Ive have my 2015 is350 for about 4 months and recently I had a airbag light come on. It stayed on for a few days and went away but came right back. Now its stuck. After reading around, I bought a INNOVA 6100P to try to reset the code hoping it will go away, but as soon as I turn off the car and turn it back on, it comes back. The code that comes up is B1851: Open in Rear Side Squib RH circuit. I searched all over and cant really seem to find much info on how to fix this problem. Anyone else had this problem before?

 

Airbag codes aren't super common on a lot of vehicles, let alone Lexus vehicles. For some reason these items don't fail that often, which is why you're running into the roadblock you are. Given it's safety and airbag related, the code will never clear until the problem is repaired, and when it is repaired, it will clear itself immediately.

You already have the code obviously, this pertains to the right rear airbag circuit. According to the information I have access to, it's one of three things: Floor wiring, Right side squib (which is fancy word for the airbag itself), or the airbag sensor assembly.

Ultimately, it's hard even for me as a technician to diagnose airbag items because you can't resistance test the components, they'll blow up, so don't try it. There's special service tools that are essentially connectors with a specific resistor in line to mimic the component you're trying to test that are only available to dealer technicians for the most part.

Has the vehicle ever been in an accident before your ownership in that right rear corner or side area? That would lead me to believe there may be an intermittent open in the wiring. Otherwise, what you can try to do is gain access to the airbag unit itself, and AFTER REMOVING THE NEGATIVE BATTERY CABLE, unplug the airbag (a yellow 2-pin connector), ensure the terminals are looking proper (not pushed out of the connector, no corrosion of any sorts), plug it back in, and hook the battery back up. As stupid as this sounds, I have "repaired" airbag codes exactly like this, only on the underseat connectors of various vehicles. Literally just unplug, check the pins and terminals, and plug back in. If this doesn't resolve the issue, it's more than likely an issue with the airbag itself and would need replaced, but don't quote me on that. When it comes to these repairs it's easier to start with the least expensive and move to the most: Pin/connector fit is free.99 just a little labor on your end, an airbag is likely going to jump into the high hundreds, with the sensor assembly being a couple grand and would possibly need a programming of some sorts at the dealer.

Really what it all comes down to is do the pin fit on your own and after that, you're kind of stuck going to the dealer for a diagnosis just due to the factory tools they have to accurately tell you exactly what's going on.

-Shane

 

Thanks for the info, I guess I really have no choice but to bring it in to have them check it out. I am definitely not comfortable enough with myself to go messing around with an airbag or electrical wiring. I’ve hand wash and detailed the car myself and pretty much spent almost 6 hours just “feeling” the car and I haven’t noticed anything that would make me think it’s been in a accident. I hope it’s just a loose wire.

 

All good, no judgement, good job on knowing your limitations and not diving in and creating a worse issue. I would like to think it'll be something relatively simple given the light went off for a little bit and then came back on. Once you receive a resolution give us an update!

- Shane