I am hoping someone at Toyota can help me with this issue. I have spoken to the tech at HB Toyota and to two members at egroups. One member claims to have the problem solved but did not offer any details as to what the fix was. The other has surges similar to what I am describing.<br><br>Problem -- The car does a very noticable surge at between 69 and 72 mph. Only twice has the surge been enough to reduce the speed on the dash by a visible 1 mph. The feeling is that of a slowing of the car. It lasts from 1/4 to 1 second and repeats itself every 15 to 30 seconds (irregularly) for up to ten miles.<br><br>I've spent a lot of time keeping track of evry aspect of the car when it happens.<br><br>Tank can be full or empty.<br>Speed and trottle are constant on level to a very slight downhill road. (not noticed on uphill grades).<br>The energy screen does not change when it happens.<br>It typically shows ICE to wheels and no charging.<br>Consumptions screen is usually at about 55 to 70 mpg.<br>It happens early in the trip, 3 to 5 minutes from cold start and lasting up to 15 minutes from start.<br><br>I can get it to happen almost every day on my way home from work. It has also happened on several other ocassions when the road grade, speed and run time were similar to my comute home. <br><br>My best description of the feeling is that the motor goes briefly on generator and then back to nuetral - Or there is a brief interuption in the fuel or spark.

I feel the very same surge very noticeably only it's more like the power is retarded for a moment or two rather than surging faster. I notice it especially around 70 MPH for the first about 20 minutes of the drive and while trying to maintain a steady speed. It feels like the computer is confused and doesn't know whether to supply power or not. I also feel it other times but to a very minor degree.<br>I get around it by either going 65 or less, going 75 or more or by applying power steadily or by slowing at a steady rate (usually going up or down a hill). <br>Very noticeable - very annoying, but like the brakes, you get used to it and work around it.<br><br>Jerry

Dave<br><br>Could you contact me by email. I am experiencing surging also but haven't been to the dealer yet. I got my car at South Coast Toyota and received it 11/24. <br><br>My email address is thetollhouse@..., and I live in Westminster.<br><br>Al

&gt; surging... only it's more like the power is retarded <br><br>When my Prius was new, it did the same thing (but only for the first few miles). It was kind of annoying until I realized it's just as annoying as feeling gears shift on any other vehicle and feeling an engine vibrate at the stoplight. Then I discovered it didn't do that when the internal load was different. (My Prius was packed with people & cargo.) So I kind of deducted that it was a normal part of the hybrid system.<br><br>But it wasn't until that post that I realized the power retard (not really surging) has softened. I had to really pay attention today to identify when it was happening.<br><br>JOHN<br><a href=http://home.att.net/~john1701a/ target=new>http://home.att.net/~john1701a/</a>

I experience the mysterious "surging" (more of a feeling of slightly reduced power) phenomenom during my morning commute. It occurs at approximately 65-75 mph and is most noticeable when I relax the pressure on the "gas" pedal. It usually lasts for 1-5 seconds and then the car seems to normalize. It is slightly disconcerting, but it nevers lasts too long and seems to go away after the car is fully warmed up. Anybody out there have any ideas or comments?<br>BTW, my Prius has 4,300 miles on it and it is averaging 48 mpg. Best darn car I've ever owned!<br>YMMV.

Not sure just what is being observed here -- is this the sensation of the "clutch slipping", where the engine seems to race slightly? If so, it's perfectly normal, as it just signifies an adjustment in the way the planetary gearset is combining the rotation of the two motor/generators and the engine. I don't think there is any real loss of power, though it might feel that way because we're used to increased rpm = more power. <br><br>Maybe it occurs most often during warmup because the engine is being used more to charge up the battery?<br><br>-- PeterD

&gt;natsmada asked<br>&lt;surging&gt;<br>&gt;approximately 65-75 mph and is most noticeable <br>&gt;when I relax the pressure on the "gas" pedal. It <br>&gt;usually lasts for 1-5 seconds <br>Ah HA! <br>Were you on a slightly downhill grade at the time?<br><br>My Prius shuts off it's ICE at 65! every day on one particular place on I-287 South: long, gentle downhill grade and I'm usually playing "flea" at the time.<br><br>Durn near pooped my drawers the first time it happened! I noticed IMMEDIATELY when the ICE "died":<br>"Oh NO! It STALLED at 65 in a herd of SUVs! I have NO PS or brakes and I'm gonna get squashed and crash and burn and . . . DUH! It's a Prius.. It's normal!"<br><br>Happend tonite too: was getting 75 MPG for nearly 10 minutes on I-80, thanks to a near gale force tail wind - some of those miles were with ICE off!<br><br>Still freaks me a bit - just ain't "natural" at all - it aint!<br>Bill Powell<br>(Prius: Just Sail It!)

My wife had the same probem with her Prius. When she took it in for the power steering recall to Walnut Creek Toyota, they replaced an ECU which deals with the engine. She has not experienced the surging since.

Can you please describe the surging problem with your Prius? Mine is also surging badly at 70 Mph and I am thinking about taking it to the dealer. If you can provide any details about exactly what was replaced and how your dealer determined the problem it would really help me.<br><br>Thanks<br><br>Allen

Hi Allen,<br><br>My Prius only surged in the mornings when the engine was cold and I was travelling at speeds between 65 and 75 MPH. While my foot was applying constant pressure on the accelerator, the engine would speed up then slow down dramatically. Toyota replaced the ECU with no qualms. In fact, the technician asked if I had noticed the energy screen change between the electric motor and the ICE rapidly - the ECU couldn't decide which engine to use and that was causing the surging. It took him 30 minutes to change out the ECU and 30 minutes for the other computers to become reacquainted with the new ECU then it was ready to come home. We've been watching the gas mileage since and haven't seen any drastic declines because of the new ECU - just my driving habits.<br><br>Hope this helps.<br>Lee's wife

Re: "Still freaks me a bit - just ain't "natural" at all - it aint!"<br><br>Uh oh, Bill's still a newbie. Repeat after me: Burning gas when you don't need to isn't natural!<br><br>Next time you have the misfortune to drive a prior technology car, you'll understand.<br><br>Robert Snyder<br>(Prius: The natural alternative)<br><br>P.S. How come you get tailwinds on I-80, I always seem to get the headwinds!

Hey Bill<br><br>Since when do they have hills in NJ??????????<br><br>Ha Ha

The sensation is with a very steady pedal on a level road, where you would expect nothing to happen. While I first described it as a surge in the original post it is best derscribed as a negative surge. A movement that causes your nose to get closer the the steering wheel. Since the car is getting 55 to 75 mpg when it happens there is no change in the engine noise. This lead me to my original feeling that the Traction Motor momentarily goes to charge mode, decelerating the car and resumes normal opperation.<br><br>ANY THOUGHTS?<br><br>From

&gt;tollhousepop smirked:<br>&gt; Since when do they have hills in NJ??????????<br>We just keep em all hid away from all them durn tourists. Let em smell Newark instead.<br>bp<br>(Prius: Up and Down and All Around.)