Body, generic

B0040 Third Row Left Side Airbag Deployment Control

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0040 is reserved for a side airbag at the left seat of a third row, as found in some seven-seat SUVs and vans; most of them protect that row only with an extended curtain. A Joyson (TK Holdings) patent states its seatback side module may serve any row, third included, and a GM application gives rear-row side bags their own gas generators and allows the rear row to be the third. No maker documents B0040 with this meaning. Earlier GM modules assign it elsewhere: Saab manuals for the 9-5 of 2006 and the 9-3 treat B0040 as low resistance in the driver side airbag loop, under 1.5 ohms with 0.2 tolerance for 2 seconds; bulletin 08-09-41-002H also names it for loose CPA retainers. Airbag lamp on.

Likely causes

Poor contact at the side airbag connector of the third-row seat or rear quarter trim
Lead strained by folding or removing the third-row seat
Internal fault in the third-row side airbag

Symptoms

  • Airbag warning lamp on
  • Left third-row occupant may lack side airbag protection
  • Safety note: do not probe the airbag circuit yourself; unplug airbag connectors only with the battery disconnected and the stated wait time observed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

third row left side airbagsquib circuitsrs wiringsrs control module

Related codes

B0048B0030B0041

References: patents.google.com, patents.google.com, saabwisonline.com, saabwisonline.com.