'02 LS with occasional A/C problem

[vellis]

Hi,

I'm new to the forum and a 7 month LS owner ('02 V8 with 55Kmiles). Im having a problem with my A/C, and it appears to be a known issue with the LS (TSB Article No. 03-3-4 ) discussed in thread Http://www.lincolnvscadillac.com/showthread.php?t=8392.

My question - Can anyone help clue me in on how I can isolate the issue to the DCCV or DATC?


Symptoms - Driver side A/C will cool down, then switch to blowing hot air. Passenger side continues to cool.

What I've noted -
Seems to only occur when temperature >90, but not sure
Seems to occur only when interior temperature reaches driver set point (ie 72oF).
Seems to work again if I shut car off for a couple of minutes, causing temperature to fall below set point.
Sometimes works again if I send interior temperature to 90oF and back to 65oF.
If I set cooling to 65oF, it will continue to blow cold air and not have problem.

I'd appreciate any assistance/advice.

Thanks,
Vince

 

[vellis]

Hi,

I'm new to the forum and a 7 month LS owner ('02 V8 with 55Kmiles). Im having a problem with my A/C, and it appears to be a known issue with the LS (TSB Article No. 03-3-4 ) discussed in thread Http://www.lincolnvscadillac.com/showthread.php?t=8392.

My question - Can anyone help clue me in on how I can isolate the issue to the DCCV or DATC?


Symptoms - Driver side A/C will cool down, then switch to blowing hot air. Passenger side continues to cool.

What I've noted -
Seems to only occur when temperature >90, but not sure
Seems to occur only when interior temperature reaches driver set point (ie 72oF).
Seems to work again if I shut car off for a couple of minutes, causing temperature to fall below set point.
Sometimes works again if I send interior temperature to 90oF and back to 65oF.
If I set cooling to 65oF, it will continue to blow cold air and not have problem.

I'd appreciate any assistance/advice.

Thanks,
Vince

OK, How about this hypothesis -

I can manually work everything correctly (air, heat, etc).
The unit only fails when it starts to throttle back on cooling after reaching set point.
The failure doesn't "go away" when the car heats up over set point (it only starts working again when manual adjustments are made - restart car, cycle temperature settings).

These things make me thing it is the DATC and not the valve. Any comments?

thanks :feedback

 

[SilverLS]

OK i was talking to my friend who is a car god!! im serious he knows it all cuz mine did this one day He told me that there is a "door " that seperates the incoming cold air from the incoming hot air and sometimes it malfunctions and that is what will happen i cant remember what its called but might help??

 

[vellis]

OK i was talking to my friend who is a car god!! im serious he knows it all cuz mine did this one day He told me that there is a "door " that seperates the incoming cold air from the incoming hot air and sometimes it malfunctions and that is what will happen i cant remember what its called but might help??

SilverLS - Thanks for the response. The way I believe things work is

Airflow is directed either over the heater core (in heat mode) or bypasses the core in A/C mode. I think there is a water valve that allows engine coolant to be directed through the heater core when in heat mode, or restricted in when in A/C mode. I've ordered the DVD manual (hopefully that will clarify the situation).

I tend to agree with your friend that my incoming airflow is being miss routed.

If the air (or water) is not working correctly, the next question is "is it the controller or the controllee"? I'm leaning to the contoller since all other functions (manual control, etc) seem to operate correctly.

 

[eL eS]

There were some folks that this problem a long long time ago when I attened the llsoc forums and it was not the controller rather they had to dismantle the dash and a bunch of other BS.

I would try posting this on www.flateratetech.com as well. Lots of tech over there and they are all FLM guys.