I had exactly this issue: Mazda radar control error below 20mph and auto-hold not engaging after a remote start (after market, I think it's a compustar brand), everything works fine if started manually. As I spotted right after the remote starter was installed I was pestering my installer for a fix, which in turn pestered the manufacturer of the remote installer. The remote start manufacturer just released a new firmware, I got it installed today, and I'm happy to report that everything works perfect now: Remote start, unlock the door, open door, engine still running, take over by pressing brake pedal, and drive out as usual with all systems working as expected. Get in contact with your installers and hey could perhaps get it sorted.
I had exactly this issue: Mazda radar control error below 20mph and auto-hold not engaging after a remote start (after market, I think it's a compustar brand), everything works fine if started manually. As I spotted right after the remote starter was installed I was pestering my installer for a fix, which in turn pestered the manufacturer of the remote installer. The remote start manufacturer just released a new firmware, I got it installed today, and I'm happy to report that everything works perfect now: Remote start, unlock the door, open door, engine still running, take over by pressing brake pedal, and drive out as usual with all systems working as expected. Get in contact with your installers and hey could perhaps get it sorted.
I purchased my 2018 CX-5 just a few weeks ago and the dealer had a 3rd party install a Compustar 2-way remote starter in it. I thought it was just an intermittent issue, but I noticed that sometimes it would display the "Mazda Radar Cruise Control Disabled under 20 MPH" error message. And then the Auto Hold function would also not work (it would just flash when I pressed the button). Weirdly, even with the error message the MRCC works fine. After reading here about the remote starters I have verified that this only happens when I remote start it, every time. I will be bringing it to the dealer and see what they can do. In the mean time, after remote starting it I get in and turn it off and restart the engine and it then works fine.
I had exactly this issue: Mazda radar control error below 20mph and auto-hold not engaging after a remote start (after market, I think it's a compustar brand), everything works fine if started manually. As I spotted right after the remote starter was installed I was pestering my installer for a fix, which in turn pestered the manufacturer of the remote installer. The remote start manufacturer just released a new firmware, I got it installed today, and I'm happy to report that everything works perfect now: Remote start, unlock the door, open door, engine still running, take over by pressing brake pedal, and drive out as usual with all systems working as expected. Get in contact with your installers and hey could perhaps get it sorted.
Do you happen to have a remote start installed? I just had a third lady install one in my 2018 CX-5 and in now getting that same message.
Problems started after Automate remote start installed today 9/14/2019
Problems started after Automate remote start installed today 9/14/2019 on a new CX-5. I get the TPMS light on or flashing while the car is being warmed up. As soon as I drive off it goes off and stays off, the installer said it wasn't a problem and that it's just something with the installation and not to worry about it. Now I was showing wife how to start it and we did and the "Radar Cruise Control is Disabled under 20 MPH" message popped up. The message goes away if you turn off cruise control or it's fine if you start it normally.
There are no problems with the car if started normally
There are technically no problems with the car if started with the remote starter, the TPMS goes off and the cruise control should work once I resume 40+