My 2018 Clarity Touring came with a factory-installed Sirius/XM radio. For the past few months, it occasionally loses signal and displays "No Signal" on the screen. Sometimes it comes back in a minute or two, but more often it remains off so long that I wind up switching to FM. I have had two other Hondas and a Suburu with factory-installed radios, plus an older Pilot with one I installed myself, and this has never occurred in any of them until now. I took it to the local Honda Dealer on 2-21-2022. They found some error codes and said that if the problem occurred again they would replace the radio and/or the antenna. The problem has continued off and on, so I made an appointment to begin the process today. The technician said he could not find anything wrong, so he did nothing. I finally spoke with the general manager, and he insisted that they can do nothing unless the radio malfunctions in their presence. I showed him one of several videos I have made while driving down the highway displaying "No Signal" when there were obviously no obstructions. He still insisted that they cannot do anything about it unless they witness the malfunction. As an engineer, I understand how frustrating intermittent problems can be. Sometimes the only solution is to start replacing parts--beginning with the least expensive--and eventually finding the fix. Have others had this sort of experience? And if so, how did you resolve it?
We had the same issue with our 2016 Pilot. Went back and forth a couple of times with the dealer after I told them it was most likely the antenna. They said their tech told them that if it's an antenna problem, none of the radio bands would work (AM, FM or Sirius). Finally, they agreed to hook up a Sirius simulator and discovered that it was in fact the antenna. Fixed under extended HondaCare warranty. Hopefully, their tech actually learned something. It doesn't take a genius to know that each of the radio bands has its own separate antenna inside that bump on the roof.
I agree that the antenna is the most likely culprit. And any automobile tech who doesn't know that AM, FM, and SiriusXM use three totally different antennas really ought to find another line of work.
I'm concerned about your knowledge of radio frequency if you think you need different antennas for AM and FM.
My 81-year-old memory may need a little tuning up itself, but when I was in engineering school I think I was taught that antenna design depended primarily on wave length--not the modulation method. But commercial AM was relatively long wavelength, and FM was shorter wavelength. My best recollection is that most AM antennae were either long wire, loop, or ferrite wound rods. And most FM antennae were either dipole or nondirectional whips. My vintage GE SuperRadio has both a ferrite rod for AM and a whip antenna for FM, and it still works great. And I think my old Studebaker had an antenna that incorporated both a ferrite coil and a whip. And I believe the SiriusXM very high-frequency antenna is its own beast. But the real point is that the technician who told rodeknyt that FM and AM would also quit working if the XM antenna were bad didn't know what he was talking about.
This is probably insignificant to your problem, but I'll just mention that I experienced frequent Sirius/XM outages like that immediately after I installed an HD rear cam at the top of the rear window. I had to relocate it to the window in the trunk to alleviate the problem.
I took my car to another dealer from whom we had bought three other Hondas over the years. They got the same codes. They replaced the antenna. When that didn't work they replaced the whole system. It was all covered under my Honda Care extended warranty. I bought a new Hyundai Ionic 5 and just sold the Clarity. It was a little sad seeing it on the Carvana truck, but somebody will be getting a nice car.
Even though this is fairly old, I ran across it as I was troubleshooting my "Check Antenna" error message. Agree with you...as a long time HAM, EE and radio enthusiast, the AM and FM bands are waaaaay different wavelengths. In fact, that's why you see many "FM only" radios today...especially in cell phones. Not enough room for the AM antenna, while the headphone wires can be used for FM frequencies. You've got me by 20 years.
All my cars, including my Clarity, have had AM radio tuners, so I was bummed when my MINI Cooper SE arrived with no AM radio. I'd heard this day was coming, but wasn't prepared to accept it (happily, Ford recently reversed their decision to drop AM). To my delight, I learned on the InsideEVs MINI Cooper SE forum that there IS an AM radio tuner in my car! I just had to click my heels together three times, buy an app called Bimmercode, and use it to enable the software-disabled AM radio tuner. Now I can listen to the Detroit Tigers' broadcasts in low-fidelity AM, the way radio sports were meant to be heard. Reading this thread, I now realize MINI must also have installed a fully functional AM antenna that was never meant to be used. It's very perplexing because I never hear any RFI from the MINI EV's circuitry. I did hear AM interference in my 2000 and 2006 Honda Insights, but never in the Clarity.
