BRAKE FAILURES ON 04+ PRIUS

O.K. after having to CALL the dealer and PICK UP the paperwork myself, here is what I found out...

The RO lists code C1247 (brake pedal strok sensor) as found in memory. It says that they tested the ABS system "thoroughly", and that "all systems check good by Toyota's standards and all components are working properly at this time; malfunction may have been a one-time occurrance; cleared diagnostic code and test-drove vehicle; is working properly at this time". Hopefully, this will mean something to the knowledgable...

Unfortunately, this is the closest dealer to where I live, and where the incident occurred so 24 Roadside Service towed it to these guys. For my planned service work I will try to find another dealer. I am unimpressed with these folks. They can't even answer their phones before the fifth ring! :angry:

 

<div class='quotetop'>QUOTE(efusco @ Nov 10 2005, 09:49 PM) [snapback]153896[/snapback]</div>

Actually, I hate to disagree w/you BUT: I disagree with you. I've had this happen twice. Once, when I started the car, there was a glitch on "startup", the car came on [normally], but the brakes didn't work (there are *some* brakes, but you *do* have to hit them hard to actuate them), and the second, (today), when my whole system failed on me (no brakes, no hybrid system, nothing; look up my other post on this).

I've had mine since 2004 and I've actually been quite happy with it and want another for my wife, but it is quite disappointing to have glitches happen like this (it sort of gives you "shell shock", if you know what I mean). I just want my car to *work* right.

I'll post a followup (to my original post) regarding the system failure to let you know what happened with the brakes and hybrid system...

-= Dave =-

 

<div class='quotetop'>QUOTE(galaxee @ Nov 10 2005, 09:44 PM) [snapback]153856[/snapback]</div>

Sorry . . . probably my fault.

 

I'm resurrecting this thread because my dad owns a 2007 and had brake trouble a couple of days ago. The brakes would not allow a smooth stop. His dealer's tech retrieved DTC C1247 but it does not appear that any parts were replaced. I suppose they are waiting for my dad to see whether the problem comes back, before replacing parts.

I did a PriusChat search and this string is the only one that mentions DTC C1247. If any other members have experienced a similar problem, please comment.

 

I did a Google search on that code. A PDF file comes up, but I can't copy and past from a PDF code. Here is the link DTC C1247

 

without the inf code to go with it, can't really say much. DH has seen a stroke sensor code exactly once. at the shop they probably ran the checks, cleared the code, it didn't come back immediately, they figured it could have been a glitch, send it back out to return if the problem occurs again.

it's been so long that i don't remember how jandmayra's case turned out specifically, but i'm pretty sure it was satisfactory.

 

This problem happened again to my dad's 2007 at the end of July. He says that he was going at ~30 mph when he tried to stop, and the car took an abnormally long amount of time to slow down. So he had his Prius towed to the dealer. He sent me a copy of the repair invoice; here are the details:

9,957 miles. DTC C1247 appeared and would not clear. Could not perform zero point calibration or initialize linear valve. The brake stroke sensor and wiring was found OK. So the tech replaced the skid control ECU, 89540-47100. The car was road tested and found to be OK.

 

This is from priuslovers,
I had a strange experience with my brakes. My wife and I took a short vacation in lake tahoe and the weather was cold and raining (30 to 40 degrees). The car was parked outside for a few days and not driven. When I started the car and depressed the brake pedal it made a high pitched noise. The car seemed to run ok and the brakes functioned properly but the noise continued until we left and drove to warmer weather. I have not heard the noise since - has anybody had a similar experience and know what the noise was?
Thank you - priuslover.

 

Holy anchient thread!
Mine has squeeled a couple times but it was due to rust build up from working on regen to slow down ... not drag racing to the next red light then stomping on the peddal hard. Have you asked the dealer?

 

Hi Priuslover,

Two possibilities come to mind. The coolant pump makes noise when the car is cold. In which case the synchrony with the brake push was just coincidental.

Sitting for a while, the brake hydraulic resoivor could have leaked down, so the brake electric hydraulic pump may have run at high speed to recharge the resoivor quickly. Normally the hydraulic pump sounds like it turns over just a few times, when you get in the car and put your foot on the brake peddle after the car has been sitting overnight.

 

Was the car moving when it was screeching? If so, it may be a rock got caught between the disks and the pads.

