New Owner Questions (DATC)

[agrothudm]

Hello All,
I have spent the better part of a month stalking your forum before i purchased a used 2002 Lincoln LS V8. Thanks to the knowledge on here i was able to beat the guy down selling the car. The issue I have questions about is with the DATC (I believe). When i first ran the diagnostics it threw codes 1253, 1257, 1261, 1967, 2429, 1947 and 1676. I reset the codes and ran it again with no error codes coming up now. The only issue is i don't have any heat. The only other oddity I see is that when you hit the "auto" button it always defaults to A/C even if the temperature is set at 90*. The other LS forums i visit immediately call for you to replace the DCCV but i am not convinced this is the issue. Out of the codes that were present initially I noticed the "battery volatage out of range" and so i bought a new battery but still nothing. Also topped off the coolant and bled the system. There are no leaks in the system (shockingly) and it bled way easier than i thought after reading how this can be a tough process.

I would love to hear any of your thoughts. Possibly aux pump?

I post this as i am in the middle of doing the coils, plugs and VCG so i could use a distraction with some answers.

Thanks for any help!

 

[don-ohio]

Well,if you're NOT replacing all the plastic cooling parts,you'd be wise to make sure you have a 60% antifreeze to 40% water mix in there and then loosen the degas cap to prevent a costly repair in the near future. If you want to have to replace all those parts,of course you can do so. Tryin'to save you money here and `down time'. don-ohio ^)

 

[agrothudm]

Thanks for the reply Don. I noticed this in one of the other threads that you suggested 60/40 antifreeze to water. May i ask why that precise mix? Also any thoughts on why no heat?

 

[don-ohio]

It's not precise,just don't go less. You can go up o 70% ,but not above. Make sure your antifreeze tests at 45 below zero at ambient temp,like your coolant you're testing is about 70 degrees and you're fine.
By doing this,you'll not be blowing plastic parts,(Degas bottles178 bucks each for the good ones),and hoses. don-ohio ^)

 

[RigsLS]

Careful, next he's going to suggest you put 5W30 in the engine instead of the Manufactures' recommended grade.


Aux coolant flow pump on the 1st GEN LS'es is only faulty when it does NOT produce heat at idle but DOES at highway speeds. (higher RPM's)

If that's not the symptoms then that's not the problem.



The solenoids inside the DCCV go bad over time. There are several troubleshooting methods to determine it's faults or not. Check fuse #1 underhood.
Generally the DCCV needs replacing when you get full heat out of one side but not the other. Common symptom is with A/C ON, full heat out of passenger side. (stuck on)


The DATC has also proven over time to be a troublesome piece. A scrap yard replacement is an option.



some links to aid you in your troubles;

http://deneau.info/ls/s6x~us~en~file=s6xc0003.htm~gen~ref.htm#extract_246


GEN I - Understanding Climate Control System - No Heat Information

Dccv?


NOT your problem >> Re&Re - OEM Auxiliary Coolant Flow Pump - GEN 1 V8

 

[don-ohio]

Above is all good advice.....but you can use whatever grade you prefer. I only stated what I use and every purist here took offense to it. LOL! don-ohio ^)

 

[LS4me]

...The only other oddity I see is that when you hit the "auto" button it always defaults to A/C even if the temperature is set at 90*.....

That's perfectly normal. Get an owners manual and it will explain why.

 

[agrothudm]

Appreciate the input. There is definitely no change in temperature from one side of the car to the other so i am guess the aux pump isn't the problem either. I am thinking more and more that the DATC might be the issue since it is telling the system to run A/C on "Auto" even when i am asking for 90* temps. I just checked local junk yards and there is one nearby with 5 gen I Ls's. Hopefully i can get lucky and teach myself how to remove the DATC on their cars so I won't damage mine.

BUT I am OCD so i had to go run and test the last things on this list i haven't checked. Inlet hoses to the heater core - Cold. Inlet hoses (the only two i could physically touch) - Cold. According to the link from Deneau I have a thermostat problem. That still doesn't explain why the A/C is always selected when i hit the "Auto"feature but maybe it is both issues.

 

[LS4me]

Appreciate the input. There is definitely no change in temperature from one side of the car to the other so i am guess the aux pump isn't the problem either. I am thinking more and more that the DATC might be the issue since it is telling the system to run A/C on "Auto" even when i am asking for 90* temps. I just checked local junk yards and there is one nearby with 5 gen I Ls's. Hopefully i can get lucky and teach myself how to remove the DATC on their cars so I won't damage mine.

BUT I am OCD so i had to go run and test the last things on this list i haven't checked. Inlet hoses to the heater core - Cold. Inlet hoses (the only two i could physically touch) - Cold. According to the link from Deneau I have a thermostat problem. That still doesn't explain why the A/C is always selected when i hit the "Auto"feature but maybe it is both issues.

Again.... NORMAL!! The climate control system does more than remove heat (cool). It also dries the air to prevent inside condensation. Get an OM (or search for one) and read up.

