How read B1801

Once you have read the code, the main thing is just determining why you have it. There are five pages in the Repair Manual (more info) of troubleshooting steps for that code. At the end of those steps you will know whether the issue is in the airbag, the spiral cable, the instrument panel wire harness, or the center airbag sensor assembly.

But you should have the airbag light on if you have that code. Did someone clear the code? If so, the troubleshooting might be harder until it comes back. If an intermittent problem was detected, the code might not come back right away.

If you don't have a scan tool that can read the airbag codes, it can blink them out on the airbag light (various threads on here cover how to retrieve codes by light blinks). B1801 corresponds to blink code 51 on the airbag light. But here's a catch: B1800, B1802, and B1803 also correspond to blink code 51. So you get more information if you have a proper scan tool. But the blink codes are better than nothing if you don't.

I watched that video with no sound, so I'm not sure if that guy mentioned the safety requirements for working in the airbag system. I hope he definitely mentioned disconnecting the vehicle battery and the 90 second wait for the airbag system to be disarmed, and the proper way to handle and set down an airbag if you remove it.

 

Do all of the steering wheel features currently work? (cruise, horn, etc)

Here is the workup for DTC B1801 : https://priuschat.com/attachments/b1801_51-pdf.53001/

Was it replaced with a new OEM, or something else?

Did you (or the Tech) clean the HV battery fan as well?

Most DIYers will use a 'mini-vci' cable (20 usd) and techstream (dealer technician software) installed on a windows device.

 

Most will buy a new OEM cable, or a low mile used OEM cable, and not purchase an aftermarket part for this application.

@3prongpaul finally had some success using a cheaper aftermarket part from ebay, wonder if there is a longevity update coming.

Try the first thread in this search result : https://priuschat.com/search/228929272/?q=84306-0E010&t=post&o=relevance&g=1

Toyota part # 84306-0E010

 

At $25, the seller who is calling that part "OEM" probably also has a bridge you can buy.

 

Ever solved this b1801 airbag light on issue? I replaced the clockspring with genuine Toyota part from dealer. Still have the issue

 

See post #3. The B1801 code gives you a start on identifying the problem, among a small number of possibilities with tests you can do. Once you find out what's causing your B1801, you can fix it.

Replacing the spiral cable will solve the issue if the spiral cable is the issue, as it was for an earlier poster in this thread. On the other hand, if the problem in your case is something else, it won't. That's why following the troubleshooting steps to pinpoint the issue can save you money, compared to just changing one of the possible suspect parts because that happened to work for someone else.

 

Agreed. Don't have techstream obd scanner and labor needed for troubleshooting.

So checking here to see if I can get what is usually the issue for gen 2 Prius with this code.
So with clock spring out of the way, what is the next common failure part I should try replacing ?

 

Sometimes there is one common cause and with that one ruled out, there's nothing very common about any of the rare ones remaining. In those cases, the idea you can come out ahead by doing some speculative parts swaps, compared to a scan tool and the labor for troubleshooting, starts to unravel pretty quickly.

You could next, I guess, try replacing the airbag because it might be the problem, or replacing the wire harness because it might be the problem, but those are both expensive choices and if I were in that position I would rather troubleshoot.