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2002 SLS HVAC - system "dead".

1124 Views 6 Replies 3 Participants Last post by  basscatt
Hello all

I have a problem with the heater of my car. The heater will not respond to any controls except the fan. I can change the modes on the display but the mode doors will not move. I can change the
temp on the display but the blend doors do not move.

I took off the battery cables and touched them together let the car sit overnight with the battery
disconnected. I reconnected the battery started the car up and none of the HVAC controls work.

I took the control head out of the 2001 SLS parts car and installed it in the 2002 sls and it does the
same thing has no actuator movement. I tested the 2001 before removing it and it seemed to work

During all this there has been no HVAC codes.

Thanks for any help, Joe
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I have checked all the fuses under the back seat and under the hood and they all check out good.
I tried to check codes with my OTC genisys and it will not access the HVAC module I checked codes with the car and it
finds one p code po480 for cooling fan circuit one. It also has two b codes b3833 and b3832 for the doors.

I pulled the cabin air temp sensor on the drivers side and the fan does not run.

I have ran the temp up to 90 and down to 60 and the display works perfectly but the blend doors do not move.

I pulled the glove box out and can watch the recirc door and it doesnt move.

The car is sitting inside the shop right now so it is plenty warm.

I think I will get an alldata subscription, then I can pin check and see if I have a actuator that is grounding out and I can also load test the powers and grounds.

Any advise is welcome, Joe
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I figured out the problem with the HVAC last week and I figured I would post the solution in case anyone else runs into
this problem.
The brown 12 volt power wire that powers up all the actuators and the cabin air temp sensor fan was corroded under
the fuse box. That fan should run anytime the key is on with the heater control head hooked up or not.
Hopefully this will help someone should they run into the same problem.
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