Problem with climate system

lincoln_zero

Dedicated LVC Member
Joined
Aug 10, 2012
Messages
923
Reaction score
76
Location
ICE COLD CANADA
So this morning took the LS to get tinted, and after leaving, I now have an issue.

AC blew cold through all vents yesterday in the 2.5 hour drive home, and all last night when I went out to dinner.

Now today here's what its doing:
Set to cold (16 degrees both sides) AC on, Circ on:
Left Driver side vent vent: Cool air (not freezing cold)
Middle two vents: Cool on top part, hot on bottom of same said vent.
Right Vent Passenger side: Very warm air.

When I raise the temps to Max heat (32): all vents blow pure hot.

2004 Lincoln LS V8.
Any help is appreciated as always fellas. Probably a common issue. But it would help to know where to start.
 
Well, unfortunately that didn't take long. While it could be something else, it sounds like low refrigerant. A check with high-side/low-side gauges will quickly confirm this or rule it out.
Is it possible the seller topped it up just before you looked at it?
Also unfortunately being in Canada complicates the problem for you. Stay away from the R-12a stuff. (I hope that's not what's in there now.)

I remember sometime in the 80s going to look at a car that was parked in an empty lot near a gas station. The seller remarked that he sure hoped it started okay since it had not been started in a month. (I had already felt the warm engine.)
Afterwards, talked to the attendant in the gas station. He said that he watched the seller go to the car 30 minutes before I got there and put a can or two of Freon in.
That said, most sellers aren't that bad.
 
Hey thanks for the quick reply.

I called the seller, he says he didn't touch the AC at all. We had a cold spell here, and when I got in the car for the first time, it was set to a warmer temp. I do think its literally just awkward timing. Tho my dad had the exact same experience you had, but with a T-Bird. Salesman warmed it up and the next day, nothing but problems on startup.
So I wouldn't rule out they may have charged it. But they deny doing so.

So i'm gonna try and have a crack at it with a friend of mine who did some mechanical work. "high-side/low-side gauges" <-- where are those? I'm not sure what I'm looking for. Thanks joegr.
 
..."high-side/low-side gauges" <-- where are those? I'm not sure what I'm looking for. Thanks joegr.

If you have to ask, you shouldn't be the one doing it...
Take it to a good AC shop or a good dealer.
 
I wouldn't be doing it alone. My friend worked as a mechanic for hyundai. Hes a novice mechanic, but knows his way around. I would never attempt anything involving pressurized lines all by my lonesome.
 
What do you recommend for freon?

It's "Suva", not "Freon". You need R-134a only (and some pag oil, of course), but you are getting ahead of yourself here.
Check the pressures. See how they fit with the factory charts to see if you are low or not. Note that Hyundai's procedures and expected pressures are different, even though they use R-134a too.
If the refrigerant level is low, you need to find and fix the leak, replace the receiver/dryer, vacuum the system out, figure out how much oil is still in there and add to get the correct amount, and then weight the correct amount of R-134a in.
 
So i haven't worked on the AC, literally after posting the weather here north of Toronto dropped to 9 Celsius.

However, I don't think I have an AC leak issue. The other day it was down to 4 degrees, I dialed down the temps to 16 Cel, the lowest it will go, and I'm getting blasting HOT air. like as if its set to MAX. I can't control my temp at all, its only pure hot.

When I turn on the AC, with my hand over the vents, I feel a slight cool air mixing in with the blasting heat. I never had this issue on my other LS's. What do you guys think it is?

EDIT: Blend door or switch be the issue?
 
...EDIT: Blend door or switch be the issue?

For the thousandth time, the LS HAS NO TEMPERATURE BLEND DOOR. Never has.

The DCCV controls temperature. These do fail. You could start with some self diagnostics.

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 DEFROST buttons simultaneously and then pressing the AUTO button within 2 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 4-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.
To exit the self-test, press the DEFROST button. This will clear all on-demand codes from the DATC module memory. If no button is pushed, DTCs will continue to be displayed.

Upon exit from the self-test the DATC module returns to operational status. The DATC module executes a hard (cold boot) reset which places the DATC system in the OFF mode.


You may get one of these codes.

