Check engine light on Valve to the coolant pump failed. Is it right?

[pangzi]

I had my 04 Prius with 71900 mile for one day and the check engine light was on, and the MFD was not workign right (had the well known communication problem with Air conditioning and radio and slow response). I took back to the dealer (unfortunately a Honda dealer but new car dealer nonetheless). They agreed to fix the problems and it has been their for 5 days.

Yesterday they told me the chek-engine-light problem was due to the failure of the valve to the the coollant pump. I don't know what the valve means. They also told me the pump was working fine. Is there a potential problem with the statement? They told me that they replace the valve with a part ordered from Toyota and that was why it took so long, and the check engine light is off now.

They did everything with their own computer with using the MFD and I think they kind of forgot the MFD failed as well. They are working on the MFD now.

[2009Prius]

Sounds similar to this:

Engine light = bad hybrid system coolant valve: Warranty? Help!

You can ask the dealer for the DTC codes and do some research.

[jdenenberg]

Originally Posted by pangzi

I had my 04 Prius with 71900 mile for one day and the check engine light was on, and the MFD was not workign right (had the well known communication problem with Air conditioning and radio and slow response). I took back to the dealer (unfortunately a Honda dealer but new car dealer nonetheless). They agreed to fix the problems and it has been their for 5 days.

Yesterday they told me the chek-engine-light problem was due to the failure of the valve to the the coollant pump. I don't know what the valve means. They also told me the pump was working fine. Is there a potential problem with the statement? They told me that they replace the valve with a part ordered from Toyota and that was why it took so long, and the check engine light is off now.

There is TSB (EG001-08) describing this known periodic problem in 2004 Prii. The new valve is an improved model and the code registered is P1121. It is covered under the 36/36,000 drive train warranty and my dealer (CT) quoted $300 for the repair.

They did everything with their own computer with using the MFD and I think they kind of forgot the MFD failed as well. They are working on the MFD now.

The MFD can be repaired inexpensively, but NOT by a dealer. There is a TSB on this problem as well as it is due to a manufacturing defect in early 2004/2005 MFDs. Do a search for Prius MFD Failure and you will find a full description of the necessary repair procedure that can be done by any experienced electronics technician.

JeffD

[sclieu]

Crap. Now I just got the p1121 error code. I was able to find the technical service bulletin but can't seem to post an external link because I'm newbie here. I found it pretty fast, so you should be able to do so as well by searching terms 'prius p1121'.


The steps to install sound fairly easy to do, but was wondering if anyone has done this. I found the below thread which mentions the part costing around $70, but the link to that web site is bad.
..forums/gen-ii-prius-technical-discussion/39624-coolant-flow-control-valve-air-heating-issue.html

In any case, if anyone has installed this themselves, please give me a holler. If I can figure it out and do it myself, I will definitely post pictures of each step for everyone else.

Thanks.

[sclieu]

Odd... on obd-codes.com, it lists this for toyota code:

P1121

Accelerator Pedal Position Sensor Range/Performance Problem.

[Patrick Wong]

Generic interpretations of Prius DTC often are incorrect. DTC P1121 is "Coolant Flow Control Valve Position Sensor Circuit Stuck".

There are three possible reasons for this DTC. Either the valve is bad, or the cooling system is clogged, or the engine ECU has failed.