I just installed a new used PCM with basic programming (early fan turn-on, CAGS eliminated, etc) that I got from Ion (www.madtuner.com) and I decided to scan it on my EASE scanner since I got an SES light right off the bat. I then decided to just clear the DTCs since they may have been from the previous owner's car (it was code 0122...low value seen on TPS).

Anyways, my TPS readings looked fine but my calculated load at idle was just showing 47-50%!! I noticed that my idle is a little rough but it may have always been that way. When I revved it, it went up above 50%...

What gives!? I'm gonna play with it more tomorrow to see if I get the same thing. How is the PCM calculating this load anyway? Off the MAP sensor? Any pointers???

Thanks...

 

What was the reading before the new PCM? What modifications have been done to the car? A poor idle is going to skew some results.

 

The reading used to be 2 or 3%. The idle was definitely rough...no mods to the car other than 160 degree t-stat, and that's been there for a while. But I drove it to work this morning with the laptop hooked up and everything was fine. Plus my idle smoothed out. Load is back at 2-3% at idle. Car must have been running rich and advanced when it thought it had a 50% load at idle...

Maybe it was a PCM learning thing? I'll have to keep an eye on it. The good thing is that my fans must be coming on now as my temp didn't get above 189...and it's 80 degrees outside. The whole reason for the PCM was to get the fans to turn on...and it seems to have worked. Must have had bad drivesrs in the PCM...not that I know what they are :-).

So hopefully this was a fluke.


Thanks

Sean

 

It does take a little time for the PCM to relearn idle.

 

What does your MAP reading look like at idle? The PCM uses MAP as an indication of "load".