2006 Toyota Prius: multiple warning lights

Filed Jan 2, 2025 · Brakes, Electrical · DE

The following describes a near total failure of the brake system that accompanies and is triggered by routine aging of the battery. I believe this applies to multiple model years and editions of the Prius, based on reports by other owners on owners' discussion groups. I believe this should have the highest severity level. Here is what happens: An alarm is sounded, several warning lights ABS, VCS appear, and soon after that, the front brakes stop working. The rear brakes then prove ineffective and lock up. The happens with high frequency under any of the following conditions: (a) as the battery approaches 3yrs age, (b) it is excessively cold outside. (c) there is a higher than typical load on the 12V system from any of a variety of reasons. After installing a fresh new 12V battery, the above happens with much less frequency. There no warning on the dashboard to indicate that the condition of the 12V battery is not safe for operation of the vehicle. It seems clear that the route cause is that the brake control unit is configured within inadequate tolerance for the normal aging of the 12V battery, compounded by the absence of warning on the dash. This probably traces back to a poorly chosen LDO voltage regulator in the design of the brake control unit. Recommendation: Review the electrical designs for the brake control unit, all model years, replace as needed and update the dash board computer to provide warning when the battery condition is not sufficient for safe operation of the vehicle. I further recommend that this be done with all due haste, as the condition is quite dangerous. Qualifications: PhD Chemical Physics and Electrical Engineer

Filed Nov 8, 2019 · Lights · 96,500 miles · CA

The right side head light on my 2006 toyota prius will turn off on its own. It will work again if I shut all the lights off and turn it on again. It doesn't seem to happen while the car is stationary, but will turn off soon after the car starts moving. It doesn't matter if it is on a bumpy road, moving slowly, or on a highway. It will turn off within seconds to several minutes. I took it into the dealership around july 8th, 2019 when I first noticed the problem. They said there was no signs of any damage and said there wasn't anything that needed to be done. Since then I have just been switching the lights off and back on when it happens. But then last night on november 7, 2019 both lights went out while I was driving on a public road. It happened as I accelerated after a full break.thankfully turning the lights off and on again worked. The right side turned back off again that night, but both did not shut off again after the incident.

Filed Aug 5, 2019 · Engine · 95,000 miles · NY

My car overheated suddenly, showed multiple warning lights, and was diagnosed as having a failure of the electric water pump --symptoms exactly identical to those described in !2v536000. My car did not stall but had the secondary conditions shown when toyota engineers tested the likely results of failure of the faulty coil wire.

Filed Jun 26, 2019 · Lights · 81,000 miles · AL

Driving at night all lights go out and the driver cannot see anything. Very dangerious! This happened traveling 60 miles per hour at night.

Filed Aug 7, 2018 · Brakes, Electrical · 180,000 miles · CA

As I was reversing and my foot was on the gas pedal a loud beep came on, all of the dashboard warning lights lit up including the brake light. I checked to see if my parking brake was on and it was not. I put the car on park and turned the car off and on. My car worked I drove a few minutes and as I was approaching the freeway I luckily came to a stop on a red light. Suddenly the same loud beep, warning lights, and break light came on and this time because my foot was on the brake pedal I felt the brake extremely hard/stiff. Because I was at a red light I quickly put my car on park turned the car off and then on again and made a right turn to avoid going on the freeway. I decided to carefully drive to a family member's house close by going no more than 25 MPH with my emergency lights on I did not want to risk my brakes stiffening up and failing but I was in a congested area with no parking. I was fortunate enough not to get on the freeway and I was fortunate enough that this failure happened on occasions where I was either going very slow or already stopped. I don't know what could happen if I had to come to a stop and could not because my brakes were stiff. Toyota will not cover this manufacturers ABS actuator defect that they know about because the deadline was dec. 2017. This is dangerous and can lead to accidents and even death.

Filed Jun 27, 2018 · Brakes · 68,000 miles · FL

Brake actuator failed when car was backing up in a parking lot; car made jerking action and stopped on its own; all warning lights lit; warning to take it for service immediately - which was done after consultation with the dealer (driven there).

