What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Doubeleive

Wes
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currently troubleshooting a b0168-05 hvac problem, the definition being open/shorted circuit to rear temp sensor 2 meaning it is reading -32deg or+450deg for more than 15 seconds which is supposedly the one going up to the headliner, however the existing sensor test's good (resistance test) and the harness has 5v like it should. another definition says that b0168 is basically a fault when nothing else can be defined????? so another related issue is the rear hot/cold temp blend door moves to cold when commanded hot with the tech2 and it moves to hot when commanded cold weird? it also only moves to hot when commanded to 90deg on the digital control otherwise it stays on cold. so the door actuator is $123 and I have to go pick one up and see if that corrects the problem either the actuator is bad or something is commanding it wrong. there is little to no information on this without going thru some other probably complex test procedures which require a subscription-yay
 

Rocket Man

Mark
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currently troubleshooting a b0168-05 hvac problem, the definition being open/shorted circuit to rear temp sensor 2 meaning it is reading -32deg or+450deg for more than 15 seconds which is supposedly the one going up to the headliner, however the existing sensor test's good (resistance test) and the harness has 5v like it should. another definition says that b0168 is basically a fault when nothing else can be defined????? so another related issue is the rear hot/cold temp blend door moves to cold when commanded hot with the tech2 and it moves to hot when commanded cold weird? it also only moves to hot when commanded to 90deg on the digital control otherwise it stays on cold. so the door actuator is $123 and I have to go pick one up and see if that corrects the problem either the actuator is bad or something is commanding it wrong. there is little to no information on this without going thru some other probably complex test procedures which require a subscription-yay
Oh fun
 

Doubeleive

Wes
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well for future reference this rear sensor is supposed to be in the left rear headliner near the rear hatch, but apparently I do not have this option, I am now thinking my issue is stemming from the front hvac control I replaced this summer and that it needs to be flashed for my truck even though it shouldn't have to be.

roof.JPG
 

Doubeleive

Wes
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I'm no help on the NNBS. My Silverado doesn't have rear heat...:(
well it was a afternoon of learning for me, I spent a $123 for a part I didn't need (maybe) and found out there is at least 7 interior temp sensors, 4 upfront, 2 in the back and one in the headliner by the driver (and optionally the rear headliner) making it 8, not including the daylight sensor which apparently has something to do with it all. put it all back together and I will have the dealer flash the hvac control on Monday if there open because I am now pretty sure everything else is working properly and that has to be the issue.
 

Rocket Man

Mark
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well it was a afternoon of learning for me, I spent a $123 for a part I didn't need (maybe) and found out there is at least 7 interior temp sensors, 4 upfront, 2 in the back and one in the headliner by the driver (and optionally the rear headliner) making it 8, not including the daylight sensor which apparently has something to do with it all. put it all back together and I will have the dealer flash the hvac control on Monday if there open because I am now pretty sure everything else is working properly and that has to be the issue.
:eek:
 

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