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prius hybrid surging.

Created January 1, 2006, at 2:24 pm by Anonymous

I have a 05 prius and have noticed lately that under full acceleration to pass or enter hiway speeds the car seems to surge and pulse. Like it is lurching and then cutting back on power, almost like it has a govener. Anyone else have the problemM

Anonymous

5 years ago

I have a 2001 Prius with ~75000 miles on it. It has had a similar problem with surging at freeway speeds. It also has had a lag problem which happens when I am on the freeway and the speed drops unexpectedly and simultaneously, the engine loses power. Toyota could not duplicate the problem when I took it in. This past Friday, every major light went on and it had a major power loss. Currently at the dealer awaiting diagnostics. I am awaiting a damage report.

Anonymous

5 years ago

When the rare computer glitch came out I read through some of the DOT reports. Although the Prius is an astonishingly reliable car, it appears when there are problems they are not fun.
There is also the system that protects the electrical motor/generator from overspeed, the TRAC system and the Stability program. Some times I read of instances that really describe the vehicle behaving as it was designed but differently than what most people would expect. The gas engine doesn't 'wind out' when you'd expect and the electric motor 'loses power' on occasion when 'spinning out' (broken pavement and loose material like sand accumulated from the winter will do it).
I've simply become used to the way my car behaves and drive it accordingly. The CV Transmission and the refusal of Toyota to bring to market a 'plug in' hybrid at this time were 'as they say' an attempt to make the hybrid simple so people would 'just drive it'. I guess they didn't quite succeed on this account and maybe should have just built it for geeks.
I wonder if anybody who purchased an older Honda Civic Hybrid with a manual transmission has any experience in this regard? They should have had more of a feel for the dynamics of dual motive power.

Anonymous

5 years ago

Although I own a 2004 HCH w/CVT, other than the engine "auto-stop" and a slight lag in acceleration, there isn't much of a noticable difference.

I've become used to the HCH's IMA system just like you in your Prius' HSD, but I drive to optimize fuel efficiency and to "time" traffic lights.

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Junior Member

5 years ago

My 2001 Prius (71,000 miles) was surging and fading in city traffic just before the warning light came on. The information panel icon, a vehicle outline with exclamation mark, lit up.

I had the car towed to the dealer, who diagnosed the problem as a faulty fuel pedal relay.

The fuel pedal relay was replaced--to the tune of over $600 dollars--and the problem now seems resolved.

The shop gave me the bad part and, as I look at it, I can't see anything that seems to be exceptionally delicate or electronic. It seems to be a mechanical part. Why would this kind of part fail? How common is a failure of this part?

I want to know how many other Prius owners have experienced this difficulty, diagnosis and fix.

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Junior Member

4 years ago

I'm so relieved to see this thread; it means I'm not crazy! Today I took my '05Prius (30K miles) to the dealer for the second time in two years because of this random surge problem. Once again the service mgr told me there's no physical way the car could surge/accelerate as I described - he's positive that the floor mat gets in the way of the gas pedal. I know the floor mat is not the issue - and now I can show the service department this thread. In my case the car surged ("self-accelerated") four times in the two years I've owned it - several times as I sped up to pass another vehicle at highway speed and once as I pulled away from a stop sign. (It actually feels as though the cruise control acceleration feature is somehow engaging.) The surge cuts off only when I hit the brake a couple of times....very scary. I regard this random surge problem as a definite life safety issue - we'll see if replacing the fuel pedal relay does the trick. Otherwise, the Prius is a great little car....my husband has an '06 Prius and so far has not encountered this problem.

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Member

4 years ago

I have a 2001 Prius and have noticed two slightly detectable behaviors. The first is on rare occasion the engine seems to be close to stalling when coasting down from a sustained cruise. This stops once the engine shuts down or I start moving again. The second is while cuising on the interstate at around 65 mph, there is a definite, but transient, reduction in speed for a couple of seconds. Neither one of these caused much concern, since they were just at the edge of noticing and were very rare (5 times in 6 years of driving).

A month ago I was cruising on the interstate to work when the power dropped down considerably and the Engine Check Light, and "!" in the triangle came on. Limped (at idle speed) to the dealer, got the Accelerometer pedal replaced and the car was fixed. Took the Accelerometer home to see that it is just a dual potentiometer (i.e. two independent variable resistors in one housing). I checked the potentiometer and did not fine anything obvious but did notice that at the low end of acceleration setting, there was a mismatch in resistance (500 vs 810 Ohms).