 

Regarding my post #48 above, my dad just reported that he has a recurrence of the same braking problem. I suggested that he ask for the brake pedal stroke sensor to be replaced since the skid control ECU was previously replaced in July. He probably won't have time to have the car serviced until mid-December due to travel plans.

 

My dad's 2007 was repaired a few days ago and I just received a copy of the repair invoice.

11,797 miles. Brake, ABS, VSC lights on. DTC C1245 Stroke Sensor (however I don't find this DTC in the repair manual so maybe C1247 was the real code and a typing error was made by the service advisor). Tech found "open" in brake pedal stroke sensor and replaced it, part # 89510-47010.

Since the skid control ECU had been replaced back in July, I hope this latest action permanently solves the problem.

I'm documenting this for the sake of others who in the future may encounter this low-probability failure. Although the chances are not high that it will happen to you, if it does so it is a very serious matter and can be scary if you're not expecting brake failure.

 

Definitely hitting an oldie but goodie here. Not to beat a dead horse, but this thread came up as I was investigating a problem my daughter had recently with her 08 Prius and wanted to jump in with our details:

First off, a few caveats - I'm an Engineer, and have approached this in a typical engineering fashion. I'm not an automotive engineer, but I did do quit a bit of MechE studies and earn my living as a Software Engineer, and I've got a pretty good handle on both the mechanical and electrical diagnostics. In addition to the Prius, which my daughter drives, we've got a VW Bora, an Audi Q7 and a Porsche 996, and I'm constantly tinkering with all of our cars to find out what makes them tick and how to make them tick better.

On Saturday, 24 April 2010, my daughter was driving over Hwy 17 to Santa Cruz, CA when she rounded a corner and executed a panic brake due to completely stopped traffic. She was able to keep the car under control and avoid collision. ABS likely was engaged. It's likely that the Stroke Sensor failed at this point. One or more calipers continued to be engaged after she stopped stepping on the brake pedal. She drove another several miles in this state, and experienced brake fade when she tried to come to a stop at a traffic light. When she finally pressed fully on the brake pedal, secondary braking was engaged and the wheels locked. She fishtailed, but was able to maintain control of the vehicle and avoid collision. She immediately parked and called me. Vehicle was towed to nearest Toyota dealer. Diagnostics indicated a DTC C1247 Stroke Sensor Malfunction, but upon electrical reset all mechanical functions resumed normally.

Brake failures are pretty frightening, especially when it's your inexperienced teenage kid behind the wheel. However, I suspect that failures of this nature are fairly endemic to all regenerative braking systems. No extent of mechanical controls would be capable of balancing the engine and brakes, so you've got to trust these things to a computer. And I can guarantee you that all software has bugs, especially around edge conditions. It's simply impossible to test for everything, all you can do is document and learn from your field data.

That being said, I would certainly hope that these situations have been heeded and improved by Toyota. I'm reading stuff here that's five years old, which what appear to be ample field reports. Toyota needs to step up to the plate and take immediate action on this stuff, and stop dismissing it as Edmunds/GM propaganda.

 

I posted my recent frightening experience elsewhere in this forum, but just found your post and it struck a chord. I am not an engineer, but am analytical by nature. I can assure you that neither "driver error" nor inexperience played a part:
I was a happy 2004 Prius owner until 4 days ago when, while driving at about 60 mph on a foggy/drizzly 60 degree F. day on freeway blacktop, all warning lights on the dashboard suddenly illuminated, after which I took my foot off the accelerator, began merging across lanes to exit and detected significantly reduced braking power. It is a miracle that I live to tell the tale. I kept my cool and was able to exit the interstate (I-80 near Richmond) and slowly stop the car by depressing the brake pedal full force. Only the passenger rear brake was even partly operational. . Towed vehicle to Toyota dealership where, after 3 days of electronic diagnostics and conversations with the regional service advisers, it was determined that the computer governing the ABS needed replacement. This will be a costly repair but more importantly my sense of safety has been eroded. Has anyone else had this frightening experience? (FYI: odometer110K miles, bought new, gently driven, impeccably maintained)

 

Instead of bumping old threads, would you please go back to your first posting so that we can better help you?

http://priuschat.com/forums/gen-ii-prius-main-forum/19415-brake-failure-2005-prius-11.html

 

sorry. unintended breech of etiquette.

 

NP, and I do understand the need to vent over an issue like this. But I think we can shed some light...