Airbags

B0100 — Front Impact Sensor 1 Performance Fault (SRS)

Severity: high Drive with care, to a shop

What B0100 means

The supplemental restraint system (SRS) control module monitors front impact sensors that detect sudden deceleration in a frontal crash. B0100 is set when the signal from sensor 1 is outside the expected range or does not make sense, so the module can't trust its data. The system usually disables some or all airbags and turns on the SRS warning light.

Symptoms

  • Airbag (SRS) warning light is on
  • SRS is disabled or only partly active
  • Fault appeared after a minor collision, parking bump or front-end repair
  • Warning may come and go

Possible causes

  1. Failed front impact sensor
  2. Damaged wiring or connector after a minor collision
  3. Sensor bent or loosely mounted
  4. Corroded connector pins or poor ground
  5. Body repair left the sensor installed incorrectly or not replaced after an impact
  6. Faulty SRS control module (uncommon)

How to diagnose

  1. Scan all SRS codes with a scan tool that supports airbag systems and review freeze-frame data
  2. Inspect the front bumper, reinforcement and sensor locations for impact damage or deformation
  3. Check that the sensor is tight, correctly positioned and not loose on its bracket
  4. Inspect the sensor harness and connector for breaks, chafing and corrosion
  5. With the battery disconnected and the wait time observed, test circuit resistance and wiring continuity
  6. Check power and ground at the sensor circuit
  7. Clear the code and see if it returns
  8. If it returns, swap in a known-good sensor and retest

Common fixes

  • Replace the front impact sensor
  • Repair the wiring harness or replace the connector
  • Straighten or replace the bracket and mount the sensor properly
  • Clean the terminals and restore the ground connection
  • Replace or reprogram the SRS module if it is the cause

Questions and answers

Can I drive with a B0100 code?

You can drive, but the airbags may not work in a crash. Don't put off the diagnosis for long.

Why did this appear after a minor bump?

Even a light impact can shift the sensor, bend its bracket or damage the wiring. Inspect the front end and the sensor connector.

Can I just clear the B0100 code?

You can, but if the fault remains the code will return and the SRS still won't fully protect you. Find the cause first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.