 

[agrothudm]

I apologize as I do not see this in the owners manual. It mentions that A/C will operate as long as the outside temperature is over 35* but makes no mention of why the A/C would automatically be selected even at "heating" temperatures. Maybe it is mentioned in a different manual from my 2002 manual. I would appreciate any insight. Thanks

 

[LS4me]

I apologize as I do not see this in the owners manual. It mentions that A/C will operate as long as the outside temperature is over 35* but makes no mention of why the A/C would automatically be selected even at "heating" temperatures. Maybe it is mentioned in a different manual from my 2002 manual. I would appreciate any insight. Thanks

I had a 2000 and this is page 36...

In defrost or floor/defrost mode, if the temperature is about 2°C (35°F) or higher, the air conditioner will automatically dehumidify the air to
reduce fogging. However, the A/C indicator will be off and the A/C
override control cannot be selected.
When AUTO is selected, the A/C operates automatically for existing
conditions. You may override the A/C at any time. To manually control
the A/C, press the A/C control to cancel the A/C automatic operation.

 

[agrothudm]

Thanks I actually just found it as well. Page 51 of my manual. it was a left over paragraph from the page before and i was trying my best to speed read. Thanks for the clarification. I appreciate it. Now to change out the Thermostat and see if that helps.

 

[don-ohio]

Saw a post where the parts were really dirty inside on the auxiliary pump and maybe DCCV and hadda be cleaned out. When you do the thermostat(I would only buy Ford) you might want to make sure sludge and dirt hasn't stopped up those parts. Does your temperature gauge read low?
Also the heater radiator could be plugged up. don-ohio ^)

 

[oddball]

I have an '02 V8 and have done way too much work with the DATC, cooling system and A/C.

As stated, the DATC engaging the A/C when in "Auto" is NORMAL. Even when calling for full heat. Some of the late '02 DATCs simply don't illuminate the A/C light when you choose auto!

Did you run the bleeding procedure - to the letter? Do not use the Denau one, that's for '06 and the Gen 1 V8 is quite a bit different for the front cooling parts. The Gen1 procedure has been posted here, but I would STRONGLY recommend getting a set of 2002 service manuals - there's two volumes plus a wiring manual. Follow the procedure PRECISELY.

The Aux pump is responsible for providing heater core flow at IDLE ONLY. That's why the bleed procedure says to check for heat at 2000RPM, then let idle and make sure there's still heat.

If all the heater core hoses are cold, then here would be my priority list:
1) Ensure the heater core is properly bled
2) Verify DCCV functions correctly
3) Verify DATC functions


#1 - see the service manual

#2 - there's a check procedure for this to verify the solenoid resistance. However, it's quite common for these to stick open or shut. It's more common to stick open, but I've had them stick shut.

#3 - this is unusual, but there's a procedure in the service manual to verify the signals coming from the DATC. My DATC stopped signalling the driver side of the DCCV correctly.


If you must swap the DATC, you can use any Gen 1 DATC even though each year uses a different part number - they all interchange. However, I've pulled two bad ones from the junkard. If you're really stuck, I have a spare tested '02 DATC on the shelf.
There's nothing terribly surprising in the procedure to R&R the DATC, at least. Look for directions on how to R&R the radio - the DATC is in the same bracket.
My last go at the DCCV took about 1.5 hours, working mostly from the top. Most of the procedure from the service manual worked OK, but you might have to get creative on removing the DCCV from its mount. Well, I removed the fan hydraulic pump so I have quite a bit more room down there. Extensions and universal joints are your friends. And someone with small hands.

I also have a used DCCV on the shelf. I need to do a closer inspection, but it should be in good shape.

 

[agrothudm]

Saw a post where the parts were really dirty inside on the auxiliary pump and maybe DCCV and hadda be cleaned out. When you do the thermostat(I would only buy Ford) you might want to make sure sludge and dirt hasn't stopped up those parts. Does your temperature gauge read low?
Also the heater radiator could be plugged up. don-ohio ^)

The car gets right up to mid temperature after about 5 minutes of driving then doesn't fluctuate much from there. I am going to flush the heater core tomorrow to make sure there is flow. Haven't had a spare moment to try the new thermostat yet. And yes, I bought the Ford part.

 

[agrothudm]

Thanks Oddball. Once i flush the heater core i will run through the solenoid check to make sure everything is working properly there too!

 

[joegr]

Thanks Oddball. Once i flush the heater core i will run through the solenoid check to make sure everything is working properly there too!

Everybody always wants to blame the heater cores (there are two of them) first, but so far it never has been them (they are not the most restrictive part). If it is a clog, it is in the screen in the upper radiator hose, the DCCV, the aux pump, or someone put plugs in the heater hoses (instead of replacing a failed DCCV). The most common cause of a no heat condition is that there is air trapped in the heater coolant loop.

 

[RigsLS]

^

... Also topped off the coolant and bled the system ...

I'd bother recommending that the entire plastic cooling system be inspected and replaced but I've given up hope with this latest craze of leaving the degas bottle cap loose resolves all.

 

[oddball]

There is one fascinating story where someone found the common line to the heater core (there's three lines - one for passenger side, one for driver, and a common. I just can't remember which is input and which is output) plugged with a wooden dowel.

Thankfully the quick disconnects on the three lines are relatively easy to get to. I work on those very slowly and very gently. It's finicky to get the tabs unhooked, but it's also 14+ year old fragile plastic like everything else under the hood. Once off, it'd be easy to connect some large hose (5/8" or 3/4" I think) to flush it out.