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Does anyone know anything about spark plug decoders? Or the ESM... little black box wired to the distributor? Apparently California manufactured caddy's were the only ones with this! My caddy won't start and when I unplug this box, the car will start but idles high and stays there! Is there a way to remove or bypass this ECM/ESM? Please help! 

Edited by los 49ers

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ESM - Electronic Spark Module.

I think it's a knock sensor, although I'm not sure why it is not allowing the engine to start, I'm guessing it is grounding the circuit. From the symptoms it seems the distributor is in full advance when it does start. 

Without a schematic I wouldn't be able to do a work - around.

Just for an experiment - with the ESM disconnected, set your distributor to base timing and see if it will allow a more normal idle. You will need a timing light to do this. Note your timing when you start so you have a target to go back to if it doesn't work.

If you have a Factory Service Manual  send some pics of the circuit. 

Wait for @BodybyFisher he has a source for nationwide used parts.

Edited by OldCadTech

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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I'm about 3 - 4 hrs south in Long Beach.

Hmmm, probably more like 4-5 hrs, I thought you were closer to Bellingham....

Edited by OldCadTech

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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Here is a searchable nationwide database of scrapyards

Http://www.car-parts.com


Pre-1995 - DTC codes OBD1  >> http://z-cut.de/US/dtcobd1.html

1996 and newer - DTC codes OBD2 >> http://carprogrammer.com/Z28/PCM/OBD2/On-BoardDiagnosticTroubleCodes(OBD-II).mht

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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