Body, generic

B0046 Left Curtain Deployment Loop Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0046 appears in none of the accessible J2012 code lists, which jump from B0043 to B0048, and no carmaker or bulletin uses it publicly, so the code cannot be traced to a vehicle. Its title describes an open firing loop of the left curtain airbag that drops from the roof rail. J2012 normally encodes that fault as B0021 with failure type 13: Mitsubishi stores B0021-13 when the left curtain circuit has been open for 2 seconds, and Mercedes-Benz reads B002113 as an open left windowbag squib. GM's Global A modules report the same fault as B0016 04 for the left roof rail airbag. If B0046 is read, trust the text the scan tool shows. Airbag lamp on.

Likely causes

Unplugged or loose curtain airbag connector at the pillar or roof rail
Broken lead in the roof rail harness, e.g. after headliner work
Open igniter inside the left curtain airbag

Symptoms

  • Airbag warning lamp on
  • Left curtain airbag may not deploy in a side impact or rollover
  • 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€100–1,000
Time1–4 h

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

Parts involved

left curtain airbagsrs roof wiringsrs control module

Related codes

B0047B0021B0022

References: mitsubishitechinfo.com, static.nhtsa.gov, saabwisonline.com, autoliv.com.