XC90 a/c right cold, left warm PHEW it's hot in here!!

[precopster]

Hi there folks. Just wondering if any of you has some insight into the workings of XC90 a/c.

A friend of mine asked me to read his '06 XC90 2.5 litre diesel today with Vida as his climate control or A/C wasn't working as it should.

After startup the A/C blows cold from the driver's vent and warm for the passenger vent. After viewing the a/c compressor cycle through Vida it seems the compressor stays on for over 3 minutes and didn't cycle ON/OFF at all. I also couldn't hear it clicking.

I tried a recalibration of the ECC through Vida. It asked me to connect VCT 2000 and then returned to a screen in Activations again. I don't know if it calibrated at all.

It still blew warm through the pasenger vent. My feeling is a flap motor or solenoid has failed but I didn't know which item to test in Vida. There's an attached readout from Vida. I don't know if the ECC code below is related. I cleared the ECC code.

He also occasionally gets an Anti-Skid warning. I assume he needs a new steering angle sensor?? (the system indicated this would be a symptom)

Any experience with this system would be greatly appreciated.

[jimmy57]

add 1/2 pound refrigerant and see if the condition is fixed. Evaporator will not be cold all the way across when refrigerant is low. The a/c temp probe in on left side of case and will not be seeing the temp drop low enough to case CCM to cycle compressor.
To check door positions go to Vehicle Communication and select the Advanced tab (I think it is Advanced, I am not near VIDA to look) and the desired and actual positions for doors are shown. A door problem would show there, especially if you move the temp knobs to max cold temp to force end stop position of the temp control doors if they are not already there.

The connection from SAS onto SWM needs to be checked/cleaned inside the column cover behind wheel. The 000E means the SAS is missing the initial waking commands/roll call on the network.
No BCM codes is unusual.

[JDS60R]

I once has a seat heater temp module under seat short out in my 07 and cause this.

[jimmy57]

Yes, the seat heater modules are on the LIN BUS's for the right and left sides respectively and they take down the LIN communication and don't necessarily gives codes. If the SHM is it then the temp will not go hot and back to cool/cold if you turn temp knob for that side to full hot and then wait to see if it blows warm on that side and then back to full cold to see if it cools again.

[precopster]

In this case the temp control allowed the temp to increase on both sides when placed up to max. position. The main problem was that the passenger side was a lot warmer than the driver's side. My guess was around 3-4 degrees celsius difference.

So in this case I guess it's back to the a/c refrigerant as even the driver's side wasn't anywhere near as cold as expected.

Will see if my friend wants to take this to an a/c specialist as we can't buy refrigerant here in cans any more due to requiring a refrigeration mechanic's license. Perhaps he will have the SAS looked at while he's there.

[ggleavitt]

Have a post on another Volvo site relating to no cool air on the driver side while the passenger side works just fine, with a corresponding CCM-DD01 (LIN bus1) code. Came up out of the blue in the '08 a few weeks ago, with all the other symptoms matching.

Seat Heater Module (SHM) got replaced. Pretty sure PNs 31268907,30710791, 30762217, 30774204 and 30795503 will all work, I used a 30774204 and now everything is back to functioning properly.

Was a pretty easy issue to resolve in the end. If the error was LIN2 it would have corresponded to the passenger side.

As always, might not be your problem (especially if your car does not have heated seats) but there's not a lot that's published on this specific scenario so thought to tag onto this post and pass on.