Driving home at night on the 405 freeway at approx. 65mph, suddenly all the dash warning lights illuminated, including the mil symbol, along with a warning symbol on the navigation screen. I pulled off the freeway and parked at the curb. After checking the owners manual, I slowly drove the rest of the way home on surface streets. The next morning (monday) I drove my car to miller toyota in culver city. The primary diagnosis was failure of the inverter coolant pump, which was replaced under the terms of my toyota platinum extended warranty. However, upon further research, I discovered that toyota had issued a technical service bulletin (tsb) covering this very part, on january 26, 2007, indicating that they were aware of this failure-prone part, and that an "improved" replacement assembly was now available to address the issue. In addition, replacement would be covered under their 5-year/60,000 mile toyota powertrain warranty. Approximately one month later, on may 15, 2010, while driving my father's 2004 prius to have new tires installed, the same sequence of events occurred. I immediately drove the vehicle to the nearest dealer, santa monica toyota, where it was diagnosed with the same failure code, p0a93 (inverter cooling system performance). Although the vehicle had only 34,242 miles on it, it was not covered under the powertrain warranty, as the time limit of 60 months had expired. No amount of discussion with the dealer or toyota's customer experience center could convince them that this part should be considered part of the hybrid system, and as such be covered under their 7-year/100,000 hybrid warranty (despite it being named the hybrid inverter coolant pump). On-line prius-related chat rooms are full of identical situations involving this part. Clearly, toyota knows this part is prone to premature failure, but continues to treat it as a "secret warranty" item in order to avoid having to issue a formal recall.
2004 Toyota Prius engine complaints
Page 2 of 4: complaints 11 to 40 of 98, newest first, as owners wrote them.
Failure of inverter coolant pump occurred without warning during normal driving conditions. This is apparently a common problem occurring at many different mileage intervals for other owners. Immediate significant loss of power and several warning lights illuminated. Cruise control and A/C went offline. Requires replacement which in this instance was $605.00.
Tl*the contact owns a 2004 toyota prius hybrid. While driving approximately 60 MPH, the check engine warning light, and an unknown warning light illuminated on the instrument panel. The dealer was notified and advised the vehicle was safe to drive; unless the temperature, brake or oil warning lights illuminated. The vehicle began to lose power and the anti-lock brake system warning light illuminated. The vehicle was maneuvered to the side of the highway. The vehicle was towed to the dealer. The failures were related to the inverter water pump and the skid control electronic control unit (ecu). The inverter water pump was replaced. The failure occurred a second time. The vehicle was repaired for the malfunction. The failure and current mileages were 61,000.
We own a 2004 toyota prius. On 02/18/2010 it lost power on the road, major malfunction lights came on, among others, and had to be towed to the toyota dealer in carlsbad, ca. After diagnosing the problem, they said the computer had failed and needed to be replaced. When the computer was replaced it started transmitting new problem codes, namely, poa94, poa78, po279, and po555, which meant that the transaxle had failed, and computer codes show that the inverter could fail also. Total repair cost: $5,594.00 so far. If the inverter fails, it would be a total of $9,843.00 to repair. I don't see who would pay this exorbitant amount, let alone being able to afford it. The same incident occurred on 09/15/2008. The prius had lost power and we took it in to the dealer. They performed a diagnostics test, test drove the vehicle on the freeway for 9 miles, it ran o.k. And no computer trouble codes were found at the time. This sounds like it was a prelude to the vehicle failure were are experiencing today, and we are suspecting it has to do with the electronic system. As it stands now, the prius is sitting at the toyota dealer. They had removed the new computer in light of the fact that the entire vehicle is totaled. In short, the prius was fine one day and totaled the next. They told me that this doesn't happen very often. Please let us know what we can do to resolve this problem. Thank you.
