

I am familiar with grade logic, but I am pretty sure that I don't even touch the brakes when this harsh shift occurs. However, I did find this FAQ for the CL taken from acura-cl.com

http://www.geocities.com/~gamesmgr/c...ura/#Driving17

"Q: Why does the transmission jerk sometimes when you let off the gas?

A: The jerking you are feeling is most probably the lock-up torque converter in the tranny intermitently locking and unlocking especially at 40 mph+ cruise. Almost every auto tranny since the mid 90's has a form of this. In our car the gear ratios are quite tall in the upper gears. This combined with the "Grade Logic" learning computer control we have, will either lock up and save gas at low load, or if your going downhill your car will know it and not go into overdrive thus creating "Engine Braking" (kind of like when you downshift a manual tranny to brake.) Sometimes when you drive iratically (gunning to 50 mph and then coasting) like myself, the tranny is going WTF and can't decide what it is you want from it. This is part of the "Manu-Matic" part of our tranny."

Don't know if this is true or not, but sounds plausible. Any one else have other ideas?

Comet2404

Yes, I noticed the same thing in my '99, although not so extream as you describe it, and in my old infiniti.... i dont think it is anything to worry about, and remember you do have a 50K warranty, so if anything does occur, then it should happen before that is over with!

-Ryan
'99 SSM TL

ElegantTL-S

How hard is this shift?

It can be the torque converter.

I have not run into this harsh shift at 70+ MPH before. I do have a similiar area on the FWY, somewhat of a downhill. And my car downshifts, but that is because I'm on the brakes, You say you're not on the brakes.

2003 tl-s

The shift is not a a true jolt or anything scary, but it is hard enough to be felt by me, the driver, and be annoying. Anyone else in the car not paying attention probably wouldn't notice it. I definitely am not touching the brakes when this happens. I did an experiment today. Instead of leaving it in D5, I switched over to the manual shift gate and left it in "5." The car couldn't downshift and thus, no problems.

ElegantTL-S

Hmmmm, If it doesn't do it in sportshift mode, then I still say it's Grade Logic working.

2003 tl-s

Well, I guess it is just the Grade Logic kicking in. Thanks for the input!