U0277 indicates a loss of communication on the CAN (Controller Area Network) bus between the vehicle's main computer (PCM/ECM) and the Seat Control Module K, which manages the driver's seat functions such as adjustment, heating, cooling, and memory positions. This is a network communication fault, not a problem with seat mechanics themselves.
The seat control module itself has internal electrical failure, making it unable to respond to network queries or transmit data.
Physical damage to the seat module wiring harness, broken/corroded pins in the connector, or chafed wires from seat movement.
Blown fuse, failed relay, or poor ground connection to the seat module preventing it from powering up and communicating.
A short or open circuit on the CAN bus affecting multiple modules, though this typically sets additional communication codes.
The seat module may have lost its calibration or require reprogramming, often after battery disconnect or module replacement.
The main vehicle computer's network communication circuitry has failed—this is extremely rare and should be diagnosed only after all other possibilities are ruled out.
No. While some shops may suggest replacing the PCM, this is almost never the correct fix for U0277. The PCM itself is rarely the cause—communication issues are far more commonly traced to the module itself, its wiring, or power/ground supply.
Yes, the vehicle will typically drive normally, but you will lose all powered seat functions including adjustment, heating, cooling, and memory presets. The car is not rendered undriveable by this fault.
No. While clearing codes may temporarily extinguish the check engine light, if the underlying communication loss remains, the code will reset on the next startup cycle. The actual cause must be diagnosed and repaired.
U0277 is less common than many codes, but it occurs more frequently in vehicles with complex power seat systems and multiple seat memory features. The failure rate of seat control modules varies significantly by manufacturer and model year.