On 23 jan 2010, while driving I-85n in the south carolina mountains the car stalled at 70mph. An audible alert sounded, the car jerked and three warning lights went off. I coasted the car to the shoulder and shut the car down. I restarted the car -- the warning lights cleared -- and continued driving. About 30 minutes later, still in the mountains, the same things occurred (stall while driving 70mph on the interstate.) when I restarted the car a yellow "!" warning remained on. I continued the trip to virginia with no further problems. The warning light went out. On 5 feb 2010, while driving on I-95s in the south carolina mountains the car stalled, warning lights and audible alarm sounded. Upon restart the "!" stayed on. This happened two more times; once on I-95 and once on I-20. The last two times the red triangle warning light stayed on also. On 6 feb 2010, I took the car to toyota center in columbia sc. The service manager told me the water pump needed to be replaced ($384) because air got into the system. I asked if that was why I could hear "sloshing" from the engine when driving; he said yes. I explained that I was confused since the coolant recovery tank never went below the low line. His response was that air in the system was a known problem for the prius and that I should keep the coolant level higher than marked. Also that driving in the south carolina mountains -- both the heat of the engine and the angle of ascent and descent -- is probably what triggered the problem. Prior to both trips, the car was checked by a mechanic. Fluid levels were clear and adequate. I am now in the flatlands of texas, and I can once again hear the sloshing sound coming from my engine. Beyond the expense I am concerned that the engine is completely stalling. If this were to occur in rush hour in a crowded city I'm not sure the car would be safely navigable to the shoulder.
2004 prius: after driving at 10mph on gravel road with potholes and then turning on to smooth paved road engine speed and speedometer started to vary wildly with speedometer going up to 45mph down and back up again for a 5 minute period while driving on the paved road at about 30mph. This continued but car itself did not accelerate abnormally despite change in engine speed and wild speedometer.
About 40% of the time, my toyota prius doesn't want to stop or slow down when the brakes are applied. Under these conditions, I have to apply the brakes hard and then the car will slow down. It feels like the car wants to "run away" when the brakes are applied. It exhibits this behavior in many circumstances: stopping at a stop light, slowing down on an expressway, or slowing down on a city street. *tr updated 11/23/09 *bf the check engine light illuminated. The passenger front window switch wasn't opening or closing the window unless the master switch was used. The throttle body had to be cleaned. The fan belt and brake light switch were replaced. Updated 11/24/09 updated 01/06/10 *bf updated 01/07/10.
2004 toyota prius. Driving at 70 MPH on I-57 north. While driving the gasoline engine stopped functioning, triggering several warning lights. I pulled the car off to the side of the highway and managed to exit the highway on battery power. There was a recall in 2005 for a similar condition. My prius had the recall work performed in october 2005 for the software problem. The toyota dealer is unable to find any reason for the problem and can not replicate the engine failure. As a result, they will not perform any further investigation or maintenance on the vehicle for this problem. I have a case pending with toyota customer care, but do not expect any further assistance from them. I am also being charged labor for the dealer to inspect the vehicle. There was no fire or property damage, but if I had not been in the right hand lane, I very well could have been in a serious accident. Suddenly loosing power at highway speeds is unacceptable. If they are unable to remedy the situation, I will be returning the vehicle to them.
This happened to me and cost over $700 to fix: failure of inverter/converter coolant pump. Hybrid vehicle has 2nd coolant loop for high voltage inverter/converter. Failure of inverter/converter coolant pump allows inverter coolant temperature to rise well above nominal. At a certain trigger point hybrid control ecu sets a trouble code that immediately disengages operation of inverter/converter (and simultaneously disengages cruise control and A/C, which runs of alternating current produced by inverter). Immediate impact is a sudden loss of vehicle drive power as inverter/converter supplies to electricity to motor generator 2 (mg2) which is directly connected to drive wheels and supplies needed motive force to maintain highway speeds (ice alone is insufficient). Also inverter/converter coolant loop provides cooling for mg2 & mg1. Continued operation of vehicle with failed inverter/converter coolant pump could result in catastrophic failure of main electric drive mg2 and subsequent loss of motive power. Pump failure occurs without warning, although there may be a brief period of intermittent pump operation/non-operation prior to final failure. The failure seems to be the result of either a defective inverter/converter pump ass'y or one insufficiently engineered to withstand continuous operation in such a critical component. Pump failure occurred after approximately 160,000 miles, although has been known to occur in other instances as early as 32,000 miles. Sudden loss of power and disengagement of cruise control at interstate highway speeds could cause driver to lose control or to be unable to safely steer to a safe breakdown lane.
