C4 Climate Control Problems
Thread Starter
Intermediate
Joined: May 2004
Posts: 36
Likes: 0
From: Southern Pines NC
C4 Climate Control Problems
The climate control unit will only work on OFF and AUTO modes. No other lights will illuminate and all the AC flows out near your feet or the windshield.
So the question is... if the other lights will not illuminate is it the control head in the dash or the HVAC programmer under the dash???
Thanks
So the question is... if the other lights will not illuminate is it the control head in the dash or the HVAC programmer under the dash???
Thanks
Instructor
Joined: Aug 2003
Posts: 107
Likes: 0
From: Aurora OH
Re: C4 Climate Control Problems (NC LT4)
That's the big question. It could either be the control head or the programmer. The approved way is to use an ScanTool with HVAC capabilities to control the climate control. If it works - the problem is with the head. If it doesn't work - it's the programmer. (of course there are more than these 2 possibilities in the flow chart - electrical or vacumn potential problems).
Some folks have reported cleaning the contacts in the buttons has solved the problem - others that replacing a resistor or tightening the vacumn port connector on the programmer solved the problem.
Just a thought -
Some folks have reported cleaning the contacts in the buttons has solved the problem - others that replacing a resistor or tightening the vacumn port connector on the programmer solved the problem.
Just a thought -
Le Mans Master
Joined: Sep 2002
Posts: 8,991
Likes: 2
From: Hanger 18 Taxachusetts
Re: C4 Climate Control Problems (NC LT4)
AC flows out near your feet or the windshield.
Mine did this when I bought the car and got a good discount for it
Turned out to be a $6 vacum "T" check valve that crummbled.
It is located under the fuel rail cover (?) on the passanger side.
I also pulled the control unit out and cleaned all the contacts and checked for cracked solder joints.
Thread Starter
Intermediate
Joined: May 2004
Posts: 36
Likes: 0
From: Southern Pines NC
Re: C4 Climate Control Problems (corvette-pilot)
Actuallly, the cruise works just fine so I ruled out an overall vacuum problem. So if the programmer was bad, would that prevent the lights on the control head from coming on when you push the various buttons?
Le Mans Master
Joined: Nov 2000
Posts: 5,689
Likes: 0
From: Cape Coral, FL 33904
Re: C4 Climate Control Problems (NC LT4)
Are you getting any codes?
Here's how to check:
Push and hold the UP and Down Fan arrows, for approx. 5 sec.
The LCD should show -00
Push Auto Fan, and the LCD should show any DTC's that are stored.
Here's how to check:
Push and hold the UP and Down Fan arrows, for approx. 5 sec.
The LCD should show -00
Push Auto Fan, and the LCD should show any DTC's that are stored.
