DTC U0402; Error Signal Received From TCM: Notes

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DETECTION CONDITION & POSSIBLE CAUSE

Description	Error signal received from TCM
Detection condition	Communication error between TCM and radar unit
Fail-safe	Inhibits the mazda radar cruise control (MRCC) system control
Possible cause	DTCs are stored in the TCM. TCM malfunction Radar unit malfunction
System wiring diagram	Not applicable