Failure of inverter/converter coolant pump. Hybrid vehicle has 2nd coolant loop for high voltage inverter/converter. Failure of inverter/converter coolant pump allows inverter coolant temperature to rise well above nominal. At a certain trigger point hybrid control ecu sets a trouble code that immediately disengages operation of inverter/converter (and simultaneously disengages cruise control and A/C, which runs of alternating current produced by inverter). Immediate impact is a sudden loss of vehicle drive power as inverter/converter supplies to electricity to motor generator 2 (mg2) which is directly connected to drive wheels and supplies needed motive force to maintain highway speeds (ice alone is insufficient). Also inverter/converter coolant loop provides cooling for mg2 & mg1. Continued operation of vehicle with failed inverter/converter coolant pump could result in catastrophic failure of main electric drive mg2 and subsequent loss of motive power. Pump failure occurs without warning, although there may be a brief period of intermittent pump operation/non-operation prior to final failure. The failure seems to be the result of either a defective inverter/converter pump ass'y or one insufficiently engineered to withstand continuous operation in such a critical component. Pump failure occurred after approximately 160,000 miles, although has been known to occur in other instances as early as 32,000 miles. Sudden loss of power and disengagement of cruise control at interstate highway speeds could cause driver to lose control or to be unable to safely steer to a safe breakdown lane.
2004 prius stalled while driving. Towed to dealer who found no problem.
2004 toyota prius stalling. After speaking w/ the toyota consumer helpline, I've learned that the could put a program in the computer that gives you enough time to pull to the side of the road before you stall. I responded that there isn't always a shoulder to pullover to. I started getting warning lights at 6,500 mi. I now have 36,880 mi. In the beginning, the lights were just a joke or a nuisance when I had to bring it in to the dealer. On nov 11, I stalled along w/ warning lights. You can pull over and shut it off,wait a minute, restart and drive home with warning lights, but they go out when you start up to go to dealer. I brought it to them anyway, but after they looked at the codes I was told it was soft codes and that there was nothing that they could do further. In dec, I got the warning lights, but no stall. I drove to work and back and the lights went out when I started up to go to dealer . Feb 25 6:30 pm in the merge lane of the I-10,where there isn't a shoulder and cars are coming 40 to 50 MPH into the lane to exit. How I didn't get rear-ended, I can't explain. Turned key off, restarted and drove home. Lights went out when it came time to drive to dealer sunday night for them to check out mon am. I'm trying a new dealer thursday and I have contacted toyota consumer line for assistance. I not sure how far anyone can fix this issue. The service dept has updated the computer and has given me a new computer, but they don't have an answer when I inform them that this is getting dangerous, now.
Prius stalled when pulling into traffic from a stop light. All lights on the dash board were illuminated including the check engine light. Only electric drive systems was operational. I immediately pulled into a parking lot and turned the car off. Upon restart, only the check engine light was on. Was able to drive to the dealership 2 miles away. Stored error code p0a7a was identified - bulletin eg029-05. "false m.I.l. "on" condition. An updated control ecu was installed, covered by warranty.
Dt*: the contact stated while driving 30 MPH the vehicle intermittently stalled without warning. This occurred on three occasions. The vehicle was maneuvered off the road and towed to the dealer each time where the problem could not be duplicated.
2004 toyota prius engine stalled while driving. ***no answer required*** *ts the consumer requested reimbursement for the towing expense.
