1986 Oldsmobile Cutlass electronic control module

HEMIH

MEMBER
1986 OLDSMOBILE CUTLASS
V8
2WD
AUTOMATIC
95,900 MILES

I went through a large puddle recently and my service engine soon light came on and stayed on.I checked eveything under the hood and could find nothing wrong.I attempted to clear the trouble code by disconnecting the negative battery terminal for 10 seconds, and this did not clear the service engine soon light.I had my friend hook up his scan tool and it would not diagnose the problem. Is it possible that I shorted out my ECM when I went through that large lake type puddle.

Tuesday, March 23rd, 2010 AT 10:38 AM

3 Replies

JDL

MECHANIC
16,098 POSTS

Besides the check engine lite, are there any driveability issues? I was just curious, did you try the jumper wire techinque to access mil codes?

I haven't looked at wiring circuit for your mil. If you unplug that circuit from the ecm and the lite stays on, I don't think the problem is the ecm. Think positive.

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Tuesday, March 23rd, 2010 AT 11:29 AM

HEMIH

MEMBER
2 POSTS

Thanks for the reply. I have attempted the jumper method, I believe putting a paper clip into the A and B terminals of the ALCL should give me a code 12 three times, indicating the diagnostic circuit is ok, then the trouble code should avail itself by a series of flashes and pauses but I may be wrong on this one. Please let me know if I am. My attempt using this method revealed nothing. As far as driveability issues are concerned, the only thing I've noticed is that the emission odors are a little stonger than before, and it does'nt idle high when I first start it up in the morning like it used to, then I'd kick it down. Also I can't hear it going into closed loop like before, and I don't hear the mixture control solenoid ticking in the carburetor like it used to.

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Tuesday, March 23rd, 2010 AT 12:19 PM

JDL

MECHANIC
16,098 POSTS

I believe you used the jumper correctly? Between A & B terminals, key on, no crank. It wouldn't even flash a code 12?? In the past, I couldn't get a paper clip to work, so I used a piece of automotive wiring and it worked, then. I don't know why it wouldn't work with the paper clip, for me? I found this wiring info for the mil, cutlass supreme. Part of the troubleshooting info below, didn't quite make sense to me? Maybe it will help you?