U0464 is a generic OBD-II network communication code indicating that a control module (most often the PCM) received invalid, implausible, or corrupted data from the Navigation Control Module over the vehicle's CAN bus. Because navigation data is not engine-critical, the code is usually informational and does not by itself indicate a drivability or emissions problem. It points to a fault in the nav module, its wiring, or the shared communication network, not in the engine computer.
Internal failure of the navigation module is the most common cause, as it is the source of the data flagged as invalid. The module may have a hardware fault, corrupted memory, or a failed internal processor.
Loose, corroded, bent, or backed-out terminals in the nav module harness connectors are frequent. Intermittent connection can cause the transmitting module to send incomplete or garbled frames that other modules interpret as invalid.
Low supply voltage, a shared ground issue, or a blown feed can cause the nav module to send corrupted or incomplete data while still appearing partially awake on the network.
High resistance on the CAN high/low lines, a short between CAN wires, or excessive electrical noise from another component can corrupt messages in transit so the receiving module reports them as invalid.
A failed or incomplete software update, or known calibration issues, can cause the module to broadcast data that does not conform to the expected format, triggering U0464 in other modules.
Rare. The module that logged U0464 can in theory misinterpret a valid message, but this is the least likely cause and should only be considered after the nav module, its wiring, power, and the network itself have all been verified.
Almost never. U0464 is a network communication code about the navigation module's data, not an internal PCM fault. Replacing or reprogramming the engine computer is one of the most common and expensive misdiagnoses for this code. The nav module, its wiring, power/ground, or the CAN bus should be confirmed before any controller replacement is considered.
Yes, in most cases. Navigation data does not affect engine operation, emissions controls, or basic drivability. The vehicle can typically be driven normally while the cause is investigated, though the underlying issue should still be repaired.
It can if the underlying condition was a one-time event, such as a momentary voltage drop or a brief network disturbance. Persistent faults will return after the code is cleared and the relevant conditions recur.
Because it is a communication code and not an emissions-system fault, it generally does not cause an emissions failure on its own. However, a stored Check Engine lamp may still be flagged by some inspection programs, and the root cause should be addressed.