Code B0073 indicates a malfunction in the deployment control circuit for the second-row left seat belt pretensioner. This means the restraint control module has detected an abnormal resistance or voltage in the circuit that is responsible for firing the pretensioner to tighten the belt during a collision.
The wiring harness routed beneath the second-row seat is highly susceptible to chafing, pinching, or breaking due to seat movement.
The electrical connector attached to the seat belt pretensioner can become loose, corroded, or dislodged, interrupting the deployment circuit.
The internal squib or resistive element within the pretensioner assembly itself can fail, resulting in out-of-spec resistance.
The SRS computer may internally fail, though this is extremely rare and should only be considered after all wiring and components are verified.
It is not recommended. The SRS system will likely disable the second-row left seat belt pretensioner, meaning it will not tighten properly during a crash.
Almost never. Drivers are frequently told to replace the restraint module for this code, but the root cause is almost always damaged wiring under the seat or a failed pretensioner component.
Yes. The constant movement of sliding or folding the second-row seat is the most common cause of stretched, pinched, or broken wires in the pretensioner circuit.
A digital multimeter is required to measure circuit resistance accurately. You should never use a standard test light on an SRS circuit, as it can accidentally deploy the airbag or pretensioner.