2001 momentary loss of power

Fuel tank level?

If good, I suggest you visit your Toyota dealer so that the diagnostic codes can be read.

 

There is a possibility that the potentiometer on your gas pedal is starting to go bad. Do a search on this site to get the rebuild procedures. Hopefully, one of the experts on this problem will chime in.

 

Welcome to PriusChat, finco the 1st time poster.

Unfortunately, tangible problems caused by the accelerator pedal do not always set codes. Neither are they rare. Bob Wilson who posts here offers a rebuilding service, but we would want to eliminate other possibilities before sending him money

Just about any other Prius problem *will* set codes, so a Toyota scan remains a good next step. Bring them a bag of cookies and see if you can get it done for free.

Post updates.

 

There are many possible causes. My recommendation is to see if Toyota will do a diagnostic read out of all ECU codes and sub-codes. If you can, find out if they'll also read out all battery module voltages (might as well if it doesn't cost any more.) Certainly share the Toyota recommendations but bring them here since the folks have figured out a few clues. But let's start with diagnosis before going nuts on repair actions.

One quick question, how would you rate your technical skills? Change your own oil and air filters? Major car repairs like engine rebuild? Pretty much take it to a mechanic? It is mostly a question so we'll not go too technical nor too simplistic in our explanations.

GOOD LUCK and come back!

Bob Wilson

 

Excellent! We often have 'hit and run' posters and I'm happy to see your note.

I'd expect to pay ~$100 to get a good diagnostic read-out and be sure to ask for hard copy of the codes and read outs. Try to get a battery module voltage read out too (it doesn't hurt to ask<grins>.)

The ambiguity group for 'momentary loss of power' is huge ranging from:

• loose connector(s)
• sticky parts like throttle plate and others
• failing ignition (spark plug system)
• other stuff that happens

But the beauty of our Prius are the diagnostic codes recorded in the hybrid, engine and battery ECUs (and the others including brake, body, e.t.c.) With the codes and sub-codes, the service technician can come back with a likely diagnosis. Just ask them to hold off on any expensive repairs until you get a chance to "... talk with my brain trust ... " (that be all of us <grins>.)

Call the day before for an early morning appointment and bring a good book or something to enjoy.

GOOD LUCK!
Bob Wilson

 

Yes, a spark plug problem should manifest itself with an engine misfire and the check engine light should come on.

For fun, I suggest that when the car is IG-OFF, you fully depress and release the accelerator pedal around 30x. The point of doing that is to clean the two variable resistors that are actuated when you depress the pedal. See if that temporarily relieves the driveability symptoms that you note.

If yes, then you will know that the accelerator pedal assembly needs to be replaced.

 

Finco if you don't mind bending like a pretzel, here is an even better way to carry out Patrick's suggestion. Get your face down into the footwell, right near the accel pedal. Attached to its assembly right next to the cable connector is a lighter-gray-colored piece of plastic, shaped something like a "D". Press somewhat hard on the middle of that D with your thumb while 'exercising the pedal'. You will be causing the potentiometer wipers into better contact with the..um..things they are supposed to contact by doing this.

Oh, and no time/money for a proper Toyota code scan? Go to your local auto parts chain and see what they can pick up with a free scan. It will be incomplete, no subcodes, but better than nothing.

 

Another, part to check is the throttle plate. There is also throttle sensor that can go marginal. However, sticky throttle plates tend to show up as starting problems.

Bob Wilson

 

I've experienced the same problem with temporary loss of power. Have had check engine come on three times over past 6 months. FIrst visit to Toyota (Lia, in Schenectady, NY) was unsatisfactory--they could not fiugre out the problem. Second visit to Toyota (Romano, in E. Syracuse, NY) yielded code P 420 code, leading to diagnosis of catalytic converter malfunction. Estimate to replace: a mere $2,025!
My trusted auto mechanic says the loss in power could be related to cat, converter problems. Or not. It's hard to say. My gas mileage has been decreasing, avg = 35-40 mpg December - February, compared with 40 - 44 mpg July - November '09, so I suspect something is not quite right.
Don H

 

If you check on other threads, you can get after market cats much less expensively. They may not last as long as the OEM, but will the car?