U0335 means the hybrid control module has detected a software or calibration mismatch with the Hybrid Battery Pack Sensor Module. The module may be the wrong part, not yet programmed, or sending an identification message the controller does not recognize. This is a communication/configuration fault, not necessarily a failure of the high-voltage battery cells themselves.
A replacement module with the wrong part number, wrong software level, or from a different vehicle/model can send an ID the controller rejects.
Even the correct hardware often must be reflashed or initialized to match the vehicle; if this step is skipped, U0335 sets.
Weak 12 V battery, corroded ground, or poor ignition/power feed can prevent the module from booting fully and reporting its correct software ID.
Open, shorted, or high-resistance communication circuits can corrupt the module's identification message and trigger a software-incompatibility code.
Internal faults in the module can cause it to report garbled or mismatched calibration data despite correct hardware and programming.
Rarely, the controller itself has corrupted or outdated software; this should be verified only after the module, wiring, and programming have been ruled out.
Usually not. This code points to a software or communication mismatch with the battery sensor module, not a failed high-voltage battery pack.
The vehicle may run, but hybrid operation can be reduced or disabled. It is best to diagnose it promptly to avoid being stranded or causing further drivability issues.
Often yes, if the correct module is installed but was not properly initialized or calibrated. Programming with the right software level is a common repair for this code.
No, that is usually the wrong repair. The root cause is most often the sensor module, its programming, wiring, or power supply. Replacing the control module is rarely needed and should only be considered after everything else is ruled out.