2006 Prius huge brake issues dealer can't figure out

welcome to priuschat! what are the codes?

 

Sounds like they are using your checkbook as a troubleshooting tool.

Codes would help.

Galaxy Nexus ? 2

 

yes, it will help the experts here assess the situation.

 

Unfortunately most repair shops, including dealers, troubleshoot this way - by process of elimination. Also, once an electronic part is installed in a vehicle it typically will not be removed, as it is no longer new and the condition of the part is not known until the problem is solved. (I personally would not want a part that has been installed in another vehicle installed in mine as a new part.)

The DTC's usually contain a list of possible problem areas, starting with the most probable. The usual troubleshooting procedure is to go down this list one at a time until the problem is resolved.

I agree with you that after all of the parts were replaced and they still have the same error codes that it appears that none of the original parts were probably defective.

This is disappointing that the dealership, along with Toyota technical help, has not been able to identify the problem without such a long list of expensive replacement parts.

Sorry about your situation.

Maybe some of the Prius repair experts on here can chime in and give us some feedback from their perspective.

 

I do not have the GenII Manual, but willing to speculate that the parts replaced thus far were based on a Troubleshooting "tree" or "flow chart" showing "most likely cause" by a Tech who is not good at troubleshooting or using a meter. We call this shot gunning. Eventually you will hit the target. Likely not all these parts were bad or the codes would have changed or reduced during the process. I further speculate that when they do find and fix the problem, were they to reinstall the original parts replaced up to that point, everything would work just fine. An exception is if they find the real cause shorted out the first parts changed, but then it would also short out the new parts. This is why you do not shotgun. I may be wrong...but think you are getting bit by parts changers. Let us know the final results. Wish you luck.

 

This is what I am showing in my records for the codes (I don't have a 2006 book but they should be the same)

This looks like it could be a 12 volt power supply issue. That is the common thread with the above codes.

 

Disclaimer: I am not an expert on the Prius brake system.

The power supply is a capacitor that stores the 12 volt power to provide one last stop in case of total 12 volt power failure.

In my mind there is no way that all those components can be bad and you still have a problem. The dealer should have followed the troubleshooting flow chart in the book before they started changing out parts. It does not take long to check for 12 volts at a few connectors.

The common thread in the codes listed is a 12 volt power problem. I would start with the battery cables including the ground to the body and then follow the 12 volt power through the system. It could be as simple as a corroded ground. As I checked each connector I would spray it with deoxit and plug/unplug it a couple of times and move on to the next. Only then would I start thinking about replacing parts. The power supply is in the back next to the battery and can be subject to getting wet (Changing a flat in the rain, etc.) so I would look at that connector very closely.

Make sure you get your old parts back.

 

How many times have you had to jumpstart the car?

 

The linear solenoid codes are there because they replaced the ecu and didn't perform the linear offset calibration afterwards. C1377 would be the primary DTC for me to troubleshoot. Find out what information code is setting with the C1377. Also, what was the original code before any parts were replaced?

SPH-D710 ? 2

 

What is the Information code with C1377?

SPH-D710 ? 2

 

So car must have been a salvage title car or its mouse damage. Lots of reports here of mouse damage. They find the wiring very tasty. Car is not garaged right?

To confirm mouse check the cabin filter for mouse nesting signs. That's where they are inhibited as they move into the car.
That and in the spare tire well.

Certain area's of the country prone to that but since you didn't fill out your locale not sure where you live.

 

Yes, wire damage from rodents or an accident is a real problem. The dealership won't even consider looking for any damaged area, they just replace the whole set of wires. Sometimes you can look deeply into all the various nooks and crannies and see the frayed bit, and jumper around it. In that case the cost of repair is just time spent looking, as the jumpering is usually much easier than the whole replacement. That kind of looking is something only you or an independent mechanic can do, with one possible result being that you can't find anything in a reasonable amount of time. However, if you have more time than money, it is a viable way to start.

The problem areas are typically in tight places, like under the dash.

I would also say that the dealer has no real idea if the ECUs are good or bad, given the bad wiring. They are just replacing things without knowing for sure what is going on. They make their decisions based on what is most profitable for their business, not what is lowest cost for the customer.