I got trouble with my -02 Suburban
The heater dont work in auto mode. I select 23C deg but blows only icecold air.
If i chose the max het level 32C deg then i get nice heat but its not possible to go on that when it gets to hot in car.
No fault codes when i read with my AutoTap reader. Whats next step to try?

 

Did they put the serial bus or data bus on this truck electrical system ? I though the 02 was a serial bus.
you wont get fault codes from a reader for the heater. could be the switch itself, but from your post your saying you have specific temp selections on the environmental switch. almost sounds like a data bus control. kind of throws me what GM does sometimes. could be a sensor under the hood but you would have trace it with a meter. if its a data bus its going though the BCM which makes it kind of hard for a trace but can be done. find out if you have some sort of senor under the hood or dash. My guess would be the dash near the heater core on the right side. Most 01 and 02 Suburbans have just the dial switch with a red blue marks on it that is control by the switch itself for the heat direct to the core.


I would first run a vin and find out what option are installed in this truck. it would tell what kind of electrical system you have or if your enviormental controls are digital or analog. You could try the online vin checks. but i don't think they get that detailed. you could go to the dealership and have them run a vin tell them to bring up the parts for the environmental switch, it will show a diagram with the parts in that specific list. see if there is a sensor there. If so can't be much even from the dealer. You have switch problem or sensor problem here.

 

Thanks for your reply. I dont have any chevy dealer in close The one that was here dont even sell spareparts to GM any more. Chevy signs still hanging up but they only serve and sell KIA now Looks like Sweden is falling down to drive small China made cars.
My cars VIN 3GNFK16Z73G205919 if its possibly to check up some way. Feels like its data bus and something spookey in that one because today my remote locking control dont work and the seat heter changes powerlevel by its self.
Some way to reset the data bus?

 

here is link to decode your vin number ,

http://service.gm.com/dealerworld/vincards/

select your year, pdf will load up, then decode your vin number. match the numbers and letters with what on the pdf for the options installed in your truck.

found out you truck was made in Mexico.

I have had time to go though this yet.

 

I tried compnine for your vin. they are out of business now. do you have a digital readout on your temp or is it a dial ? Im just. trying to determine what is in your Euro Z71. some trucks that went to Europe are have different option than the trucks made in Mexico and the USA. A good example is the turning headlights. Most Z71 that went to Europe have this option, but you wont find that option in most US and Mexico made trucks bound for the USA. Europe has a different standards they go by for safty and environmental including the AC.

 

My Z71 has an digital display that shows temperature and air direction adjustments etc. Right and left temp selectors and bouth sides blowing cold exept from when i set temp to max.
The car is exported as used from USA or Canada ( I dont remember how it was told from the owner before me).