ill put it on MAX ac and be driving then switch it to vent/feet and it will stay at max ac setting, i can change it to anything defrost, defrost/feet and it will stay at max ac. i have to turn off the truck and take the key out to make it work right. it doesnt happen all the time, what is wrong?

2006 4.2l

 

I have of 06 4.2L as well. On my truck, which is an XL, I have all manual controls. As part of that, I have a MAX button that I push and it will recir. no matter what vent setting I then change it to.

 

Sounds like the EATC module itself. There are diagnostics that can be run if you have EATC.

 

yes, i have a XL manual also. i have a recir button but not a MAX button, just a a/c button and recir button.

whats EAtC?

 

Can you please elaborate on the process please for diagnosing.

I'm pretty sure my EATC needs to be re-built from the other thread going on but i'd like to know for my own general knowledge