B0077 code meaning
Third Row Center Seat Belt Pretensioner Deployment Control
What B0077 means
B0077 stands for the pretensioner at the middle seat of the third row. Hardly any vehicle fits one, and no manufacturer documents B0077 with this J2012 meaning; Mercedes, which equips some models with third-row tensioning retractors, lists only a left and a right unit (B00E7/B00E6). The number is met more often in older GM-built Saabs. The 2006 Saab 9-5 stores B0077 when the airbag module cannot communicate with the driver-side side-impact sensor because of an open or a short, and Saab 9-3 modules of 2003 and 2007 use it for the driver-side B-pillar sensor. On such cars the fault lies in the door or pillar sensor, not in a rear belt. For a genuine third-row centre pretensioner, a stored code means a lit airbag lamp and a disabled unit.
B0077 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0077
- Airbag warning lamp on
- On Saab, side airbag deployment on the driver side may be impaired
- Safety note: airbag sensors and pretensioners belong to the pyrotechnic restraint system; work only de-energised and at a specialist workshop
Common causes of B0077
- Most likelyOn older Saab 9-3/9-5, fault at the driver-side side-impact or B-pillar sensor (older GM meaning)
- PossiblePlug of the third-row centre pretensioner disturbed during seat folding or removal
- Less likelyAirbag module coded for a centre pretensioner that is not installed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Third row center pretensionerSquib circuitSRS control module
What each part of B0077 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). |
| 77 | The exact fault in that area. |
What to do next
- Note B0077 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 B0077
What does B0077 mean?
B0077 means "Third Row Center Seat Belt Pretensioner Deployment Control". B0077 stands for the pretensioner at the middle seat of the third row. It is a generic code, so it means the same on every make.
Is it safe to drive with B0077?
B0077 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0077 fail an emissions test?
B0077 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 B0077 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will B0077 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.