2005 Prius Woes

Most likely you were taken by the repair dealer. The HV coolant pump in the Gen II Prius can form a bubble that interferes with coolant flow and leads to eventual failure of the pump. Lack of cooling causes the HV inverter to shut down when it overheats. Presumably that was the "computer system" part that they replaced.

The replacement was probably not necessary, but it's impossible to say without more data. It is possible that overheating killed the inverter, requiring replacement. The replacement, however, didn't address the underlying problem, which was the bad pump.

Tom

 

Wow, I'm really sorry to hear about what you've had to go through.
I'm just so surprised that this happened to you, I've had all three generations of the Prius and the oldest one (2001 with 150,000) was running like new. I wish i could help. Sorry.

 

Yep, that's sure what it sounds like Randy. Do you have an invoice showing exactly what their "problem with part of the computer system" repair involved? I think it's a pretty safe bet that it never needed to be done.

 

Please refer to your repair invoice and tell us:

1. Part number and description of replaced parts
2. The DTC logged by your vehicle

Then we can tell you if the original problem was related to the inverter coolant pump or not.

 

Diagnostic Trouble Code. For example, P0a93 is the DTC for inverter cooling pump failure.

Vehicle computers almost never fail in the course of normal operation. The Melbourne service department completely misdiagnosed your problem. Please do press your case with the Melbourne dealer and Toyota corporate. File complaints with the city, state, BBB, etc. Don't take no for an answer, as you are 100% in the right.

 

Not a problem with me. It might mean higher labor costs in the long run for consumers, but dealers need to start paying better to attract more qualified diagnostic technicians and get rid of the parts changers. What computer was it that they replaced?

 

Your link noted above is this same thread.

How far did you drive from the time you saw the triangle till you reached the dealer?

 

The ABS ECU? Look like you were had, if that's the case...unless of course it really was failing.


http://priuschat.com/forums/gen-ii-prius-technical-discussion/88228-abs-control-module.html

 

That is the skid control ECU. MSRP is $1,508. Does your repair invoice show any DTC listed?

1. The triangle-shaped warning icon is the master warning light. Its purpose is to alert you that there is a problem. You need to look around at the other warning lights and any icons or messages on the MFD to determine what the problem is.

2. I am wondering what evidence you received to decide that coolant was overheated? Failure of the skid control ECU would not cause any system to overheat. It would cause your braking system to be impaired.

3. Since the skid control ECU was replaced, I assume that one or more of the following warning lights were on: ABS, VSC, BRAKE, or the ((!)) light. Do you recall seeing any of those lights on?

 

With the IC pump DTC, the DC-DC converter shuts down and a weak 12V goes by the wayside in short order. With the 12V failing while the car is still moving under power, many of the computer systems will set DTCs for low voltage. OP made it from Melbourne to home on a failed IC pump without codes due to code reset and cold weather.