Toyota writes its airbag codes two ways at once, as a five-character DTC and an older two-digit number, so a scan tool prints B1801/51. Once you know how Toyota builds those numbers, most of the list decodes itself.
Toyota calls the airbag computer the center airbag sensor assembly on roughly 2000 through 2015 model years, and the airbag ECU assembly on newer ones. Both names mean the same box. It sits on the floor pan under the center console between the front seats, held by three bolts, with a waterproof sheet underneath that has to go back in the right position.
Toyota's manuals are firm on two points. Disconnect the negative battery terminal and wait at least 90 seconds before any SRS work. And if the assembly has been dropped, or its case or connector shows cracks or dents, it gets replaced rather than reused. Location notes by model are on our Toyota airbag service page.
Every firing circuit on a Toyota gets four consecutive codes in one fixed order. Start at the base number and count up: line-to-line short, open circuit, short to ground, short to battery positive. B1800, B1801, B1802, B1803 is the driver airbag squib in that order, B1805 through B1808 is the front passenger, and the same four steps run through every other squib on the car.
Toyota does not publish a code that reads crash recorded the way some manufacturers do. After a deployment the module writes the event into memory and locks itself, while the circuits whose squibs are spent report as opens. A deployed car often scans as a run of B1801, B1806, B1901 and B1906 with nothing naming the collision. That stored event is what a module-level crash data reset addresses. The exceptions are B1785 and B1787, the occupant classification collision detection codes, which Toyota's manual says can be cleared with a zero point calibration when no collision happened.
Codes with a link have their own page. Crash data clears with a module reset; hardware and circuit faults need the part fixed or replaced first.
| Code | Meaning | Type |
|---|---|---|
| B1000 | Center airbag sensor assembly internal malfunction. The module failed its own self-test. | Hardware fault |
| B1100 | Center airbag sensor assembly internal malfunction, same fault on Sienna-generation numbering. | Hardware fault |
| B1610 | Front airbag sensor RH malfunction. | Hardware fault |
| B1612 | Lost communication with the front airbag sensor RH. | Circuit fault |
| B1615 | Front airbag sensor LH malfunction. | Hardware fault |
| B1620 | Side airbag sensor RH circuit malfunction. | Hardware fault |
| B1625 | Side airbag sensor LH circuit malfunction. | Hardware fault |
| B1650 | Occupant classification system malfunction reported up to the airbag module. | Hardware fault |
| B1653 | Seat position airbag sensor circuit malfunction. | Circuit fault |
| B1656 | Seat belt buckle switch LH circuit malfunction. | Circuit fault |
| B1660 | Passenger airbag on and off indicator circuit malfunction. | Circuit fault |
| B1690 | Door side airbag sensor RH malfunction. | Hardware fault |
| B1695 | Door side airbag sensor LH malfunction. | Hardware fault |
| B1785 | Front occupant classification sensor LH collision detection. Clearable by zero point calibration when there was no collision. | Crash data |
| B1787 | Rear occupant classification sensor LH collision detection. | Crash data |
| B1790 | Communication circuit fault between the occupant classification ECU and the center airbag sensor assembly. | Circuit fault |
| B1794 | Open in the occupant classification ECU battery positive line. | Circuit fault |
| B1800 | Short in the driver side squib circuit. | Circuit fault |
| B1801 | Open in the driver side squib circuit, often the spiral cable. | Circuit fault |
| B1802 | Short to ground in the driver side squib circuit. | Circuit fault |
| B1803 | Short to battery positive in the driver side squib circuit. | Circuit fault |
| B1806 | Open in the front passenger side squib circuit. | Circuit fault |
| B1811 | Open in the driver side squib second step circuit on a dual-stage airbag. | Circuit fault |
| B1816 | Open in the front passenger side squib second step circuit. | Circuit fault |
| B1821 | Open in the side squib RH circuit. Side assignment varies by model, so confirm against your manual. | Circuit fault |
| B1826 | Open in the side squib LH circuit. | Circuit fault |
| B1831 | Open in the curtain shield squib RH circuit. | Circuit fault |
| B1861 | Open in the driver side knee airbag squib circuit. | Circuit fault |
| B1901 | Open in the front seat belt pretensioner squib RH circuit. | Circuit fault |
| B1906 | Open in the front seat belt pretensioner squib LH circuit. | Circuit fault |
| B1135 | Driver pretensioner squib. | Circuit fault |
| B1140 | Passenger pretensioner squib. | Circuit fault |
Nothing at the parts store will read these. A basic OBD2 reader talks to the powertrain module on the emissions channel, and the airbag system answers on a Toyota protocol. The factory software is Techstream, also sold as GTS, connected at the DLC3 with the ignition on. Techstream also runs a check mode that raises detection sensitivity for intermittent squib faults that pass a normal scan.
The occupant classification system needs a zero point calibration and sensitivity check after the occupant detection ECU is replaced, after the front passenger seat comes out, after loosening any bolt holding that seat, and after seat covers or seatback trays go on. The check standard is 27 to 33 kilograms using solid weights, seat empty, vehicle level.
Driver squib codes come through constantly and the airbag itself is usually fine. Toyota's trouble-area list for B1800 through B1803 names three things in that circuit: the module, the spiral cable, and the steering pad. The spiral cable is the only one that moves, so it is the one that wears. A frayed conductor sets the line short, a broken one sets the open. B1801 and B1811 together are the first and second stage of one dual-stage driver airbag, both running through the same clock spring.
The other steady one is occupant classification. Toyota recall 23TA15, filed with NHTSA as 23V-865, covers occupant classification sensors on 2020 through 2022 Camry, Corolla, Highlander, RAV4, Avalon and Sienna Hybrid that can short. Toyota released the remedy in phases starting with the most humid states, saying the failure shows up sooner there, which put Arkansas cars early in line.
It is the older two-digit code Toyota used before five-character DTCs, carried forward on the charts. Several modern codes share one legacy number. B1800, B1801, B1802 and B1803 are all 51, because the old system could only report driver squib circuit without saying which failure mode.
No. A standard reader only talks to the engine control module over the emissions channel. You need Techstream or an aftermarket scanner that lists Toyota SRS coverage. A reader saying no codes while the light is on has not reached the module.
Toyota requires a zero point calibration and sensitivity check after the front passenger seat comes out, and even after loosening any bolt that secures it. Skip it and the occupant classification system stays uncalibrated, which lights the SRS warning and the Passenger Airbag OFF indicator.
Both run through the spiral cable, so a genuinely failed clock spring sets both and a good replacement clears both. Codes that survive point at the rest of the circuit: the instrument panel wire, the connector at the steering pad, the steering pad itself, or the module. Aftermarket clock springs are a known repeat-failure item.
Keep reading:
Crash data clears with a reset of your own module. A hardware fault needs the part. Either way, call and we will confirm.
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