Filed Apr 7, 2018 · Brakes · 231,000 miles · FL

Failure of ABS actuator. I received notification of a " warranty enhancement " program that extended the warranty for my vehicle on the brake actuator assembly. The extension portion of the warranty for my vehicle expired on december 31, 2017. I purchased the car new in 2006 and have faithfully had it serviced by the toyota dealership every 5000 miles. Toward the end of 2017 I noticed the car making some noises after I parked it in the garage. I attributed it to the noise that the car often made when first turned off. I had the car in for service at the toyota dealer in oct and nov 2017 and again in jan 2018 and no problem was identified with the actuator. The noise continued and became more noticeable so when I took the car in for its routine service in march 2018 I asked them to check what was causing the noise. When I went to pickup the car they told me they did not hear the noise. When I got back into the car I immediately heard the noise and accompanied them back to the car to hear the noise. The mechanic took the car back to the shop and when he finished I was told it was the brake actuator assembly going bad and was quoted $2700 to have it replaced. I was advised that I would know know when it failed completely when several of the warning lights illuminated. Yesterday while driving 55mph on a 4 lane highway all of the related warning lights came on. Fortunately the brakes still worked and I was able to make it home safely. After exploring the internet I found this is a fairly common dangerous failure and thought it was interesting that toyota has stopped providing replacement when this part fails especially as they are aware of the issue.

Filed Aug 15, 2016 · Electrical, Lights · 85,000 miles · FL

The headlights flicker and then go out. It is necessary to turn off all lights and then turn them back on. The same thing happens after a short period of time. This happens when the car is moving and I have been pulled over because I was unaware that the lights were out while driving in the city.

Filed Dec 11, 2015 · Electrical · 217,385 miles · CA

The car was at a stop light when all the dashboard lights went out (nightime). When I tried to turn the vehicle off, the car would not shut down. This is a known problem to toyota especially on high mileage vehicles. The car has 217,000 miles (original owner). Toyota issued t-sb-0172-09 as a "warranty enhancement program" in order to avoid an official recall of the problem. Unfortunately, I missed the deadline by 3 months.

Filed Jun 12, 2014 · Electrical, Engine · 123,900 miles · CA

This complaint has not been qc'd. The contact submitted an email and requested that the official ivoq be written verbatim to the email. Kmj I have multiple situations with my toyota prius 2006 in the beginning of may 2014 I a loud beeping noise filled the car. The system had multiple lights displaying showing including the emergency brake light ( while I was driving), ABS,vsc, a red triangle with an exclamation point in the middle, etc. As, this was happening car immediately started slowing down and I was forced to pull it to the side of the street. This same thing happened to me three other times while I was on the freeway. One time I was driving home from work and my car again started decelerating while I had multiple cars around me on the freeway. All of the lights were displaying, I put my hazards on and was forced to move to the side of the road while I was almost hit by the car behind me because my car was rapidly slowing down. I took the car to the dealership service center and they didn't know what the problem was. They did a diagnostic test, multiple test drives, but at that time they didn't know. So they told me to drive the car home and come back if it happens again. Within the week I was exiting off of the freeway with my children when I start hearing the loud beeping noise, all the lamp lights came on, and as I am waiting in line to exit the freeway onto a busy street the car stops. I panicked, put on the hazards, the car wouldn't allow me to shift it into drive it had moved to neutral on its own. I turned off the car, turned it back on and was slowly able to move the car. This time I took pictures of the lamp display to show the service members as well. My children, myself, and other drivers could have been seriously hurt! The toyota service center told us we have a bad computer, the problem is with the ecu, and the car went into a fail safe mode.

Filed Mar 19, 2013 · Lights · 87,906 miles · CA

Customer states while driving at night, with low-beams, left light went out. Customer switched to hi-beams and all the headlights went out. Customer reports this is the second time the car has done this. *tr on first inspection unable to verify complaint, all lights functioning as they should. Inspected fuses and wiring and all good. While inspecting lights, lights failed after being on only 10 minutes, and turned off. This was a double light failure with both hi & low beam failure, on both left & right lights! Located a technical service bulletin related to this condition. Performed all tests outlined in technical service bulletin and located both front headlamps defective with swollen center fogged over causing lights to overheat and ECM for headlights going into fail safe mode and shutting headlights off. Replaced both front headlight bulbs and verified repairs. After repairs, ran headlights for 30 minutes with no furhter failure. Returned vehicle to customer.

Filed Dec 4, 2012 · Electrical, Lights · 70,000 miles · WA

Hid headlights on this vehicle and taillights go out on there own sometimes just one or sometimes all lights go out. Problem is fixed when you turn the lights all the way off and all the way back on and they stay on for the duration of my drive or go out a few minutes later. Have been pulled over by police multiple times for having lights out. Have seen many toyota prius complaints about this same exact problem.