both codes have to do with communication errors between the ETAC...this is the tiller arm card in the control handle,its not communicating with the power amplifier.
Most probably cause is a broken wire in the harness in the control handle...where it exits at the bottom of the handle and bends....another one that is a possibility is the battery is bad....what is the state of charge of the battery? Low battery voltage,especially while driving will cause this issue.
Check your wiring harness in the control handle to the power amplifier,anywhere it bends and flexs is a good place to start.
Lastly if the battery is good and charged and no broken wires are found then replace the control card in the handle(ETAC Card)