B0090Left Frontal Restraints Sensor
- Generic OBD-II code · Body
- How the car detects it
- B0090 concerns the left frontal crash sensor, a satellite accelerometer in the front crumple zone that tells the airbag module early how hard the front end is being hit. Bosch notes such upfront units sharpen frontal crash detection beside the central sensors. Several makers use the code exactly so. Acura bulletin 18-016 (2017 ILX) describes B0090-87, a missing signal of the left frontal impact sensor, caused by water entering the connector through a wire size variance; sensor and engine bay harness are replaced. For the Ram 1500, FCA reports B0090-49, internal electronic failure of the left frontal acceleration sensor: after sensor replacement the part number must match the restraint controller (STAR S2408000050), and TSB 08-150-26 (2025 Ram 1500) reflashes the controller. The airbag lamp comes on.
- What you may notice
- Airbag warning lamp on, often after front-end repair or water exposure
- Frontal crash detection relies on the module's internal sensor only
- Safety note: airbag system; disconnect the battery and observe the wait time before touching sensors or wiring, work at a specialist workshop
- Likely causes
- LikelyWater in the left front sensor connector damaging the harness (Acura 18-016)
- PossibleReplacement sensor part number not matching the restraint controller (FCA S2408000050)
- PossibleRestraint controller software needing a reflash (FCA TSB 08-150-26)
- RareSensor damaged by a front-end impact or poor refitting after body repair
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €80 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.