I have a 94 Concours just did an engine replacement and found that the fuel injector harness got very hot at the plug into the main loom. I rewired the porblem and put in the engine now I have a rough idle and 2 OBDII codes 52 deffective ECM, and 109 PCM lost primary battery power. Can anyone help me with this?

 

The 94 was OBD-I not OBD-II.... But anyway, did you swap PCM's with the engines?.... I think I heard somewhere that you need to keep the same PROM chip with each engine... I'd have to look it up as I'm not sure though.

 

Krashed I did use a prom chip from the doner engine. Can you think of any thing else. How can I check if it has lost primary battery power?

 

Wait... LMAO I just looked up those codes for myself. You have nothing to be worried about.

P052 (E052) ----- PCM Memory Reset
This is from the battery being disconnected while you were swapping engines

P109 (E109) ----- Keep Alive Memory (KAM) Reset/PCM has lost primary battery power
And this is also from the battery being disconnected.


All you have to do now is drive it around. After a few drives it should relearn the idle automaticly and you'll be good to go.

 

Krashed,

Thanks for the info. We have put on about 40 miles already. How many miles do you think it takes for it to relearn????

 

Miles don't matter... What matters is key cycles. Turn it on, go for a short drive, then turn it off and repeat... If that doesn't help you'll have to do some further diagnosis

 

Krashed,

Again, thanks for the help and I'll give it a try. I'll let you know if I continue to have the problem.

 

Those codes have no effect on the engine sytems.
Just letting you know the pcm lost power since the last time the codes were cleared.

A rough idle is a vauge description.

Can you narrow it down to an individule cylinder?
Does it seem like a misfire?
Does it drive smooth?

 

To me I thought that it could be a bad injector because I had to rewire the connector I really took my time doing so though. The part was over 700.00 at Cadillac. iIt will drive really good but then when you slow to a light the idle drops too low and starts missing I cant be sure the cylinder because it does not have a misfire code.

 

There is an idle relearn procedure... But I'm at college right now so I can't look it up in my FSM at the moment.

Just out of curiousity, does the ICM "click" repeatedly after you turn the engine off?