This code indicates the vehicle’s network controller has lost communication with Seat Control Switch Module B, typically the passenger-side seat control switch assembly. When the module fails to transmit expected data messages on the communication bus due to internal failure or circuit interruption, the supervisory module logs U0261. This prevents electronic adjustment commands from reaching the seat motors but does not affect engine operation.
Internal electronic failure within the switch assembly itself, such as a damaged circuit board or corrupted microprocessor, prevents the module from powering on or transmitting network messages.
Open circuits, high-resistance connections, or intermittent continuity in the power, ground, or data lines running beneath the seat, often caused by repeated seat movement flexing the harness.
Blown fuse, corroded ground terminal, or supply voltage drop that prevents the module from energizing and establishing communication on the bus.
Short-to-power, short-to-ground, or open circuit in the CAN or LIN bus lines specific to the seat control module, disrupting data transmission between nodes.
The seat switch module was replaced or the battery was disconnected without performing required initialization or programming, leaving the module unrecognizable to the network.
A rare internal fault in the body control module or gateway module responsible for seat network supervision; the engine computer (PCM/ECM) is not involved in seat switch communication.
Yes. This code affects only seat convenience functions and does not impact engine operation, braking, steering, or overall vehicle safety.
No. The PCM does not communicate directly with seat switch modules. This code is almost always caused by the seat switch itself, its wiring, or the body control module. Replacing the PCM is unnecessary and will not resolve the issue.
Some seat modules require specific configuration or calibration after total power loss. If the module was not properly reinitialized, it may fail to communicate until reprogrammed or reset with a compatible scan tool.
Yes. If the fuse protecting the seat control module’s power circuit is open, the module cannot energize and will not communicate, which sets U0261.