i have the 1228747 HD ecm in my chevy K5. i had a company trying to tune chips for me and they couldn't get it running very well. so i ventured out and have started tuning for myself. now i totally understand why they couldn't. there's no way to know what to do without having the actual vehicle.

anyways, they had a burn for me that allowed the ecm to up the idle when you'd turn the a/c on. i would like to have it bump up the idle by about 200 rpm since my a/c compressor is now converted to on board air. but in the $4F mask i can't find any a/c controls for the 8747 ecm....is there another mask i can use?

what do i need to change in the chip to get the idle to come up?

winaldl comes up with "no a/c requested" but i don't know how to change that.

im using tunerpro, if you can help me out

 

Looks to be this value:

LD5ED FCB 0 ; DIFF RPM FOR A/C ON (RPM/12.5)

A/C status input should be on pin B8. Set +12 volts to it to change the A/C status.

RBob.

 

in the constants or the table values? i can't find it in either one...

 

If present it would be in the constants as it is a single entry. As it isn't there you need to add it. The ECU & XDF files don't include everything. There are hundreds of parameters in the calibrations.

RBob.

 

i have to idea how to add definitions... can you help? step by step maybe...

 

Check Mark's site (www.tunerpro.net) for a tutorial. There used to be one on his older site. I know that there has been some info posted here on how to create an XDF entry.

RBob.