B0101: Front Crash Sensor Circuit Malfunction
A fault has been detected in the front crash sensor circuit, used to detect frontal impacts and trigger airbags/pretensioners.
What B0101 means
B0101 is a generic OBD-II body code in the airbags & restraints group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually off
- Emissions-related
- No
- Limp mode possible
- Not typical
- Drive cycle to clear
- Not required
Get it fixed
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Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Common causes
- 01Sensor damaged after minor impactMost likely
- 02Corroded sensor connector behind bumperPossible
Can I drive with B0101?
Generally yes.
This fault is unlikely to affect how the car drives. Fix it when convenient to restore the affected feature.
Why we rate it low
- Does not normally turn on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose B0101
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just B0101. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Test the circuit
Inspect the wiring and connector at the front crash sensor and srs control module for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Sensor damaged after minor impact; corroded sensor connector behind bumper. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
B0101 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Moderate
- Good DIY job?
- Usually a shop job
Needs a scan tool and some experience with testing.
Parts and systems involved
- Front crash sensor
- SRS control module
B0101 FAQ
What does B0101 mean?
B0101 means “Front Crash Sensor Circuit Malfunction”. A fault has been detected in the front crash sensor circuit, used to detect frontal impacts and trigger airbags/pretensioners.
Is B0101 serious? Can I keep driving?
We rate B0101 as low severity. Generally yes. This fault is unlikely to affect how the car drives. Fix it when convenient to restore the affected feature.
What causes B0101?
The most common causes, from most to least likely: Sensor damaged after minor impact; Corroded sensor connector behind bumper. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix B0101?
Typical labor is about $90–$315 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix B0101 myself?
DIY difficulty is moderate. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.
Will B0101 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.