Tally TransAm

iTrader: (17)

I have a 1999 TransAm with an 01 operating system in the pcm. i have the wideband input for my lc1 hooked into my ac pressure sensor so i can monitor my wideband with hpt.

the problem that i am having is that the fans are always on from the moment i start the car and i have a strong feeling it is from the ac pressure sensor seeing the wideband voltage and commanding the fans on

is there any way to correct this. i see in the hpt help section there is a Desired Fan % vs AC pressure parameter but i do not believe i have the ability to edit this

any help?

WhiteRhino

iTrader: (6)

Not sure if this helps, but couldn't you just wire it into the egr input on the pcm. That way you don't have to mess with the ac. You should be able to still enable egr in the 01 os I thought. Thats how truck guys do it even though they don't have egr. Not sure of the pin number on the pcm, thought it was pin 41 though. Then you just log the egr voltage pid as well. That's how I have my Afx wired into my 98. I had egr though, so I just tapped into the brown wire in the plug.

I know this doesn't really address your problem and i'm not sure the solution. Just throwing the egr source out there.

Tally TransAm

iTrader: (17)

im gonna end up going through my egr if i cant figure this out. i just dont really feel like rewiring it after i got it all nice and neat

aram

iTrader: (7)

I am having similar problems I'm working on fixing right now. I'll post up if I find out what it is.

If you get a chance though try to cut the a/c wire and see if the fans turn off.

I thought my fans turning on was a glitch in my program somewhere so I put a new modified stock bin on and it seemed to stop. I'm not sure what I changed. I messed with some of those a/c tables.

I put my old bin in just now and the fan kicked on at 150 deg. I cut the a/c wire and they shut off.

I'm switching it to through the EGR input I think. It's easier to shut off the EGR in the pcm.

aram

iTrader: (7)

Ok, you can probably make the A/C not request the fan by playing with some tables, but I just wired it through the EGR right now. I also noticed there was a little noise on the a/c signal wire and I got a flat signal through the EGR.

you have to turn on the EGR in your tune.
I used PID 2811 for the output voltage
it's the brown wire on pin 55 on your blue pcm connector

also make sure any of the EGR spark/fuel? corrections are zeroed out so there are no unintended side effects of doing this.