RAV4 Transmission Behavior Problem
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From: Jeff Strickland on 25 Jun 2007 19:27 "C. E. White" <cewhite3(a)removemindspring.com> wrote in message news:467fdabd$1(a)kcnews01... > > "Jeff Strickland" <crwlr(a)verizon.net> wrote in message > news:EyQfi.679$w2.415(a)trnddc01... >> The Cruise reacts differently than your foot. Since it takes a bit longer >> to realize the changing conditions, it has to apply more gas to get the >> Set Speed back, and this makes a downshift out of OD. The speed returns >> and the shift back OD but the car can't keep the speed because the gear >> is wrong, so it downshifts out of OD again, and the process repeats. >> >> You can take control by shifting out of OD until you get to the top of >> the hill. >> >> The Cruise does not apply small amounts of gas as you do with your foot. >> It likes to apply full gas when if needs gas, and that causes a >> downshift. > > Thanks for the reply. I understand what you are saying, but the behavior > is not normal (at least in my opinion). I am not talking about significant > grades, just minor ones (like on I-40 from Raleigh to Wilmington NC). I've > driven the same route in multiple vehicles and never had one react like > the RAV4. I am thinking the control program is bad. The PCM actually > controls the throttle position and the transmission gear selection. But the throttle position given by your foot changes more gradually and starts sooner before speed has been scrubbed off, so the application of fuel is not as abrupt as it is with the Cruise. The Cruise is delayed, and it tries to give all of the fuel it can, therefore when it finally kicks in, the downshift is needed. Since I'm not in the car with you, it is difficult to tell what you are experiencing, but my instinct is that you are describing normal operation. When the car downshifts out of OD, then press the button to hold it there until you get over the hill. You _might_ be able to see if the linkage on the cruise is tight enough. This might improve the throttle response so that it looks to the rest of the car to be more like your foot. It sure seem like it could do a better > job of controlling the situation. I was hoping there was a PCM code update > that would fix this. My SO won't use the Cruise Control in may cases > because it works so poorly. I have encouraged her to take it to the > dealer, but she thinks that would be a waste of time. If my Ford acted > like her RAV4, it would be at the dealer today. There is no way I would > put up with the behavior (but then I would never have been satisfied with > a I-4 RAV4). > > Ed
From: Tomes on 25 Jun 2007 21:24 "Hachiroku ????" <Trueno(a)AE86.gts> wrote in message news:kwUfi.1908$t95.1794(a)trndny01... > On Mon, 25 Jun 2007 11:48:23 -0700, Ed White wrote: > >> The big difference >> between my driving and the SO's is speed - I usually drive 5 to 10 mph >> faster than she does on the open road. > > > Yup...that'll do it. Tell her to SPEED UP!!! ;) > I agree with this. In our Sienna I often do not use the CC because it annoys me because it is more reactive and I drive more proactive with regard to speed. Tomes
From: Ph on 27 Jun 2007 09:19
C. E. White wrote: > Vehicle - 2007 RAV4 FWD (2WD) 4 cylinder, automatic. > Problem - When the cruise control is used, the transmission > downshifts/upshifts frequently when small inclines are encountered. If > the cruise control is not used, the transmission does not shift in the > same manner on the same inclines - in other words - if you maintain > speed manually, the transmission does not hunt back and forth on minor > inclines, but it does do this if the cruise control is used. Seems > weird, but the behavior is so annoying my SO won't use the cruise > control in many situations. > > Ed > > Are there any service lights illuminated? Scan the computer for intermittent failures. What speed are you trying to maintain when you notice the shifting? Is the vehicle covered under warranty? You may have a vehicle speed sensor malfunctioning or it's associated circuitry. The car is CAN compliant but the ECM controls the CC. It is a 4 cylinder so like others mentioned the torque is substantially less than the 6 cylinder. Small inclines should not make the transmission shift abnormally. |