c4/c5 or others hvac problem help

[LT1driver]

03 zo6 with 55k on it...air blows cold, problem is when I adjust the temp from 60 to 68(or more) and then try to go back to full cold (60) the air won't cool back down and blow cold, vent temps stay where they were, ex 68. if I turn off and let sit for a few hours and put control to 60 it seems to stay there ok.....control head, door actuator??? thanks.

[c4c5specialist]

HI there,

What, if any, DTC are in the HVAC ????

Althebest, c4c5

[Junkman]

Good ol' AC fun. Subscribed.

[LT1driver]

c4c5....no codes current or stored and can't remember any hvac codes in recent memory..thanks for your help

[Junkman]

If you went and pulled your codes right now, you're saying there are none, current or history? This on first thought sounds like a actuator problem as they control the doors that open and close, allowing heat or cold air to be delivered to the vents. However, the actuators must be sent a signal to make that move and that is sent by the head unit. Try this. Perform a actuator reset.


Re-Calibrating Actuators
Use the following steps to perform the calibration update:

1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module (fuse #27). This fuse is located in the passenger's side floor board area.

Important
The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.


3. Wait 60 seconds.
4. Install the fuse.

Let us know what happens.

[LT1driver]

junkman, will try that this weekend when I drive the car