Nissan's code list does not run in tidy blocks the way GM's or Ford's does. It interleaves, so the same meaning shows up over and over between component groups, and two codes near the end of the list are the only ones that record a collision.
Nissan and Infiniti call the airbag computer the air bag diagnosis sensor unit, abbreviated ACU in the same service manual tables. It watches the airbag and pretensioner circuits, decides when to fire, and logs what happened. Factory removal procedures on Sentra, Rogue and Versa start by removing the center console assembly, which is where the unit sits on those cars.
Around it are parts with their own codes and their own factory names: a crash zone sensor in front of the radiator, front and rear side airbag satellite sensors at the center pillars, front door satellite sensors, seat belt buckle switches, an occupant classification system with its own control unit and seat sensor mat, and the spiral cable, which is Nissan's name for the clock spring. Models we work on are listed on our Nissan airbag service page.
Nissan runs two readouts off the same unit. In user mode the airbag warning lamp blinks a pattern the driver can see, and one of the documented patterns means an airbag or pretensioner has deployed. In diagnosis mode a technician reads either a warning lamp flash code or B-codes on the factory scan tool.
The list repeats on purpose. Between every component group Nissan inserts a band of codes that all resolve to one instruction, replace the diagnosis sensor unit. B1001 to B1015, B1026 to B1031, B1042 to B1047, B1058 to B1063, B1074 to B1079, B1106 to B1111, B1122 to B1127, B1138 to B1143, B1170 to B1175 and B1202 to B1207 are all that same band. Component circuits fill the gaps:
The collision record is B1209 frontal collision detection and B1210 side collision detection. Those are the two the module writes when something actually happened. Everything else is a live circuit reading or the unit reporting on itself.
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 |
|---|---|---|
| B1001 | Control unit. The diagnosis sensor unit is out of order. | Hardware fault |
| B1015 | Control unit, same band as B1001. Replace the sensor unit. | Hardware fault |
| B1017 | Occupant classification control unit failure. | Hardware fault |
| B1018 | Occupant classification sensor failure, the seat mat. | Hardware fault |
| B1022 | Occupant classification control unit communication failure. | Circuit fault |
| B1023 | Passenger airbag off indicator circuit, open or shorted. | Circuit fault |
| B1033 | Crash zone sensor out of order. | Hardware fault |
| B1035 | Crash zone sensor communication failure. | Circuit fault |
| B1036 | Crash zone sensor mismatch. The wrong sensor is installed. | Hardware fault |
| B1038 | Crash zone sensor circuit open or shorted to battery. | Circuit fault |
| B1040 | Crash zone sensor circuit shorted or shorted to ground. | Circuit fault |
| B1049 | Driver airbag module circuit open, including the spiral cable. | Circuit fault |
| B1050 | Driver airbag module circuit shorted to a power supply. | Circuit fault |
| B1051 | Driver airbag module circuit shorted to ground. | Circuit fault |
| B1052 | Driver airbag module circuits shorted to each other or to themselves. | Circuit fault |
| B1054 | Driver airbag module circuit open, second driver circuit. | Circuit fault |
| B1065 | Passenger airbag module circuit open. | Circuit fault |
| B1066 | Passenger airbag module circuit shorted to a power supply. | Circuit fault |
| B1067 | Passenger airbag module circuit shorted to ground. | Circuit fault |
| B1081 | Right front seat belt pretensioner circuit open. | Circuit fault |
| B1086 | Left front seat belt pretensioner circuit open. | Circuit fault |
| B1113 | Right satellite sensor out of order. | Hardware fault |
| B1115 | Right satellite sensor communication failure. | Circuit fault |
| B1129 | Right side airbag module circuit open. | Circuit fault |
| B1134 | Left side airbag module circuit open. | Circuit fault |
| B1145 | Right curtain airbag module circuit open. | Circuit fault |
| B1150 | Left curtain airbag module circuit open. | Circuit fault |
| B1209 | Frontal collision detection. The front airbag or front pretensioner deployed. | Crash data |
| B1210 | Side collision detection. The side or curtain airbag deployed. | Crash data |
| U1000 | CAN communication circuit. The unit lost the bus for two seconds or more. | Communication fault |
| B1019 | Passenger air bag module. | other |
| B1020 | Passenger air bag short. | Circuit fault |
| B1007 | Diagnosis sensor unit fault. | Circuit fault |
Nissan routes every bit of SRS self diagnosis through either the airbag warning lamp or the factory scan tool. There is no generic OBD2 path documented anywhere in the restraint section, so a code reader from the parts store returns nothing while the light is on. The factory tool named in the manuals is CONSULT.
The tool sorts memory into three buckets. Current faults and past faults both live in the self diagnosis screens, and past faults can be erased. The third bucket, the trouble diagnosis record, cannot be erased at all.
The manual never uses the word locked, but the outcome is the same. The B1209 procedure walks through whether the front airbag deployed and whether the pretensioner activated, and if either did, the last step is to replace the diagnosis sensor unit. Worth noting on the occupant side: Nissan sells the classification sensor and its control unit only as an assembly with the passenger seat cushion, and there is no separate zero point routine published for it the way there is on some other makes.
When a Nissan sets a driver airbag circuit code, the spiral cable is the first thing to look at, and Nissan's own manual says so. The definitions for B1049 through B1052 and B1054 through B1057 all read including the spiral cable, and the repair order runs harness, then driver airbag module, then spiral cable, then the sensor unit.
The other steady complaint is a passenger airbag off light with a grown adult in the seat. The occupant classification trouble state does exactly that: the passenger bag is suppressed, the off indicator lights and the airbag warning lamp blinks. NHTSA recall 16V244000 covers a long list for this, including 2013 to 2016 Altima, Sentra and Pathfinder, 2014 to 2017 Rogue, 2015 to 2016 Murano and 2016 to 2017 Maxima. Run the VIN before buying parts.
Nissan repeats the control unit band throughout the list. Both codes resolve to the same instruction, replace the diagnosis sensor unit, and several other bands in the B1026 to B1207 range say it too.
No. Nissan documents SRS diagnosis only through the airbag warning lamp or the factory scan tool. The restraint system is not on the generic OBD2 path.
Driver airbag module circuit open, and the manual explicitly includes the spiral cable in that circuit. The clock spring behind the steering wheel is the more likely culprit than the airbag itself.
That is the documented occupant classification trouble state. Check the VIN against NHTSA recall 16V244000 first, which covers a wide swath of 2013 and newer Nissans for exactly this.
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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Nissan parts and codes · Do not see it listed? Request a part or call 501-988-0611.