1987 Cadillac Hearse ECM/ECU which software?

PRODISCO

MEMBER
1987 CADILLAC HEARSE
V8
FWD
AUTOMATIC
92,000 MILES

Hi looking for details for an ecu/ecm for my car. I am based in the UK and have a 1987 Cadillac Hearse (s&s Victoria) vin no: 1EGDZ9085H4221090
the Log details call it a Fleetwood but the vin classes it as a Brougham on a commercial chassis, it's a 4.1ltr FWD, just imported in the UK - & sent into the garage for a service (new filters,plugs,dizzy, etc.) now it's not running right, and the mechanic thinks it may be the on board computer. The Uk mechanics are not familiar with the system, and don't have any software to diagnose faults...! I suggested running a flash code test on the aldl and clipping A+B together, even giving a printed sheet with how to do it, all I got was " ...beyond us mate!" I think I need to access a proper diagnostic, so I could do with knowing which one it is please. I think it may be 1227056, but I'm not shure. Please, please can you help, do I need to replace the ecm alltogether, any help would be most appreciated. Thanks in anticipation, Andy Mcknight. Blackpool, Lancashire

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Your first problem is it's a 4.1L those are junk engines, they have loose liners for cylinders and LOVE to blow head gaskets. Check for that first. To get your codes, take a peper clip and go between A & B turn the key on and the service engine light will flash. It will flash 1 then 2 three times each. That means a code 12 = normal. Then other codes will flash. You can come back to the site here and on the left of the screen under popular site links is trouble code definitions. Go to GM and look under OBD1 as that is the system you have. I doubt it's the ecm, but not saying it could be. Also if your battery is in poor condition it will cause all kinds of computer problems. If the battery reads 12.3 or similar with a digital volt guage after being charged, then replace the battery if hte alternator is charging ok. Your mechanics sound like a lot of us guys when it comes to foreign cars lol.