B2797 2797 Driver Coolant Control Valve Open Circuit Go To Pinpoint Test J .
B2798 2798 Driver Coolant Control Valve Circuit Short to Ground Go To Pinpoint Test H .
B2799 2799 Passenger Coolant Control Valve Open Circuit Go To Pinpoint Test J .
B2800 2800 Passenger Coolant Control Valve Circuit Short to Ground Go To Pinpoint Test H .


If you don't then it could be a mechanical problem with the DCCV instead of electrical.
In that case: 2006 Lincoln LS Workshop Manual
 
WOW. ... now I know why people spend $800+ at a shop to resolve climate issues.

Ok I'll start from the beginning with a self test and scan.
 
view.php
 
Scanned car, nothing. No codes.

Called Ford, they don't have the part. Back order, and Canadian/American warehouse sold out.

The fella at CarQuest told me the part number is 604192.

Will this part work?
https://www.amazon.ca/Dorman-604-91...ls+blend+door&qid=1558472021&s=gateway&sr=8-2

If your problem is still the original one about the wrong temperature air, then NO. THIS PART WILL NOT HELP!!!
For the thousandth time, the LS does not use a blend door to control temperature, only where the air comes from and goes.

What scan tool was used? The vast majority will not pick up climate control codes. Forscan (pc version) will, Autoenginuity will, and I'm not sure what other ones. You can get the codes without a scan tool.

Front Panel DATC Module Self-Test (On-Demand Diagnostic Trouble Codes — DTCs)

On-demand DTCs are those that are reported by an ECU when a failure is detected while executing a diagnostic test. For the DATC module this means that all faults (hard) that occur while the module is conducting a self-test shall be reported as an on-demand DTC.

  • The DATC module self-test will not detect concerns associated with data link messages such as engine coolant temperature or vehicle speed signals. The diagnostic tool must be used to retrieve these concerns.
  • The vehicle interior temperature should be between 0-32°C (32-90°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false temperature sensor DTCs may be displayed.
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 DEFROST buttons simultaneously and then pressing the AUTO button within 2 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 4-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.
To exit the self-test, press the DEFROST button. This will clear all on-demand codes from the DATC module memory. If no button is pushed, DTCs will continue to be displayed.

Upon exit from the self-test the DATC module returns to operational status. The DATC module executes a hard (cold boot) reset which places the DATC system in the OFF mode.

Temperature problems are almost always the DCCV!
 
Ok thanks for all that.

So I am using an ELM 327 bluetooth mini. Probably wont give me the scans I need. But I can try anyways.

I believe you when you say its the DCCV. I am new to this so I apologize I seem green. the car is going tomorrow to my Car audio guy (who also does this type of work) and he wants to help me resolve the issue, so I will show him your post Joe. In the meantime, I will find out what scanner he has, and I will try the self diagnostic.

EDIT:
I just spent some time looking at a diagram of the LS, and now I understand. The dual climate control valve is what allows air through. I apologize joe, and thank you for the thousanth reminder lol I appreciate it.
 
Last edited:
You may get one of these codes.

B2797 2797 Driver Coolant Control Valve Open Circuit Go To Pinpoint Test J .
B2798 2798 Driver Coolant Control Valve Circuit Short to Ground Go To Pinpoint Test H .
B2799 2799 Passenger Coolant Control Valve Open Circuit Go To Pinpoint Test J .
B2800 2800 Passenger Coolant Control Valve Circuit Short to Ground Go To Pinpoint Test H .


If you don't then it could be a mechanical problem with the DCCV instead of electrical.
In that case: 2006 Lincoln LS Workshop Manual



Is it possible I might have a bad evaporator temperature sensor? I'll need the correct scanner to read out the sensor values in real time.

Will ask around for forscan or autoenginuity.
 
Last edited:
...
I just spent some time looking at a diagram of the LS, and now I understand. The dual climate control valve is what allows air through. I apologize joe, and thank you for the thousanth reminder lol I appreciate it.

No, not air, coolant. The DCCV controls the amount of coolant flowing through each heater core. Air always flows through both the AC evaporator and the heater cores.
 
Is that normal? I had some codes for the Heater valve on mine and then once I fixed that issue I ran the self-test and had the same looking stuff on my screen.
Yes, that's the last part of the test. It's so you can verify that all the elements of the display work.
 

Members online

Back
Top