Strange Climate control behavior. Temperature sensor maybe?

[Farking Bastage]

I've already combed through the stickies and this doesn't seem to fit the common DCCV issue described therein.

The temperature control on my '03 LS has gone a bit wonky, and I'd like to get some ideas on where to start.

Basically, if you set it on a middle of the range temperature ( really annoying on defrost) it will either go full cold or full hot. However, it is equal on both sides of the system( haven't really tested putting one side on hot and one side on cold). I'll kick the defrost on in the morning at, say 72 with an ambient air temperature of around 80 and she blows full on cold. If I start adjusting it up, it will continue to blow full on cold until I hit the top range of the control at 90, then it blows full on hot. This behavior is also duplicated if I start it on hot. I can move the temperature down and it continues to blow hot until I hit the bottom range of 60 then it goes full on cold.

Basically, I have no mid-range in climate control anymore.

Could this possibly be:
A sensor of some sort?
Cabin air filter?
Low on coolant, but not low enough to totally freeze up the evaporator?

I appreciate any ideas on this.

Thanks

 

[LS4me]

I would still suspect the DCCV.

 

[Farking Bastage]

Would the fact that it eventually adjusts mean that it's not completely failed, just "sticky"?

Not a rhetorical question.

 

[joegr]

I won't repeat my previous replies. I will say that shorod may be right about the temp sensor.

If it were my car, I would connect my scan tool and look at the live sensor data for the climate control and see if the reading looked rational while it was acting up. If so, the sensors would be ruled out. If not, then replace the one(s) that isn't right.

If I didn't have a scan tool that gave live data, I would start by replacing the DCCV. If that didn't fix it, I still wouldn't feel too badly about it. The DCCV is one of those things that either is failed/failing, or is going to fail.

Short of replacing the DCCV, you could get a close look at and see if it looks like it's been leaking or is corroded.

 

[joegr]

Would the fact that it eventually adjusts mean that it's not completely failed, just "sticky"?

Not a rhetorical question.

It's also possible that if you have an early 03 model it may still have a cold-air bypass door. If that is the case, it could be that your DCCV has fully failed and the bypass door is activating when the DATC calls for full cooling.
(Cold air bypass doors were eliminated by 04.)

 

[Farking Bastage]

Thank you guys. I'll start with the fuse and go from there.

You're a damned helpful bunch, you know that?