Modern vehicles utilize Positive Crankcase Ventilation (PCV) systems. The rocker cover is often an integral part of this system, housing the PCV valve. A failing gasket can introduce vacuum leaks, disrupting the air-fuel mixture and causing the engine to run rough or trigger a Check Engine Light (CEL).
A: The Leaf has the same steering lock logic, despite being electric. However, the Leaf uses the 12V accessory battery (not the high-voltage traction battery). Leafs are notorious for killing 12V batteries, which triggers B2729-14 constantly. nissan b2729-14
This is the #1 cause. If your Nissan’s main battery drops below 9.6V during cranking or even while idle, the BCM logs this code. Modern Nissans are extremely sensitive to voltage. A battery that is 3 years old or has a dead cell will trigger B2729-14 before it triggers engine codes. A: The Leaf has the same steering lock