Check engine light came on a few days ago and parts store told me these codes: Codes P0446, P0441, C1256, C130 Is there a file I can download that has more information on these codes? Is there really a C130 code or did I not write it down correctly? Should I go to another parts store that is willing to give me more details on the codes? Thanks in advance for providing info about what might be going on. I have a 2006 Prius with 217,000+ miles and some rust.
you can go to the service manual to look up the codes at 'techinfo.toyota.com' but the autoparts readers aren't always specific enough.
Here are more details (went to a different parts store): 1. C1256 - accumulator low pressure malfunction 2. C1300 - Malfunction in Engine Control Unit 3. P0446 - Evaporative Emission System Vent Control Circuit 4. P0441 - Evaporative Emission System incorrect purge flow What does all this mean?
Looks like they didn't give you the right fortune cookie for C1300; it isn't an engine control unit malfunction, but a skid control unit malfunction. The troubleshooting bit in the manual for that isn't very involved: clear the codes, and see if a C1300 comes back. If it does, replace the skid control unit. C1256 is a not-uncommon code about the system that pressurizes the brake fluid, not being able to achieve or hold the proper pressure. It can be set for about five different (related) reasons (the "detection conditions" on its page in the manual), and there can be a couple different 3-digit "INF codes" to help narrow down which reasons triggered it. Regardless of the details, in a Gen 2 it's likely to be fixed by replacing the brake actuator assembly, because that one assembly is where nearly all of the parts are that could be the problem. Replacing it is kind of a chore. But, that code is reported to you by the skid control unit, which is also giving you a code questioning its own sanity. So if that C1300 comes back after clearing, you might want to replace the skid ECU first, and then see whether the saner ECU still thinks you have an accumulator pressure problem. The P0441 and P0446 have to do with the evaporative emission control system for the engine: the system that captures fuel vapors from the fuel in the tank so they don't all waft into the air, and then feeds them to the engine at appropriate times so they can be burned. It's an interesting and kind of subtle system. The troubleshooting tips in the Repair Manual (more info), to help you pin down what triggered those codes and how to fix it, run to 24 pages for P0441 and 14 pages for P0446. That doesn't mean the problem has to turn out to be horrible, though; it could even turn out to be a loose hose somewhere, or the fuel filler cap, even. Troubleshooting to pin down an EVAP problem can take some creativity (and care; it's a system full of fuel vapor, after all), and Toyota's Techstream diagnostic software has features that might make it a lot easier. Also, if you sign in at techinfo.toyota.com for access to the Repair Manual, you also have access to their "University of Toyota" technician training course materials. One of those is totally devoted to understanding and diagnosing evaporative emissions systems, and can be a big help as background for the workup steps you find in the Repair Manual.
Eh, the first two are related; the last two are definitely related and could be something really simple (or not). It's not like the car is in operatic throes of death.
Any of these guys can help you. You also might wanna talk to "Patrick Wong" I was able to fine tune my car with his help and my other buddy from Australia. Good luck with her!
UPDATE: I had the codes cleared and have driven about 40 miles and shut the car on and off a few times and none of the codes have reappeared. I did have some silicone spray put on the seal of the gas cap and rubbed in before I went to have my emissions test and it passed, so I was able to get Colorado license plates, but I had to ducktape the rear one on because the bolts have rusted and I can't get them out.
You probably should get a new gas cap (OEM Toyota). They are not that much and there is more to them than just that seal. I had the low EVAP leak on my 2005 Tacoma last month. I replaced the gas cap and code gone.
