Over the years I've owned several Caddy's: 84 Eldorado, 86 Fleetwood, 90 Eldorado, 94 STS, & a 96 SLS. All had the On-Board diagnostic thru the HVAC controls.

Just the other day I found an 07 STS V8 on eBay and it had a 'buy it now' price that I couldn't res... Login to read more.