Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2001 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl contact owns a 2001 Toyota Prius. While driving between 65-70 MPH, the vehicle did not respond when the accelerator pedal was depressed. All of the instrument panel indicators illuminated and the engine suddenly stalled. The vehicle coasted to the side of the road and the engine failed to restart. While the gear shifter was placed in park, the vehicle accelerated unexpectedly and crashed into a guardrail. The driver sustained a whiplash and a police report was filed. The vehicle sustained severe damage and was towed to an authorized dealer. The vehicle was repaired for body structure damages. The technician performed diagnostic tests, but was unable to duplicate the failures. The vehicle was taken back to the authorized dealer on five separate occasions for identical failures, but there were no resolutions. The failure mileage was 42,000 and current mileage was 68,000.
Tl* the contact owns a 2001 Toyota Prius. While driving 20 MPH, the vehicle lost complete power and braking ability without warning. As a result, the contact drove over the median aand crashed into a pole. The air bags deployed. A police report was filed. There were no injuries. The vehicle was towed to the local dealer (titus-will Toyota, 3506 s sprague ave, tacoma, wa 98409). The vehicle was not declared destroyed. The manufacturer was not contacted. The failure mileage and VIN were unknown.
Problems started in November 2003. Had oil changed and an hour later all the warning lights came on in the vehicle. Immediately returned to the dealership where it took 2 weeks to replace the fuel pump (37,000 miles). Since then the car has been back to the dealership an additional 9 times to the current date (May 2005) for several different things. The computer has been replaced two times. The engine has been replaced. The injectors cleaned, then a few months later had to be completely replaced. The throttle body has been replaced. I have been driving the car when it would not acelerate and had to pull over in traffic. The first time the dealership said there were no warning lights when the car got to the dealership and they could not recreate the codes or situation so they could not do anything. …
Twice now I have had warning lights appear on my 2001 Toyota Prius screen. The first time was three weeks ago while I was driving on a freeway in hot weather. I pulled over as I was losing power. The gas engine would not turn on. I was on battery power only. I limped to an exit and parked the car. I had the car towed to the nearest Toyota dealer. He fixed a steering recall part and thought it might be the problem. He could find no error codes. I drove off. Yesterday it happened again under the same conditions. I pulled over, waited twenty minutes and started the car again. The warning lights were then off and the power was now normal. I immediately took it to my home dealer. He tested it and today told me that he could find nothing. He said that if he could not recreate the problem in the shop, there was nothing he could do. …
If the Prius engine does not start immediately when the computer tells it to, the computer stops trying to start it and leaves you with only the battery power...very dangerous when this happens in fast traffic or on an on-ramp. It can be restarted if one pulls off the road and shuts off the car and restarts it. After numerous incidents and attempts to determine the reason for the occasional non-starts, it turned out that the air intake flap in the engine can get dirty and stick, which causes the engine to sometimes take several tries to restart. …
2001 Toyota Prius sudden loss of power at highway speeds three incidents late aug 2006 first week oct 2006 second week oct 2006 in all cases vehicle will not start for 15 minutes but then runs normally. Brought to dealer after first incident and they completed a recall replacement of crankshaft position sensor. Brought to dealer after third incident they have been unable to diagnoses problem or reproduce after 90 miles test driving. Call to Toyota customer service line revealed Toyota has no central point to collect vehicle safety problems when specifically asked if Toyota was interested in discovering the safety problem in my vehicle, the answer was "no" I have been reassured by Toyota that the crankshaft position sensor replacement was performed properly there is no software problem with 2001 Prius similar to the 2004 Prius problem which resulted kin sudden loss of power and lead to …
Engine stalling occurring randomly while cruising at highway speed between approx. 54 to 64 MPH causing vehicle to slow down on the freeway. This problem is potentially hazardous because engine stalls at freeway speed which could result in rear end crash from on-coming vehicles traveling behind at freeway speeds --- furthermore the vehicle must be stopped at the freeway edge to be restarted before problem is corrected. Restarting vehicle immediately corrects problem. However, this problem should be made a mandatory recall item. [Prius scanner shows DTC code p1120 for accelerator pedal assembly problem and there is a manufacturer TSB concerning this problem (TSB eg018-02)]. This vehicle has had the crankshaft sensor replaced pursuant to the recent recall notice and the crankshaft sensor had been leaking oil prior to replacement. …
My 2001 Prius has always been stalling (at least 30 times), usually upon startup, (and especially in hot weather when ac is on at startup) but on 4 occasions, stalls occurred during critical driving in dangerous areas resulting in total power loss and near death experiences. I informed Toyota president watanabe, and they recalled for the "crankshaft position sensor", to fix the stalling problem, but it obviously didn't fix situation because car is still stalling. Dealer is beyond ignorant and clueless and no longer worth talking to, as they are as informed as a rock on a cliff. I am wondering if dealer even performed the recall fix properly. Would like a trustworthy Toyota technician from Japan's tmc (a japanese person) to personally inspect my car.
Tl contact owned a 2001 Toyota Prius. The contact was driving approximately 30 MPH on normal road conditions. The "hybrid" (exclamation mark) warning indicator illuminated on the instrument panel. Immediately, the engine stalled. The warning light remained illuminated until the engine was turned off. The identical failures occurred on twenty separate occasions. The vehicle was towed to an authorized dealer for diagnostic testing. The engine started and resumed normal operation. The failure mileage was 16,000. The contact no longer owned the vehicle. Updated 4/5/10 the consumer has since sold the vehicle. Updatd 06/14/10.
My 2001 Prius has been in for cpu replacements 4 times and a engine rebuild @ 69000 miles for the problem this site mentioned in the news about the 04-05 Prius stalling. They said it was low compression on the last service call. Well the problem is back!! Even after a rebuild. So now what? Oh and what is worst is that I have to take a photo of the problem lights because when the problem happens it produces no codes?!?! So they charged me $75 and did nothing once. Nice service. Where I take my Prius: fox Toyota-Scion 415 taunton avenue east providence, ri 02914 phone [phone] , fax [phone]
Related recalls
Engine and engine cooling
On certain passenger vehicles, due to improper molding of the resin body of the crankshaft position senor installed on the engine block, engine oil May penetrate the seal and enter the sensor wiring connector. The wire harness connector May not be sufficiently attached to the locking tab of the sensor wiring connector.
Remedy: Dealers will replace the crankshaft position sensor free of charge. The recall began on July 26, 2006. Owners May contact Toyota at 1-800-331-4331.
Engine complaints in other Prius years
Frequently asked questions
How common are engine problems on the 2001 Toyota Prius?
NHTSA has 20 complaints about the engine & cooling of the 2001 Toyota Prius, 12% of the model year's 165 complaints. The component named most often is engine (4 mentions).
Is there a recall for 2001 Toyota Prius engine problems?
Yes — NHTSA recall 06V-266 (engine and engine cooling, Jul 19, 2006). Recall repairs are free at authorized dealers.
At what mileage do 2001 Toyota Prius engine problems start?
Half of the complaints with a recorded mileage happened before about 40,000 miles, and 7% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 1 injury to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.