2004 toyota prius cut off while consumer was driving at highway speeds.*mr when the consumers vehicle stalled on the highway, another motorist rear ended the consumers vehicle.
My toyota prius 2004 VIN [xxx] engine suddenly stalled on the freeway. I still can't restart the engine. As of 10/17/05 dealer still can't find the reason. *jb updated 07/18/2012 *js information redacted pursuant to the freedom of information act (foia), 5 u.s.c. 552(b)(6)
I own a 2004 toyota prius purchased on march 2nd 2004. Approximately 4 months after acquiring my vehicle I was merging onto the interstate when I experienced and ice engine failure. All the warning lights came on and I was able to pull to the shoulder of the road using the electric motor. Subsequently I rebooted the car and the engine turned over. The next day I took the prius to a toyota dealership. They had the car for six days and apparently performed diagnostics and performed a software fix. Recently, on september 8th 2005 I experienced a 2nd occurrence of the ice engine shutdown. This scenario occurred while pulling up to a red light. Again all the warning lights came on and the engine shut down. I rebooted the car and took it to the dealership for service. The toyota dealership completed a tsb eg047-04 for recalibrating the engine ecu. Note, I did not receive any prior tsb's from toyota regarding the engine problem.
Toyota prius owned by our agency has had the engine stall problem 3 separate times.
Dt: the caller said while driving at 40 MPH the vehicle stalled. She was able to get off the road. Had to have the vehicle towed to dealer, who did not know yet what the problem was. Manufacturer has not been contacted yet.
I was driving on the highway at between 40-55 when the engine stalled. I tried to restart it, but it would not start. The car had to be towed. There is a one-week wait on its repair. This happened approx. 240 miles from home. This is the second time this has happened. Prius 2004.
Dt: 2004 toyota prius. While driving 55-60 MPH vehicle constantly lost power. The engine check light came on. The consumer had difficulty restarting the vehicle. *ak
Dt: 2004 toyota prius, consumer was driving on highway 24 and the vehicle stopped. It had to be towed. Vehicle lost power while going 60-65 MPH. *ak. The vehicle stall again on august 29th, 2005 while being driven driving 40 MPH. The mileage was 24480. The consumer contact gm and demanded a new vehicle. The manufacturer bought the consumer's vehicle back.
Dt: total breakdown of wife's 2004 prius on september 2 in fine weather one in san jose. The vehicle displayed sudden and significant loss of power while merging into the interstate. Loss of gas/engine power with failure of the internal combustion with engine to start, resulted in only electric motor propulsion and breakdown on the highway as the battery quickly went to single pink bar level within a 1/2 miles. Multiple mil lamps lit up and stayed on. Began to merge onto the highway from a stop speed of 30 or 40 MPH and slowly accelerated into heavy traffic. She had to pull off to the (ugh) breakdown lane of the highway with all of its debris, etc. The dealer completed the repair, san jose invoice number tocs190787 dtd 9/2/05 applied eg047-04 on car. The dealer repairs seemed to have fixed the car. Contacted a toyota prius advisor with three concerns: if there was a service bulletin for this characteristic that would prevent the roadway failure then why was it not executed during prior services 3-9-05, 5-26-05 & 6-09-05 at this same dealer. What LED one to believe that the car was not reliable after this repair. The consumer, an accomplished engineer, a knew about software bugs. A software bug did not impair operation until the right combination of environmental factors was reached. The consumer assumed that all prius had this potential bug that contaminated the electronic control unit (ecu). Ecu.
