Anyone familiar with the operation of the tcu and CAN bus? I am having issues with my 2018 touring with no communcations with the tcu using honda link. I have checked all 3 fuses and they are good. Also, I do get 4 or 5 bars for the tcu connection when the car is turned off. I suspect a bad tcu or a problem with the CAN bus. Is there a vlotage to look for on the CAN bus wiring to show that bus communication is there? I have tried unplugging the tcu connectors and the tcu antenna connectors to see if there is a diagnostic fault logged for the tcu or bus but no fault gets logged and there are no faults for the CAN bus. I had suspected a faulty hood switch but that checked good. I have access to the repair manuals and wiring diagrams but am at a loss as what to check other than replacing the tcu.
If you get the 4/5 bars, the TCU is on the CAN bus, booting, and getting a connection. Your problem is likely on the HondaLink side. (Personally, I hate all this "cloud" nonsense, and removed my TCU years ago.)
It took almost a year back and forth with Honda but it was indeed on their end. I like using it to pre-warm my car during the Chicago winters.
