B0046 code meaning
Left Curtain Deployment Loop Open
What B0046 means
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.
B0046 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0046
- 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
Common causes of B0046
- Most likelyUnplugged or loose curtain airbag connector at the pillar or roof rail
- PossibleBroken lead in the roof rail harness, e.g. after headliner work
- Less likelyOpen igniter inside the left curtain airbag
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Left curtain airbagSRS roof wiringSRS control module
What each part of B0046 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 46 | The exact fault in that area. |
What to do next
- Note B0046 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0046
What does B0046 mean?
B0046 means "Left Curtain Deployment Loop Open". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with B0046?
B0046 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0046 fail an emissions test?
B0046 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0046 to fix?
Difficulty: workshop only. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will B0046 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.