This code indicates that the vehicle's high voltage system interlock loop on circuit B is not behaving as expected. The interlock is a continuous safety circuit that confirms high voltage connectors and service disconnects are fully seated before the system allows high voltage contactors to close.
A partially unlatched high voltage connector or service disconnect breaks the interlock loop and is the most common real-world cause.
Corrosion, bent pins, chafed harness, or a broken wire in the interlock circuit interrupts continuity and triggers this performance code.
The interlock input circuitry inside the junction box or contactor housing can fail internally while the rest of the unit appears functional.
A worn or contaminated service disconnect switch can report an intermittent or out-of-range interlock state.
The module that monitors the interlock loop can misinterpret loop state due to internal circuit failure; this is uncommon and should only be considered after the loop itself is verified.
Control-module failure is extremely rare for this code and should only be suspected after the entire interlock loop and all sensors are proven good.
Typically the vehicle will not allow high voltage operation with this code active, so driving is usually not possible. Do not attempt to force the system into operation until the interlock loop is verified.
No. This is almost always a wiring, connector, or interlock-loop integrity issue, not a battery capacity or cell failure.
No. Replacing the control module is a common but usually incorrect recommendation. The interlock loop, connectors, service disconnect, and harness should be proven faulty first; the module is the least likely cause.
Yes. A service disconnect that is not fully seated or has contaminated contacts is one of the most common triggers for an interlock performance code.