BCM or wire?
A/C funny business
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BCM or wire?
#1taho
5150TAHO
BCM
Almost everything inside is controlled by it. with as many problems as you are having it's a good place to start. Please let us know how you make out.
Almost everything inside is controlled by it. with as many problems as you are having it's a good place to start. Please let us know how you make out.
Thanks, will do.
Ok time for an update.
Bought a used BCM, had a local shop install it and wait for it.....
....absolutely no change.
Got to the point were I considered selling it. Found an 08 Escalade for a fair price, love the engine and transmission but it had almost the same problem as my car. A/C and seat heaters didn't work.
Guess I'm just not meant to be cool.
Back to the drawing board.
Bought a used BCM, had a local shop install it and wait for it.....
....absolutely no change.
Got to the point were I considered selling it. Found an 08 Escalade for a fair price, love the engine and transmission but it had almost the same problem as my car. A/C and seat heaters didn't work.
Guess I'm just not meant to be cool.
Back to the drawing board.
I'm not willing to give up on this. Now I'm thinking the problems might not be connected. So if I look at them as individual problems.
Front HVAC.
1.AC doesn't turn on if outside temp is lower than 68F
2. Will not cool or blow cold unless I set HVAC to coldest setting. If set on auto theres Lot of difference between the lowest setting and a degree above lowest. Fan motor won't increase speed until it is set to the lowest temp and blow relatively cold air .
3. To maintain a comfortable temp and not having it blowing hot air all the time I need to set it at 60-63 degrees.
Scan tool reveals no DTC or problems.
Solutions:
1. Maybe interior ambient sensor is faulty or off calibration. Outside ambient temp seems to be working fine. At least the temp shown in the mirror are about right.
2. Wiring is shot or worn.
Rear HVAC.
Won't change modes or temp setting. Fan motor works fine.
Solutions
1. After changing the control module and actuator I think that only leaves a problem with wiring or the whole assembly needs replacing like one of the shops suggested.
Thats all for today.
Front HVAC.
1.AC doesn't turn on if outside temp is lower than 68F
2. Will not cool or blow cold unless I set HVAC to coldest setting. If set on auto theres Lot of difference between the lowest setting and a degree above lowest. Fan motor won't increase speed until it is set to the lowest temp and blow relatively cold air .
3. To maintain a comfortable temp and not having it blowing hot air all the time I need to set it at 60-63 degrees.
Scan tool reveals no DTC or problems.
Solutions:
1. Maybe interior ambient sensor is faulty or off calibration. Outside ambient temp seems to be working fine. At least the temp shown in the mirror are about right.
2. Wiring is shot or worn.
Rear HVAC.
Won't change modes or temp setting. Fan motor works fine.
Solutions
1. After changing the control module and actuator I think that only leaves a problem with wiring or the whole assembly needs replacing like one of the shops suggested.
Thats all for today.
Now things have changed quite a bit. I borrowed a Tech2 and I've found that AC permission was witheld. Hopefully granting it permission again will get rid of that problem for good.
The only DTC I had was in something marked RCC. Which I believe is the rear climate control module.
Maybe the new module doesn't work properly because it wasn't installed with tech2 in hand. Still have the old module I'll try using that again.
The only DTC I had was in something marked RCC. Which I believe is the rear climate control module.
Maybe the new module doesn't work properly because it wasn't installed with tech2 in hand. Still have the old module I'll try using that again.
rockola1971
Full Access Member
If you have automatic climate control it sounds like you need a new one. The temp sensor could be junk as well.
Rear HVAC module may need just reset. Pull positive lead for 10 mins, touch the positive lead to negative lead for a few seconds, reattach positive lead to battery. Start vehicle but make sure all controls are set to off first. Set AC on auto (if equipped), turn rear air on and the module will recal all blend motors and vent motors. There are some modules that have been updated with a new part #. Module is underneath trim at passenger side rear cargo area window. Forward of evaporator.
*Note* rear AC module is controlled by BCM.
Rear HVAC module may need just reset. Pull positive lead for 10 mins, touch the positive lead to negative lead for a few seconds, reattach positive lead to battery. Start vehicle but make sure all controls are set to off first. Set AC on auto (if equipped), turn rear air on and the module will recal all blend motors and vent motors. There are some modules that have been updated with a new part #. Module is underneath trim at passenger side rear cargo area window. Forward of evaporator.
*Note* rear AC module is controlled by BCM.
