DTC U0420-00: Error Signal Received From EPS Control Module: Notes

WARNING: This page is about a different car, the 2018 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC U0420:00 RADAR UNIT DETECTION CONDITION AND POSSIBLE CAUSE

Description	Error signal received from EPS control module
Detection condition	Communication error between EPS control module and radar unit
Fail-safe	Inhibits the Mazda radar cruise control (MRCC) system control Inhibits the smart brake support (SBS) system control Inhibits the distance recognition support system (DRSS) control
Possible cause	DTCs are stored in the electric power steering (EPS) control module. Electric power steering (EPS) control module malfunction Radar unit malfunction
System wiring diagram	Not applicable