Body, generic

B0091 Left Side Restraints Sensor 1

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0091 covers the first left-side crash sensor, which Mitsubishi places in the front door and lists as DOOR SATEL SENS LH with the J2012 title in brackets. The airbag unit checks it with the ignition on and stores a subtype after a two-second delay: -11 for a short to ground, -55 when the configuration held in the unit does not fit the vehicle, -81 for a communication fault, plus further bytes. Door satellites of this kind are usually pressure sensors: Bosch explains that the sealed door cavity acts as the sensing volume, so a crush raises pressure and the module can decide within about 5 ms. Continental sells a pressure satellite for the same task. With B0091 set, the airbag lamp lights and left side impact sensing may be weakened.

Likely causes

Short or poor contact in the door harness or connector to the sensor
Internal fault of the front door satellite sensor
Airbag unit configuration not matching the vehicle (Mitsubishi subtype -55)
Internal fault of the airbag diagnosis unit

Symptoms

  • Airbag warning lamp on
  • Side and curtain airbags on the left may deploy late or not in a side impact
  • Safety note: airbag system; disconnect the battery and keep the wait time before door work, then have it checked at a specialist workshop

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–500
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

left side impact sensor 1srs wiringsrs control module

Related codes

B0092B0093B0096B0090

References: mitsubishitechinfo.com, mitsubishitechinfo.com, mitsubishitechinfo.com, bosch-mobility.com.