Per consumer call with c. Rose (odi) on 9/29/05 july 2004: she was backing out of driveway and went from reverse to drive without stepping on brake and started to pull forward and the vehicle stalled/ cut off. Could restart all times. July 6, 2004: stopped at a stop light and started to accelerate to about 10-20 MPH for about 1 minute when the vehicle went into neutral; gas engine stalled, but she had electric power, but said neutral; thinks stepped on brake and pushed power (starter) button 1-2 times and was able to continue driving the vehicle at full speed. July 13, 2005: happened 2 times - driving on a crowded city street at a max of 30 MPH when she noticed that the vehicle would not respond to her stepping on accelerator (panel showed neutral); able to drive vehicle no more than 5-10 MPH. Pulled over immediately less than 1/2 mile. Turned it off and was able to restart right away. Drove for another minute and then the same thing happened again so she pulled over, turn off the vehicle, and restarted it right away. Did not have any additional problems that day. July 23, 2005: on the freeway going to have the vehicle looked at by dealer. She was accelerating from 45 to 65 MPH, when the vehicle lost power. Vehicle continued to decrease speed. She immediately pulled over to the side of the road (believes it got down to no more than 20 MPH). She stepped on brake and restarted. Not sure if the vehicle fully cut off. Brought to the dealer and they could not duplicate what happened or figure out what was wrong. Dealer called toyota to see if this happened before and they said it did not. Dealer did not do any work on it. August 21, 2005: backing out of driveway going from reverse to drive without engaging brake, vehicle stalled/ cut off.
Nothing special or extraordinary LED up to this failure. I was driving to work at about 7:00am. The temperature outside was about 70 degrees and the car is kept in a garage every evening. In the middle of acceleration (I was going about 25mph), the car stalled and the "red triangle of death" came up on the dash, along with several warning lights. The navigation system also provided the word "problem" and a little, red car symbol with an exclamation point in the middle of it when this happened. I was able to drive to an apartment complex under battery power only. I then shut the car off, waited a few seconds, and then started it again. The engine did kick back in after this, but the warning symbol (little, red car) on the navigation system didn't go away. I took the car to my toyota dealership and they said that they had to "recalibrate the engine computer." the car is now running as normal. The car is a 2004 toyota prius. My worry with this is what if this would have happened while driving across kansas, while 80 miles away from anyone to help you? The battery power surely wouldn't be enough to get you to safety. This is a problem inherent in the software of the engine computer and it should be fixed for all owners.
I was transitioning between two freeways in my 2004 toyota prius and had started braking/decelerating for a looming traffic jam up ahead when the gas engine stalled and all dash warning lights came on, along with the nav system screen saying "problem" and a red car icon. My speed could have been anywhere between 70mph and 35mph at the time of the stall. The electric motor was still functional, so I exited the freeway, parked the car, powered it off, then powered it back on. The red triangle of death was still lit on the dash, as well as the engine check light, but the gas engine was now operating normally and was recharging the almost-depleted electric drive battery. I was able to drive home without any further incident. The next day, I took my car into toyota of huntington beach for repair, and they "reprogrammed [the] electronic control module". My symptoms seem related to the pe05029 defect investigation and the federal safety agency odi complaints of other prius drivers. This desperately needs to be a recall item because a sudden deceleration to 40mph on a freely moving freeway with other traffic traveling at 75mph could be a very dangerous rear-end collision risk.
Vehicle stalled while driving approximately 25-30mph on surface street with 1/4 tank of gas remaining.
Dt: vehicle stalled intermittently and lost power. *ak the consumer sold the vehicle back to the dealership.
Driving downhill ~50 MPH when all warning lights came on. Car wouldn't accelerate. Gas engine would not start and battery charge was dropping fast. Limped ~1 mile home at 25 MPH. Turned off car, too late to call toyota that night. Turned car on and gas engine started right up. All warning lights still on, and main battery nearly drained. Slowly drove around on local streets, battery charged. Parked and turned off car. Later in day, turned on car, all warning lights were off. Took it to dealer when we got home. Dealer claimed computer had no record of the problem. Prior to this event, toyota had upgraded the computer software on this car as described in hv ecu software update 00204. We were told this fixed the stalling problem, but obviously does not. Jb
VIN decoder
See the problems and recalls for an exact car
Buying a used 2004 Toyota Prius?
Check the exact car before you pay: accidents, salvage or flood titles, odometer readings and previous owners.
Check its history