93 600sl diagnostics

[gsxr711]

hello,
i have a 1993 600sl. the power soft top, and roll bar, have just stopped working. when you pull back on the switch, it just blinks. nothing happens. i have checked out the sl forum on this site, and there is alot of very usefull info. the blinking light should mean that there are codes stored in the control module for the soft top. my question is , can i retrieve the codes myself, or do i need a special scanner? the connector under the hood, on the passenger side, looks to be round. any info, or suggestions would be greatly appreciated. thanks