What it means
This code identifies a fault associated with the third row center seat belt pretensioner deployment control. The restraint control module sets it when it detects a problem in that deployment control; the exact fault is specified by accompanying subfault information.
How it works
The third-row center seat-belt pretensioner tightens the center belt during a qualifying crash. The restraint control module monitors its deployment-control circuit, and B0077 indicates a fault associated with that circuit; the accompanying subfault information identifies the specific condition.
Common causes
Most likely first.
- Pretensioner wiring or connector fault
- Open or shorted deployment circuit
- Faulty third row center pretensioner
- Restraint control module fault
Symptoms
- Airbag warning light on
- Third row center pretensioner may not activate in a crash
How to diagnose it
- Read the restraint module's subfault details and freeze-frame data to identify the condition recorded for the third-row center pretensioner circuit.
- Check the third-row center belt and retractor for damage, obstruction, or failure to retract smoothly.
- Inspect the center pretensioner wiring and connectors for looseness, corrosion, damaged pins, or chafing, paying attention to harness sections near folding or moving seats.
- Test the deployment circuit for an open or short using the manufacturer's method and specification.
- If the circuit passes, assess the third-row center pretensioner and then the restraint control module following the manufacturer's diagnostic sequence.
Common fixes
- Repair or reconnect damaged third-row center pretensioner wiring or connector using the approved procedure.
- Repair a confirmed open or short in the center deployment circuit.
- Replace the third-row center pretensioner if testing confirms it is faulty.
- Repair or replace the restraint control module only after the circuit and pretensioner are verified.
Can I keep driving?
The vehicle may be driven, but the third-row center pretensioner may not operate in a crash. Avoid using that seat until the restraint fault is diagnosed and repaired.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.