I changed my ecm today. REplaced the prom with my old one. The old ECM was bad, found out trying to set the timing. The new ECM turns on the Check Engine lite. I jumped the A and B connector but the Engine light did not flash.

I bought a code reader from Wal-Mart, (Don't waste your money on this, it is basically a jumper wire in a box for $20.) and still not flashing fo the engine lite.

HELP!!!

By the way the car runs good but according to emissions test is running rich. It is an 85 Berlinetta carbed.

 

Strange thing aint it? I have the same problem with my 89 GTA, Ive searched and read through hours of material and the most I could dig up is that the ecm is bad.

My car has a remanufactured ecm in it that the previous owner put in. I did find that there is a fusible link leading the the positive battery terminal for the ecm that could be bad and theres an ecm fuse near the batt somewhere that could be blown, unfortunately mine are good.

My ecm fuse was forward of the battery behind my driver headlight.

My car runs ok considering the loping idle and it too runs VERY rich, I consider it undrivable though..

 

Did you check the ECM fuse under the dash? 99% of the time its either a blown fuse or toasted ecm.

 

Where is the ECM fuse? Is it in the panel with all the fuses?

Does this sound like a fuse problem? The old dead ECM wouldn't lite the "check Engine" lite or control timing advance. The new ECM lites the lite and it stays lit. When I jump the A and B terminals the lite just stays on. No Flashing

 

Must be in the fuse box with the rest of the fuses.. Worth checking

So theres an ecm fuse under the hood and under the dash? 2 ecm fuses or possibly more?

 

Why yes there is 2 ecm fuses johnny! Both mine are good.

Im guessing the ecm is toasted.

Could the wrong prom/chip prouduce these symptoms me and guza are having?

 

I haven't found the fuse behind the headlight yet! Haven't had a lot of time to look! The fuse in the panel is good though.

 

Well I swapped in a known working ecm thats correct for my car and the problem didnt change.

Perhaps we're looking at bad proms, I have good ecm fuses, didnt see burnt fusible links and a good ecm.

I have a prom that starts ANYY and people here on Thirdgen.org arent familiar with it.

I have another question hopefully some knowledgable people will come forward and answer, if the prom is bad or incorrect would the ecm be unable to flash codes and light the SES light continously without the engine even running? Could the ca operate in closed loop mode without a correct or bad prom?

 

Well, I was able to finally look at my car and found that the ECM fuse in the panel was bad. Replaced it and now teh check engine light is out. Got too late to see if it flashes. I'll try to check that later.