2000 LS possible DVVC problem?

[roachy666]

Hey guys, been coming to this forum for help for quite awhile but this is my first post.

The problem im having is that when I run my AC the passenger side comes out cool but the driver's side comes out warm. if I close the vents on the drivers side the passenger side begins to come out warm as well. I ran the self diagnostic test, it went through the count then displayed the code shown in the image which does not appear to be on any post I have found. I checked the fuse for the dvvc valve and it is not blown. Am I right to assume the valve needs replacement or could there be some other issue? Any input is greatly appreciated, thanks in advance!

[shorod]

That's not a code being displayed, that's the display test. Looks like maybe the self test did not execute correctly.

-Rod

[roachy666]

Thanks for your reply Rod? Any idea on what could be causing this? I looked at the symptoms chart and that indicated there could be air trapped in the system. I bled the system and the problem still remains.

[shorod]

I looked at the factory service manual to see if it might hint as to why the display is doing the display test when you perform the self test. Apparently this is indicative of diagnostic codes. From the factory service manual:

The DATC module self-test through the front panel display:

• can be initiated at any time. Normal operation of the system stops when the self-test is activated.
• is entered by pressing the OFF and FLOOR buttons simultaneously and then pressing the AUTO button within two seconds. Record all DTCs displayed.
• concludes by reporting all on-demand DTCs. Follow the diagnostics procedure given under ACTION in the DTC index for each DTC given.
• reports individual on-demand DTCs as four-digit DTCs (less the alpha character).
• will calibrate all the mode doors and check all analog inputs. The DATC module will only report on-demand (hard) faults that occurred while the DATC module was conducting its self-test.
• will light all control panel display segments if no faults are detected.
• will report individual on-demand DTCs without the °C symbol lit.

Once you convince yourself that the system does not have trapped air, I'd try setting the temperature to the highest setting and see if you get good heat out of both sides. Then run it all the way cold and see if both sides get cold. If so, then it would seem the issue has to do with either the blend door feedback or the response from one or more temperature sensors.


If you have access to a professional scan tool you could monitor the reading of the various temp sensors real time to see if they are providing realistic results to the DATC.



-Rod

[roachy666]

Excellent, I will give this a shot...thanks so much for your reply

[DeltaP]

I would also start by making sure the system has a full charge of refrigerant.

[shorod]

That's a good point.

-Rod