This DTC is stored by communication failure between the F-CAN line and the millimeter wave radar. When DTC U0029-00 is indicated, the F-CAN line has already returned to normal. Check for loose terminals and poor connections at the connectors. If the connectors are OK, clear the DTC and following this troubleshooting.
The functions of the integrated driver support system that will be temporarily canceled when this DTC is recorded can be confirmed with the DTC troubleshooting index.