Just in time for summer the D90 A/C started acting out yesterday (last week it was the D5 that presented and A/C issue that was solved by a refrigerant recharge with dye to check for small leaks as it passed the pressure test).

The driver aide seems to be blowing cold air but passenger side not as much. I used the GAP tool to check for codes and do some diagnostics and this one leads me to think that my issue is a faulty actuator or stuck blender door. If I am reading this correct, the system is asking for the motor to have the cold air bypass flap at 100% but the actual flap is at 0% (I also checked with GAP’s live value the other actuators and the Evaporator temperature and it all seems to be as it should). To confirm my hypotheses I then turned on the heater (i.e. set the driver and passenger temps at max temp) and the requested position value went to 0% while the measured staid at 0%. So either the flap is stuck and the actuator can’t move it or the motor is faulty. Anyone here has had an issue with that motor? I checked the workshop manual and it’s actually not too hard to get to it so I’ll probably do that, but figured I check here first to see if this has happened to anyone else.

EDIT: I might have been too quick at saying it’s not too hard to get to it. Have to pull apart half of the dash… 🙂. Before I go down that rabbit hole does anyone know the procedure to reset all actuators?

 

Have you checked if the sync option is selected? Also try selecting max a/c after making sure the sync option is selected, maybe that will make the actuators position themselves as they should.

 

I used the GAP tool to reset the actuators (Service/Test >>> HVAC Module >>> Actuators end stop detection) but that did not help. Did another round of Live Value monitoring for all actuators including the air recycling flap while playing with the HVAC controls (full LOW to full HI in SYNC and non SYNC mode) and all of them are working as they should (i.e. requested and measured values are consistent) with the exception of this one, so seems like I will have to go down the path of replacing it. I did see there was a newer ECU file for the HVAC module (once again using the all-powerful GAP IID tool, in this case the ECU Info functionality), so as a hail Mary I might reflash the ECU to see if it miraculously fixes it (I am skeptical though). I have been looking more closely at the disassembly required to get to the actuator and it looks less daunting now (though still probably a full weekend day's worth at my calm speed). Will report back.

This is one of those things where the culprit part is a couple hundred bucks, but the labor involved is probably in the thousands plus the most likely post fix frustration when all sorts of things start manifest themselves related to the work (I still have to get rid of some nooks and crannies from when the local dealer removed the back interior panels to replace a speaker). So another LR sponsored weekend distraction for me!