Body, generic

B00B2 Driver Seat Occupant Classification Sensor C

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B00B2 is the third driver seat classification sensor in the J2012 list. No carmaker documents the code publicly. A widely used sensor type is Bosch's iBolt: the four bolts that anchor the seat frame are swapped for sensor bolts, a magnet and Hall element register how far a bending beam deflects, and the unit derives weight and how it is spread, separating an empty seat, a one-year-old, children of three and six, a 5th percentile woman and a 50th percentile man. A Bosch patent adds an accelerometer in the seat back that freezes the classification while jolts would distort the bolts' readings. Which bolt the letter C would denote is not published. With B00B2 stored, the airbag lamp is on and adaptive deployment cannot rely on that input.

Likely causes

Internal fault of the Hall-type sensor bolt at seat anchor C
Sensor bolt overloaded or seat frame bent, e.g. after a crash or wrong torque
Open or poor contact in the lead to input C

Symptoms

  • Airbag warning lamp on
  • Driver airbag cannot be matched to occupant size
  • Safety note: airbag system; disconnect seat and sensor plugs only de-energised (ignition off, battery off, wait time); calibrate weight sensors after replacement, specialist workshop only

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–900
Time0.5–3 h

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

Parts involved

driver classification sensor csrs seat wiringsrs control module

Related codes

B00B1B00B3B00B0B00B4B00A0

References: bosch-presse.de, theautochannel.com, patents.google.com.