B0100: Electronic Frontal Sensor 1 Malfunction
7 vehicles · 5 makes
Most Reported On
B0100 is an OBD-II diagnostic trouble code meaning “Electronic Frontal Sensor 1 Malfunction.” This is a body code in the airbag (SRS) system indicating a malfunction with electronic frontal impact sensor 1, one of the crash sensors that detects a frontal collision and tells the airbag controller when to deploy. The system runs a self-check on these sensors and their wiring, and when sensor 1 fails to communicate properly, reads out of range, or shows a circuit fault, this code sets and usually lights the airbag warning lamp. Because it affects crash protection, the airbags or seatbelt pretensioners may not deploy as designed until it's fixed. It generally points to a faulty sensor, its wiring/connector, or the airbag control module. This code is most commonly reported on 2020-2022 Toyota RAV4 (All, Hybrid), 2010-2016 Toyota 4Runner, and 2007-2013 Hyundai Elantra, plus 4 other vehicles.
Common Causes
Diagnostic Tools
To diagnose B0100, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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Vehicles Affected (7)
FAQ
What does B0100 mean?
B0100 stands for "Electronic Frontal Sensor 1 Malfunction." This is a body code in the airbag (SRS) system indicating a malfunction with electronic frontal impact sensor 1, one of the crash sensors that detects a frontal collision and tells the airbag controller when to deploy. The system runs a self-check on these sensors and their wiring, and when sensor 1 fails to communicate properly, reads out of range, or shows a circuit fault, this code sets and usually lights the airbag warning lamp. Because it affects crash protection, the airbags or seatbelt pretensioners may not deploy as designed until it's fixed. It generally points to a faulty sensor, its wiring/connector, or the airbag control module.
What are the most common causes of B0100?
The most common causes of B0100 are: Faulty frontal impact (crash) sensor, Damaged, open, or shorted sensor wiring, Corroded or unseated sensor connector, Connector damage from a prior collision or repair, Poor ground or power supply to the sensor, Faulty airbag (SRS) control module. The specific cause varies by vehicle.
How much does it cost to fix B0100?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by B0100?
Au7o has documented B0100 across 7 vehicle models from 5 manufacturers: Chevrolet, Hyundai, Jeep, Kia, Toyota.
Sources (12)
- mediaNBC News: Toyota recalling 1.12 million vehicles over potential air bag issue
- mediaWOAY: Toyota recalls nearly 1 million vehicles due to potential defective airbag sensor
- mediaWTVR: Toyota recalls 1 million vehicles over airbag sensor glitch
- mediaRecall Explained: Toyota RAV4 recalls and NHTSA complaint data
- ForumRAV4 World: New RECALL for 2020-2021 RAV4s
- manufacturerToyota Pressroom: Toyota is conducting final phase of Takata airbag safety recall
- manufacturerToyota: Look up Safety Recalls & Service Campaigns by VIN (Takata)
- mediaConsumer Reports: Toyota Recall to Replace Airbags Again | Takata
- ForumToyota 4Runner Forum: Takata Airbag Recall
- manufacturerToyota: DO NOT DRIVE Advisory for Certain 2003-2005 Models with Recalled Takata Airbags
- otherCarProblemZoo: Hyundai Elantra Front Air Bag Sensor Control Problems
- otherJustia: Hyundai Elantra 2007 Air Bags Sensor/Control Module Recall 11V179000
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.