Hello all! It has been awhile since I've posted. My 2007 Prius now has 98,000 miles on it, still runs great and up to today, I've had no problems. It may be nothing, but this morning when I drove the car, the engine light came on. The car seemed to run fine, but after returning from my dentist appt I stopped at an Advanced Auto to have them read the code for me. They said I only had one code show up, a PO606- Engine Control Module/Powertrain Control Module Processor. They did NOT clear the code. Anyway, when I powered the car back up and drove away, the engine light went off and has stayed off. I live 3 miles away and it did not come back on. The car seems to drive fine. So....my questions are; 1) Should I be worried? Do you think it will come back on? 2) If it does come back on, is this a costly fix? A dealer only type of fix? 3) Do I trade in this car quickly and scrap my plans on keeping it forever? I called the guy back who tested it to make sure he did not clear the code, and he said he did not, that the light went off by itself. He said I should still go to the dealer and get things checked out because "they'll do that sometimes"...... I doubt it is related, but I did get gas yesterday and MIGHT not have put the cap on perfectly, but then the code did not say "gas cap not tight". I trust the collective wisdom here more then anyplace else......should I be worried? Can I safely drive it? Thank you in advance for any help or advice. Respectfully, Frank D.
How old is your 12 volt battery? If it is original, it may be failing. There is a onboard diagnostic to help you check. Weird stuff happening? MPGs dropping? Test The Battery | PriusChat 1. If it is the battery, the code might be totally different next time. 2. If it is the 12 battery, $175 to $300 depending if you install the new one or have the dealer do it. 3. I wouldn't. Even if it really is the computer failing, should be about $700. There is not better car you could buy for $700
Thank you Jim! I doubt it is the 12 volt battery......I replaced that a couple of years ago with one of those gel type batteries that looks like a six-pack folks recommended here with the Prius adapter kit for it. Offhand I forgot what it was called, but it was a real good one perfect for the Prius. I guess we just wait to see if the light comes back on.... If it does, is it safe to drive much? The car seems fine, runs great, and I'm getting over 50mph consistently. I usually avoid dealerships if I can, but should I go there to get it checked? I'm leery of doing this unless it is wise to do so. If I do need to go to the dealership, at 98k miles what other things should I consider having done. I do my own oil changes, etc, faithfully.....but the car has been so good I have not done anything else. I did just notice the other day that when I filled up the windshield washer fluid, it became empty a few weeks later without using it, so I must have a leak in a hose or the tank. Now I wonder if that might have leaked on the module if it is near it. I'll check that today.
Sounds like an Optima Yellowtop D51R battery. If the module is really bad, it will need replaced, so there is no additional damage if you wait. If you go to the dealer, as about recalls and TSBs that apply to your car. Your maintenance guide http://www.toyota.com/t3Portal/document/omms/07ToyMS_MS0003/pdf/07omsour/2007/07toysmt/71w1smt.pdf suggests replacing the coolant, (both engine and inverter loops) that would be a dealer repair due to the difficulty purging air out. (The inverter loop may be a free recall item) I would drain and fill the ATF WS in the transmission, it is no harder than doing your engine oil. Reconditioning a Toyota Prius - Changing the CVT Transmission Fluid | NotPetroleum Blog
Thanks Jim. So I'll see if the light comes back on. I do remember now I did have my mechanic change the tranny fluid about 2 years ago with genuine Toyota ATF WS. I forgot about that before......sorry. And you are correct, that was the new battery I put in. Sorry, I get a bit forgetful. The Prius has been the best car we've ever owned. I've replaced cabin and air filters, but I will have the radiator fluid done, very good advice. I'll keep watching for the light to see if it comes on.......thank you very much! Frank
You could look around for a used Engine Control Module. It is a plug in unit, so not really that hard to replace once the passenger side dash is removed.
From the manual for P0606: MONITOR DESCRIPTION The ECM continuously monitors its internal memory status, internal circuits, and output signals to the throttle actuator. This self-check ensures that the ECM is functioning properly. If any malfunction is detected, the ECM will set the appropriate DTC and illuminate the MIL. The ECM memory status is diagnosed by internal "mirroring" of the main CPU and the sub CPU to detect random access memory (RAM) errors. The two CPUs also perform continuous mutual monitoring. The ECM sets a DTC if: 1) output from the 2 CPUs are different and deviate from the standards, 2) the signals to the throttle actuator deviate from the standards, 3) malfunction is found in the throttle actuator supply voltage, and 4) any other ECM malfunction is found. This is a self check for "bit rot". As an EE, I tend not to be optimistic about these sorts of things. Having a spare on hand would be good.
Well, it is at the dealership now. They say it is the O2 sensor that triggered the P0606 code, which is the ECM. They said replacing the O2 sensor "should" solve the problem. They also said my water pump was starting to leak. I replied that I have found no coolant drop, and nothing in the driveway. They said it was starting to leak under pressure, and that it will first form a pink crystalline deposit, much like a car battery. They are installing a new water pump. According to the Toyota website, the water pump should be covered under the Certified 100k powertrain warranty. They have to order the O2 sensor, so I have to return for that fix. Since it will take a bit, they gave me a 2013 model 4 Prius to drive home....it is nice! They also have a Prius plug in there for sale, probably one of the only ones in Florida.....they got it from a dealer in Baltimore. It was cool to at least see one.
Which 02 sensor was it, do you happen to have a part number? I'm getting the same code at random. Thanks