I do not know if the previous surge behaviors were linked to the Accelerometer potentiometers but I have not noticed them at all since the replacement. Time will tell.

Please keep in mind that the repair technicians were directed by the hybrid control unit to replace the accelerometer since the fault detection locks in the trouble part identification. The surging problem could be very hard for the repair technician to reproduce if it is cause by the accelerometer being in a certain position when it occurs.

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Junior Member

4 years ago

On a few occasions, I've also noticed momentary drops of power, mostly while cruising at freeway speeds. Yesterday, the console lit up and the power dropped off. I limped off the freeway and had the car towed to the dealer. They diagnosed a faulty accelerator pedal assembly. I assume that is what others on this thread refer to as the fuel pedal relay. The engine check code was "PS main battery". I believe the PS stands for power steering. The dealer said the relevant code in the computer was "P0300 random misfire" and could be caused by a faulty accelerator pedal assembly or bad fuel injectors (or both), but the technician was strongly leaning toward the pedal assembly. They're not inexpensive to fix ($750)! Like FL_Prius_Driver, time will tell. If I have further problems, I'll post an addendum.

Ioana

3 years ago

I have the P0300 code on my prius and the dealer just replaced the spark plugs and it went away.

vernier

3 years ago

On a trip from San Diego in our nearly new 2008 Prius, we were in heavy traffic on Interstate 5 near Stockton, CA, when the low fuel alarm sounded. Within a minute, we abruptly lost siginificant power and the hybrid alarm sounded and lit, but we were able to maneuver over three lanes to an immediate Stockton exit and a very near gas station. After refueling, 10.6 gallons, the Prious started normally and we finished our trip without further problems. No related problems since.
Reading all the posts on the Internet regarding power loss would lead one to believe that this problem has been solved prior to the 2008 models. I am just letting all know and trying to get my thoughts together before going to the dealer. Any comments?

Anonymous

3 years ago

My '01 Prius was just serviced, tuned up. Well, like the other entries it suddenly lost power. all the triangle icons with exclamation marks came on. I had to have it towed to a dealership. Waiting till Monday to find out what's wrong.

Jan

1 year ago

I have a 05 Prius that I love but when I have the car in park but running and the gas motor kicks in, the car will actually move forward. I've had to keep my foot on the brake when parked! Has anyone had this problem and if I took the car to the dealer, should I insist on a replacement of the fuel pedal relay? Thanks for any insight.

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Senior Member

1 year ago

If the car is "truely" in PARK, it CANNOT MOVE. The transmission locks. If the car is moving forward, there is something wrong with the transmission, it is NOT actually in the "park" mode. No matter what the display on the dashboard says.

Test this by having the car rolling forward VERY slowly. Just barely creeping. then hit "park" button.

Car should stop moving and STAY stopped. If the car moves, the transmission is NOT in "park".

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Senior Member

1 year ago

I've had a similar problem to Jan.

Every time it happened, I thought I was in park, but I had it in drive with the parking break on.

Cera

1 year ago

Jan, I have a regional service manager from my local toyota dealership meeting with me next Tuesday to discuss this very problem. When in park and the gas motor kicks in, my car lunges forward. The same thing happens if I am driving and stopped in traffic. I don't keep my foot on the brake really hard the whole time; I let off a bit while sitting there. If the gas motor kicks in, my car will surge forward and I have to press my foot down hard to get it to stop.

Glad I am not the only one.

dv

1 year ago

that is just the gas motor kicking in with the electric motor. I have an 08 and it does the same. and you know what IT IS NOT THAT BAD!!!! God the people that all they do is complain about the prius are killing me. just trade the thing in if you dont like it. The lunge forward is nothing, the car barely moves. I dont know about you but gas prices are going up again and i am getting 53 mpg.

God just suck it up and quit complaining.

Linda Scott

1 year ago

I was stopped in a long long queue at a red light when this happened. I wasn't looking up, and my car plowed into the car in front of me. THis caught me by surprise, and I couldn't understand how this had happened - I was braking the whole time! Now I'm paying higher insurance costs for 3 years because of the claim. I would like to share responsibility for this accident w/ the design of my car, and think a warning that this could happen would not have been out of place.

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