...have found a couple of things that would cause this on my cb. one is the squelch set to low. i always stay around 16 on squelch to keep from getting electronic interferance problems. next is the intercom setting. if the intercom is set to high it would cause the error code at times. dont know why but it did...
You have problems in the CB module or connections to the main stereo itself.
Both the Std/Tourer and I/S versions should allow you to set the squelch or intercom volumes all the way to "1" (or to "20") without faulting.
The "Er" code signifies a communications protocol fault. By that: Electronics of the day (late 90's) used various rudimentary protocols ('data languages') to talk with one another, much as today's late-model cars and motorcycles use CAN-Bus.
Clarion used a proprietary protocol known as C-Bus for intra-peripheral communications. Upon power-up, there's a "Who are you?" handshake between all connected devices. When you change the CB channel, adjust the volume and whatnot on a Hondaline CB it's done via a serial data stream - not an analog signal.
Dirty or oxidized connectors and poor grounds are the #1 source of problems in a CAN (Car Area Network), owing to the environment they're operated in. #2 is the switches in those handlebar-mounted control pods.
