Help diagnose AC / Heat problem

[gregsmy]

I have a 2010 Suburban with the dual zone climate control. Lately since the temperature started to change I notice that sometimes the blower sound will be very loud near the passenger side air bag and outside at the cowl. It also seems to blow less strong at the vents when this happens. I typically operate it in the manual mode without the passenger control on. Basically I will be driving and everything is operating normal and then I notice it getting louder inside and less air coming out of the vents. Sometimes I can adjust the temperature and it goes back to normal. I tried resetting it by pulling the fuse and that helps, but eventually it goes back to the same problem. I operated it this morning to test the operation of the temperature and passenger controls and that seems to operate normally. Its kinda random but I think it has to do with the temperature. I see that there are issues with the actuators but not sure how to figure out which one it would be. Any help would be appreciated.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this area will chime in.

@swathdiver

 

[swathdiver]

I have a 2010 Suburban with the dual zone climate control. Lately since the temperature started to change I notice that sometimes the blower sound will be very loud near the passenger side air bag and outside at the cowl. It also seems to blow less strong at the vents when this happens. I typically operate it in the manual mode without the passenger control on. Basically I will be driving and everything is operating normal and then I notice it getting louder inside and less air coming out of the vents. Sometimes I can adjust the temperature and it goes back to normal. I tried resetting it by pulling the fuse and that helps, but eventually it goes back to the same problem. I operated it this morning to test the operation of the temperature and passenger controls and that seems to operate normally. Its kinda random but I think it has to do with the temperature. I see that there are issues with the actuators but not sure how to figure out which one it would be. Any help would be appreciated.

The best way to determine what is wrong is to put a bi-directional scan tool on it and scan for trouble codes and see if the actuators are meeting the commanded numbers. Having said that, I think your recirc actuator needs replacing. Even if you replace it yourself, you still need to use a bi-directional scan tool to re-calibrate all of them.

The recirc and passenger temp actuators are easily replaced by pulling the passenger side airbag which in itself is also an easy job.

 

[gregsmy]

The best way to determine what is wrong is to put a bi-directional scan tool on it and scan for trouble codes and see if the actuators are meeting the commanded numbers. Having said that, I think your recirc actuator needs replacing. Even if you replace it yourself, you still need to use a bi-directional scan tool to re-calibrate all of them.

The recirc and passenger temp actuators are easily replaced by pulling the passenger side airbag which in itself is also an easy job.

Thanks for the information. I will look into those two actuators. I have had the entire dash out before to repair the cracks and am familiar with the air bag removal. If I replace the recirc actuator, will it recalibrate on its own if I ado the fuse pull trick? I don’t have a tech 2.

It does sound exactly like the recirculating is happening when it gets louder. I don’t operate it in the Auto mode, so it seems kinda strange that the controls would try to change it while driving. Would the non auto mode use the recirculating to adjust temperature? On most of my other vehicles I tend to leave the ac on recirculating mode all the time, but the burb won’t let me do it.

 

[swathdiver]

Thanks for the information. I will look into those two actuators. I have had the entire dash out before to repair the cracks and am familiar with the air bag removal. If I replace the recirc actuator, will it recalibrate on its own if I ado the fuse pull trick? I don’t have a tech 2.

It does sound exactly like the recirculating is happening when it gets louder. I don’t operate it in the Auto mode, so it seems kinda strange that the controls would try to change it while driving. Would the non auto mode use the recirculating to adjust temperature? On most of my other vehicles I tend to leave the ac on recirculating mode all the time, but the burb won’t let me do it.

Yes, has to calibrated with a Tech-2. As to your second question, not sure. But a wandering actuator will do it.

 

[gregsmy]

Yes, has to calibrated with a Tech-2. As to your second question, not sure. But a wandering actuator will do it.

I am all for buying a Tech 2. How steep is the learning curve to be able to use it? I replaced the transmission TECHM and paid a local shop to flash it to my vin and do all of that. I was going to buy a Tech 2 at that time and the subscription for my vin but was worried I would brick it.

 

[swathdiver]

I am all for buying a Tech 2. How steep is the learning curve to be able to use it? I replaced the transmission TECHM and paid a local shop to flash it to my vin and do all of that. I was going to buy a Tech 2 at that time and the subscription for my vin but was worried I would brick it.

It's pretty intuitive, especially if you use it with the shop manual. GM/ACDelco made the Tech-2 obsolete for programming so if you want to do that you'll want to go another route. Still, the Tech-2 is my go to tool for diagnostics on these trucks.

When I program modules, I hook up the battery to a tender/charger and also power the Tech-2/MDI2 with external power separate from the truck to be on the safe side.

 

[gregsmy]

It's pretty intuitive, especially if you use it with the shop manual. GM/ACDelco made the Tech-2 obsolete for programming so if you want to do that you'll want to go another route. Still, the Tech-2 is my go to tool for diagnostics on these trucks.

