2009 Tahoe AC problem !!!

[Ejbarah]

Hi everyone

2009 Tahoe with Manuel Control (CJ3)
I had no problems with AC and it was blow really cold air but
After ECU software update throw ACDelco SPS website had this problem.

AC compressor engaging and after minutes disengaging for seconds and then come back again.

I replaced the Ambient Air Temperature Sensor, compressor pressure switch, compressor sensor, A/C refrigerant is good. But with no luck still same problem.

TECH2 there is no DTCs at all but :

OUTSIDE AIR TEMP RAW 1 °C and the real temp is 45 °C in my country.



I checked another car but with auto climate control to see the TEMP :
its show the actual Temp.

 

[swathdiver]

Is that the air temperature sensor behind the grill? Is it possibly blocked or connected wrong or even though new it could be bad. @Doubeleive

 

[Doubeleive]

Hi everyone

2009 Tahoe with Manuel Control (CJ3)
I had no problems with AC and it was blow really cold air but
After ECU software update throw ACDelco SPS website had this problem.

AC compressor engaging and after minutes disengaging for seconds and then come back again.

I replaced the Ambient Air Temperature Sensor, compressor pressure switch, compressor sensor, A/C refrigerant is good. But with no luck still same problem.

TECH2 there is no DTCs at all but :

OUTSIDE AIR TEMP RAW 1 °C and the real temp is 45 °C in my country.

View attachment 202902

I checked another car but with auto climate control to see the TEMP :
its show the actual Temp.

View attachment 202903

I was told that the sensors have to recalibrate, try driving it 5-6 miles and see if the sensors go back to normal

 

[Doubeleive]

Is that the air temperature sensor behind the grill? Is it possibly blocked or connected wrong or even though new it could be bad. @Doubeleive

I think the sensors have to recalibrate whenever you mess with the a/c controls which would probably include flashing them by driving it 5-6 miles, when I replaced my control unit the temp was froze on the wrong temp, dealer told me to drive 5-6 miles and see if it recalibrates, sure enough as soon as I got about 4 miles down the road it started moving towards the correct temp and went back to normal operation. I am ordering my tech2 today on a side note, lol

 

[Ejbarah]

@swathdiver yes the sensor behind the grill its clean and not block.
@Doubeleive I already re-calibrate the sensor its show actual TEMP on cluster but not in tech2.
I even re-calibrate and reset climate Temp control, re-calibrate all actuators.

By the way my Tahoe come with only one temperature sensor behind the grill. Not like the Auto temp control model comes with more than 1 sensors.
so mine is basic 1 sensor 1 pressure sensor 1 low pressure switch.

 

[Doubeleive]

strange, what was the original problem?

 

[Ejbarah]

@Doubeleive

Before There is no problem with HVAC at all . But after i update ECU and BCM software from GM online website.
the HVAC act like crazy sometime blow cold sometime warm air.

I update the ECU and BCM once again successfully but still no luck.

I update the Climate temp control from GM online too but nothing changed.

Now the AC work but like i said sometime cold and then warm air because the compressor is off for seconds.

When i go for a drive i see the RPM gauge move when AC turn off and back again alive.

That is why i checked HVAC with tech2 to see if there is problem and there is no DTCs at all.

 

[swathdiver]

Check the information used to update your BCM. If you selected auto HVAC and not manual or a different part number than what corresponds with your VIN it could wreak havoc throughout the system. There's also the possibility that the new part is simply no good.

Glad you were able to get connected with Tis2Web.

 

[Doubeleive]

I would say like james says above, double check that the update is correct, if so then maybe the update is just not working like it should, is there a option to roll it back to previous version?

 

[Ejbarah]

@swathdiver
The BCM information is correct and the manual HVAC is selected with correct part number.

Finaly i get access to TIS2WEB thanks man.

@Doubeleive
The update is correct and i do it 2 times. If you update You cannot roll back to previous version.