[Motorola] Spectra fail code 08/10 option serial bus failure

[d.stiver at att.net]

I have a high power uhf spectra that I purchased on ebay. I was able to program radio on 440-470 frequencies. However the radio has intermittent xmit and receive do to failure 08/10. My manual states option bus serial failure, see spectra 9000 siren/pa option manual. I do not have this manual. I went into control hd in program mode and turned off all siren functions. Code still there. Also tried different con head. Still no luck. HELP! Don K7LHR