B0101: Electronic Frontal Sensor 2 Malfunction
5 vehicles · 5 makes
Most Reported On
B0101 is an OBD-II diagnostic trouble code meaning “Electronic Frontal Sensor 2 Malfunction.” This is a safety-system (SRS/airbag) code, so it should be taken seriously. Modern cars use frontal impact sensors that detect a crash and tell the airbag control module when and how to deploy the airbags. B0101 indicates the airbag (SRS) control module detected a malfunction or circuit fault with frontal impact sensor 2 — meaning the sensor or its wiring isn't reporting correctly, so the module may not be able to rely on it in a collision. This typically lights the airbag warning lamp and can disable airbag deployment until repaired, which is a genuine safety risk in a frontal crash. Note this is a manufacturer-specific code, so the exact sensor location and meaning can vary by make. This code is most commonly reported on 2010-2016 Toyota 4Runner, 2007-2013 Hyundai Elantra, and 2017-2021 Chevrolet Camaro, plus 2 other vehicles.
Common Causes
Diagnostic Tools
To diagnose B0101, 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 (5)
FAQ
What does B0101 mean?
B0101 stands for "Electronic Frontal Sensor 2 Malfunction." This is a safety-system (SRS/airbag) code, so it should be taken seriously. Modern cars use frontal impact sensors that detect a crash and tell the airbag control module when and how to deploy the airbags. B0101 indicates the airbag (SRS) control module detected a malfunction or circuit fault with frontal impact sensor 2 — meaning the sensor or its wiring isn't reporting correctly, so the module may not be able to rely on it in a collision. This typically lights the airbag warning lamp and can disable airbag deployment until repaired, which is a genuine safety risk in a frontal crash. Note this is a manufacturer-specific code, so the exact sensor location and meaning can vary by make.
What are the most common causes of B0101?
The most common causes of B0101 are: Failed front impact/frontal crash sensor (sensor 2), Damaged, corroded or unplugged sensor wiring/connector, Connector or wiring damage from a prior collision or repair, Water intrusion or corrosion at the sensor connector, Poor ground or open circuit to the sensor, Faulty airbag (SRS) control module, Sensor not properly seated or improperly mounted after service. The specific cause varies by vehicle.
How much does it cost to fix B0101?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by B0101?
Au7o has documented B0101 across 5 vehicle models from 5 manufacturers: Chevrolet, Hyundai, Jeep, Kia, Toyota.
Sources (12)
- 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
- otherCarComplaints: 2012 Hyundai Elantra Air Bags Problems
- otherCarComplaints: 2005 Hyundai Elantra Air Bags Frontal Sensor/Control Module Problems
- ForumHyundai Forums: Air Bag Control Module internal failure
- mediaKelley Blue Book: Chevy Camaros Recalled Over Flying Emblems
- ForumCamaro6: Chevy Camaro Recalled For Separating Driver Airbag Emblem
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.