U0593 means the primary control module has detected invalid or out‑of‑range data coming from Drive Motor Control Module B. This typically points to a communication error, corrupted data, or an internal fault in Module B rather than a problem with the engine controller itself.
Internal hardware failure or corrupted firmware in Module B can cause it to transmit malformed data.
Open circuits, shorted lines, or high resistance at connectors disrupt data integrity.
Incorrect termination resistance or poor ground reference leads to signal distortion.
Incompatible calibration or outdated firmware on either the primary controller or Module B.
Rare; a defective transceiver in the main controller can misinterpret valid data.
No. The code almost always originates from a fault in Module B, its wiring, or the CAN bus. Replacing the primary controller is rarely necessary and should only be considered after all other causes are ruled out.
A battery disconnect may clear the code temporarily, but if the underlying communication fault remains, the code will return once the vehicle is driven.
A capable OBD‑II scan tool with module‑level data access, a digital multimeter for bus voltage checks, and a CAN bus diagnostic adapter for termination testing.