B1826 is Toyota's code for an open circuit in one of the front side airbag firing loops. The full number is B1826/56. The module powers that loop, watches it, and stores the code when the return signal reads open for two seconds. The squib it is watching lives inside a front seat side airbag, so most of this job happens at the seat rather than at the dash.
Toyota calls the airbag module the center airbag sensor assembly, shortened to airbag sensor assembly on the later charts. It measures every firing loop on the vehicle at key on and keeps measuring while the car runs. The side squib circuit leaves that module, travels through the No. 2 floor wire, passes under the seat, and ends at the front seat side airbag assembly, which holds the inflator and its igniter.
The side naming on this code is worth checking against your own manual before anyone pulls a seat. The Tacoma manual titles B1825 through B1828 as the side squib LH circuit and names the front seat airbag assembly LH as the trouble area. Older Prius and RAV4 manuals title the same block as the side squib on the P seat side, which is the right seat on a left hand drive car and the left seat on a right hand drive one. Same circuit, different label, and the vehicle in front of you decides which seat to open.
The four numbers in the block split by fault type. B1825 is a line short, B1826 is the open, B1827 is a short to ground, and B1828 is a short to battery positive. Toyota lists the same three trouble areas for all of them: the floor wire, the front seat side airbag assembly, and the airbag sensor assembly.
Circuit. The number describes a measurement the module took, and it keeps reporting until the loop reads closed again.
The one place it crosses into crash territory is a vehicle that took a side hit. A deployed seat airbag leaves an open squib, so B1826 sits next to a locked crash record on plenty of collision cars. The airbag has to be replaced either way, and the stored record is a separate line item.
No. Clearing the module's memory does not reconnect a broken wire or refill a spent airbag, and the code returns at the next key on. Repair the circuit first. Once a good seat airbag is installed and the wiring reads correct, the light goes out on its own if the loop was the only fault stored.
If the car was in a side collision, the module is also holding crash data, and our airbag module reset clears that from your original unit. Genuine OEM seat side airbags are searchable by vehicle in the parts store.
B1826/56 belongs to Toyota and Lexus, which share the same chart and the same center airbag sensor assembly naming. Scion models built on the same platforms use the number too. It only appears on vehicles built with front seat side airbags, which is why a base trim from the same year will never store it. Everything above B0999 is manufacturer defined, so a B1826 read from another brand's module means something else entirely.
Disconnect the battery and wait out the discharge time before anyone unplugs a squib connector. Then slide the seat and look underneath. The connector at the seat base and the length of harness that flexes with the seat track are where these open up, and a visual inspection usually finds it. Wiggling the connector with the scan tool watching the code is the fastest confirmation you have the right spot.
If the wiring checks out, the squib inside the seat airbag is next, and the module after that. Related Toyota codes are B1825 for a short in the same circuit, B1821 for the opposite side, and B1801 for an open driver airbag squib. If you need a seat airbag we do not have listed, send us a part request with the year, model, and trim.
Related codes: B1825, B1821, B1801
Keep reading:
Code scope: Toyota, Lexus. The same number can mean something different on another manufacturer, so match the code to your make before you act on it.
A reset clears stored crash data. A replacement part fixes a hardware fault. We have read these codes since the nineties and will tell you which one you are looking at.
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Toyota parts and codes · Do not see it listed? Request a part or call 501-988-0611.