This code indicates that the vehicle's primary communication network has lost its data link with a secondary body control module (BCM B). It means the main computer is no longer receiving the required digital signals from this specific module, which typically controls interior and body electrical systems.
Corroded, loose, or damaged wiring and connectors can interrupt the data bus, power, or ground circuits to the module.
The module itself may have internally failed, preventing it from powering on or transmitting data on the network.
A short or open circuit on the CAN or LIN bus can isolate the module from the rest of the vehicle's network.
A weak battery or failing alternator can cause system voltage to drop below the threshold required for the module to stay online.
The engine computer may have an internal fault preventing it from reading the network, though this is extremely rare.
No, it almost never does. The PCM sets this code because it cannot hear from the Body Control Module B. Replacing the PCM will not fix a broken wire or a failed Body Control Module, which are the actual causes in almost all cases.
Yes. Electronic modules require stable voltage to communicate on the network. If battery voltage drops too low, the Body Control Module may shut down and drop off the network, triggering the code.
Depending on the manufacturer, it is often a secondary controller handling specific body electronics like lighting, locks, or climate, separate from the primary Body Control Module (BCM A).
It depends on which systems are affected. If the module controls safety features like exterior lighting, wipers, or the immobilizer, the vehicle may be unsafe or unable to start.