05 Prius,If airbag stays on,is Airbag still working? Thanks

Maybe, but also (and not unlikely) maybe not. The light is on because the airbag computer has codes for you to read telling what the problem is. You should read those codes, or have them read. That way, you'll know what the problem is.

-Chap

 

Hmm, if the previous owner had the codes read, it would have been thoughtful of him to tell you what they were, and then you'd be able to look them up yourself to see what they tell you about the condition of your airbag system.

If you can't get the codes from him, next best thing might be to read them yourself. In Gen 1 you could get airbag codes using a jumper wire and counting blinks; I do not know if that's still true for Gen 2, so that's something to check in the repair manual. But if it works it's easy to do and you don't need a code reader. Otherwise, you could use information on PriusChat to shop for a code reader, or just have a dealership read them for you.

One thing about diagnostic codes and replacing computers: lighting the warning lights and giving you codes telling you about problems is part of the computer's job. Usually when there are lights and codes, that's the computer doing its job—in fact it's proof the computer is working well enough to do that job—and is not a sign that the computer itself is what needs to be replaced. I'm surprised at how often people rush to that idea, as if they don't think anything else can go wrong in a car, or that a computer would never just do its job and tell them about it. Cases of the ECU itself being at fault can happen, but it makes sense to bet on heads or tails before taking the long shot on the coin landing on edge.

So that means starting by getting what the computer is telling you about whatever problem there is, then looking up what that means, whether it's a problem with a sensor, wiring, bad squib connection, whatever. Maybe the code does indicate the ECU needs to be replaced, and if so, then you do that. But if it doesn't, you would just end up putting a new ECU in that would also do its job and tell you about the problem that wasn't fixed.

-Chap

 

Most of the threads you can search up on this forum will be about something called the Mini VCI, often found in eBay or amazon listings for not much money. They are all clones (the cloners drove the original company, XHorse, right out of the business) and they're not all equal, and there are some issues with knowing what you're getting, but that's all covered in plenty of other threads.

Some people have spent a bit more on a cable called VxDiag and report it being more reliable.

The one Toyota actually tests their software with and officially supports is made by Drew Technologies, but that's got a price in the low hundreds. Technically, any cable that meets J2534 standards "should" work with the software, and for the most part the Mini VCI or VxDiag do.

-Chap

 

The car's got something like a couple dozen ECUs and I have trouble keeping straight where they all are (mostly fit into available space under the dash or behind the glove box). Online at techinfo.toyota.com there is probably an overview illustration in the New Car Features manual (that's the "NCF" tab, and it's the book that tells you what all the stuff in the car is and what it does and how and why, so it's a good starting read), and certainly the location-and-routing view in the wiring diagram viewer will show where it is.

-Chap