: When did they start "diagnostic mode"?

08-23-05, 12:47 AM
I was always curious when Cadillac started equipping their cars with the on board computer diagnostics aka Diagnostic mode? I thought they came out with it in the 85-93 era devilles/ fleetwoods, because i've never heard of it in anything else, but i was talking to adumbfive and he told me hes got it in his '83 FWB, which i thought before was too old to have that, but i was wrong, i learned today they have it also in the pre 1992 Broughams also. So what are all the cars that have it? and when did they start it? I'd think somewhere around 1982 when they first started to install the fuel data center.