When I program modules, I hook up the battery to a tender/charger and also power the Tech-2/MDI2 with external power separate from the truck to be on the safe side.

So you can’t program new modules with. Tech 2 any more? Like if it needs a new display/ control module?

But you could still test and calibrate the actuators?

 

[swathdiver]

So you can’t program new modules with. Tech 2 any more? Like if it needs a new display/ control module?

But you could still test and calibrate the actuators?

That's correct, still use it for diagnostics and setting tire pressure limits, transmission adapts, calibrate actuators, etc. but not to program new modules.

 

[gregsmy]

That's correct, still use it for diagnostics and setting tire pressure limits, transmission adapts, calibrate actuators, etc. but not to program new modules.

The rabbit hole gets deeper. Since I couldnt do any programing with the TECH2 anymore I started looking at some of the similar priced diagnostic tools that have bidirectional abilities. Looks like there are a number available that can do those various tests and special functions. Since I have multiple brands of vehicles I may go this way as it would probably be a better investment for the long run.

 

[gregsmy]

That's correct, still use it for diagnostics and setting tire pressure limits, transmission adapts, calibrate actuators, etc. but not to program new modules.

After doing some research I bought the xtool D7 bi directional scan tool. Initially I did not find any codes related to the HVAC system. The scan tool allows you to do a lot of things and had the option to calibrate the system. After performing the calibration it seems to have solved my problem and everything seems to operate normally again. However after a week or so I ran the scanner on the truck to work on a different problem and I see it now has a stored trouble code for the HVAC. It lists B0423-04 "Temperature control 2 feedback circuit open". I'm not sure what that would be related to. The scan tool offers the ability for actuation, live data, graphing, etc but not sure where to start? There are also some other codes like B2470-04 "Cellular phone antenna open circuit" and U0200-00 "lost communication with door control module B".

I was going to start a new thread regarding the "service brakes soon" message I get. I have a code C0299-5A "Brake boost regulation pressure sensor plausibility failure". Not sure if any or all of these could be connected some how. I did replace the pressure sensor a few years ago for the same problem, and it went away. I have some live date of when it fails.

 

[swathdiver]

After doing some research I bought the xtool D7 bi directional scan tool. Initially I did not find any codes related to the HVAC system. The scan tool allows you to do a lot of things and had the option to calibrate the system. After performing the calibration it seems to have solved my problem and everything seems to operate normally again. However after a week or so I ran the scanner on the truck to work on a different problem and I see it now has a stored trouble code for the HVAC. It lists B0423-04 "Temperature control 2 feedback circuit open". I'm not sure what that would be related to. The scan tool offers the ability for actuation, live data, graphing, etc but not sure where to start? There are also some other codes like B2470-04 "Cellular phone antenna open circuit" and U0200-00 "lost communication with door control module B".

I was going to start a new thread regarding the "service brakes soon" message I get. I have a code C0299-5A "Brake boost regulation pressure sensor plausibility failure". Not sure if any or all of these could be connected some how. I did replace the pressure sensor a few years ago for the same problem, and it went away. I have some live date of when it fails.

Double check that the codes you are seeing are either CURRENT or HISTORICAL. Some codes clear after so many ignition cycles, others stay forever until manually cleared. There's reasoning for this but I don't remember why!

B0423 is for the passenger side temperature control actuator. Aftermarket actuators/sensors don't last or play nice with the computer system, nor do they last as long.

i would get the B2470-04 in my truck after it rained. Water would get past the antenna on the roof and drip onto the coax cable which would throw the code until it dried up later in the day. Sometimes I'd get a red light on the mirror but usually not and the phone never stopped working.

 

[gregsmy]

Double check that the codes you are seeing are either CURRENT or HISTORICAL. Some codes clear after so many ignition cycles, others stay forever until manually cleared. There's reasoning for this but I don't remember why!

B0423 is for the passenger side temperature control actuator. Aftermarket actuators/sensors don't last or play nice with the computer system, nor do they last as long.

i would get the B2470-04 in my truck after it rained. Water would get past the antenna on the roof and drip onto the coax cable which would throw the code until it dried up later in the day. Sometimes I'd get a red light on the mirror but usually not and the phone never stopped working.

I looked and couldnt find where it listed the codes as "historical". It does tell you when they where set in relation to last key cycle and if they set again after clearing. I went ahead and cleared all of them so I would have a starting point and so far they have not come back and the hvac seems to be acting normally. As far as I know it has the original actuators still in it and I will keep in mind about using original GM ones if I have a failure.

 

[swathdiver]

 

[gregsmy]

View attachment 420261View attachment 420262View attachment 420263

I do get information similar to that. I need to look at it closer to figure out how to interpret the way it displays it. Thanks