OBD-II code B0079 indicates a fault in the deployment circuit for the driver seat belt pretensioner B. The restraint control module (RCM) has detected an electrical issue—such as an open, short, or out-of-range resistance—that may prevent the pretensioner from activating properly in a collision.
The pretensioner itself has an internal open or short circuit, often due to age, manufacturing defect, or previous deployment.
Wiring between the RCM and the pretensioner may be chafed, pinched, broken, or have corroded terminals, causing high resistance or an open circuit.
The connector at the pretensioner may be loose, not fully seated, or have bent pins, leading to intermittent or high-resistance contact.
Damaged insulation can cause the pretensioner wiring to short to the vehicle body or to a power source, triggering the fault code.
An internal failure in the RCM is possible but rare; it should only be considered after all other circuit and component checks are exhausted.
The vehicle may drive normally, but the driver seat belt pretensioner may not deploy in a crash, increasing the risk of injury. It is a safety concern that should be addressed promptly.
Replacing a pretensioner involves handling pyrotechnic devices and the airbag system, which can be dangerous if not done correctly. Professional diagnosis and repair are strongly recommended.
No, the code must be cleared with a scan tool. The light will remain on until the fault is resolved and the code is manually erased from the restraint control module.
It is very unlikely. The most common causes are a faulty pretensioner or wiring issue. The control module should only be suspected after all other possibilities have been thoroughly tested and eliminated.