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identify bcm


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Discussion Starter #1
92 DEVILLE, Code F32
Can still start onboard dionostic and get only F32. Dionostic system will not advance beyond 7.0. Disconnected batt. and got the system to reset.
Everything seemed to return to normal, but after driving one block, same problem returned. Now will not reset when batt. disconnected. I have Cadillac shop manual, and it says bcm and pcm are not talking to each other as they should. Book says check the circut to and from bcm and pcm to look for open or ground. Help on that procedure !!!!! I have access to local yard with plenty of
91 thre 93 devilles and warrent their computers, and have cheap cost. Might just try replaceing both units. Just need to know how to identify the replacement ones so I will get a correct match.
 

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99 Seville STS, 08 STS4 N* 1SG F55
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If you have the FSM it should have a proceedure to verify BCM-ECM connection. If you want to swap from a yard, pull your old one and look at the part number and match it to a new one. Since you have an F code it could be the BCM. I'd start with that first because you can usually change it in 20 minutes after the first six-pack.
 

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Discussion Starter #3
Thanks,
I have the PCM out but still attached. Working on BCM removel. Long trip to yard with about 15 91 thru 93 Devilles to try to find match. Should be able to find match. I get a Prom broadcast code of 500 on the dianostic system.
Book shows where to check code on Prom. Doesn't seem to match. Car has been running great, until this computer glitch showed up. I'll let you know if
replaceing the BCM does the fix. Will try BCM first and if that does'nt work, I'll add PCM replacement, and try. Will also try to find Prom to match.
Thanks again,
Stumped
 

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99 Seville STS, 08 STS4 N* 1SG F55
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It may not have to be an exact match either. I put a BCM from a 92 into my 90 and everything was fine except it would throw an F15 code on diagnositics. Since the 90 FSM didn't have a listing for F15 I assume it was something that the 92 had and the 90 didn't - either way it never caused a problem.
 

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Discussion Starter #5
What #'s on the PCM + BCM should be used to used to get a match. There are several #'s on the outside of the cases along with Prom #'s inside.
 

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99 Seville STS, 08 STS4 N* 1SG F55
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The two I have from my 1990 have tags on them that say Serv. No. 16130754. The next line says 875366 followed by an M with 9 more digits that I believe are the serial numbers as they are different on each unit. There is a separate tear-off tag with 16135366 on each and a bar code of the serial number line. I would go by the first line to interchange and I believe anything that uses the same plugs should work.
 

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Discussion Starter #7
Found exact match BCM + PCM(ECM) Still getting Check Veh Soon warning light
but it comes and goes. Still getting Check eng. warning and it does the same.
Car seems to be operating as it should. Second problem is the dianostic are still only working to point of showing F32 (current code) and F32 (history)
If I clear them and start dio again, they come right back. The dio system will
not go beyond startup and checking for codes and showing F32 and FF32 then 7.0. If I try to press the low button, it does not advance the dio system. Seems to be stuck at that point. Tried unpluging MAXI FUSE #4 under hood as book says to reset computers, but that hasn't worked either.
Anyone have Bill Gate's phone #
 

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Discussion Starter #8
Found out cruise switch has to be on to enter dio. Works ok with just key
on but still won't work after starting engine.??? I know Get a bigger hammer.
Any suggestions.
 
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