8010 A/C issues 02 code flashing

[1967806]

Saturday I got in the combine after I unhooked the corn head and cab was warm after we had been shelling corn most of the day. Number 02 was flashing in the readout with the temperature I had it set at. After awhile I started getting cool air again but not as cool as it should be. Ran it the rest of the day and sunday as well with mostly just air from the fan and numbers still flashing. Was going to clean cab filter in the cab sunday morning but didn't have a screw driver to get the cover off. Told my son if I go to the trouble of getting that cover off it will get a new filter. So Monday morning I got the cover off to replace the filter and evaporator had a little dirt in it so I brushed it off and cleaned it with shop vac. Evap. was still damp. Hooked up my A/C gauges to the lines by the compressor and had 18 in the low side and 120 on the high side. I out one can of 134 in and didn't really change the pressure much if any. After that it cooled fairly decent till about 3 o'clock and the code 02 came back. Still cooled ok though. Just wondering if the expansion valve could be bad and how to get to it and the drier? Not sure how the pressure normally look on a properly working system?   

[Powered by IH]

9 minutes ago, 1967806 said:

Saturday I got in the combine after I unhooked the corn head and cab was warm after we had been shelling corn most of the day. Number 02 was flashing in the readout with the temperature I had it set at. After awhile I started getting cool air again but not as cool as it should be. Ran it the rest of the day and sunday as well with mostly just air from the fan and numbers still flashing. Was going to clean cab filter in the cab sunday morning but didn't have a screw driver to get the cover off. Told my son if I go to the trouble of getting that cover off it will get a new filter. So Monday morning I got the cover off to replace the filter and evaporator had a little dirt in it so I brushed it off and cleaned it with shop vac. Evap. was still damp. Hooked up my A/C gauges to the lines by the compressor and had 18 in the low side and 120 on the high side. I out one can of 134 in and didn't really change the pressure much if any. After that it cooled fairly decent till about 3 o'clock and the code 02 came back. Still cooled ok though. Just wondering if the expansion valve could be bad and how to get to it and the drier? Not sure how the pressure normally look on a properly working system?   

What is your static pressures after the combine sits for a couple hours or before it's started?

Need that, the temp on the day you took the running pressure and static reading, and the approx. humidity.

[SDman]

02 error code is low pressure switch activation. 

Also keep in mind an 8010 holds 6.75 lbs of freon.

Most common places for refrigerant leakage on those is either the compressor front seal or the condenser in the radiator door leaks where the fittings are fastened to a couple brackets that like to crack and leak.

[HydroTek]

Slow leaks are common -- look for oily places on the hoses or line fittings -- look at hose end crimps and places where the lines are clamped 

if the system is just low on refrigerant , and otherwise healthy
add until you feel the rush of cold (sudden drop in temp as you are filling) in the suction line -- then about 2 oz more 
this should get high pressure in the  range -- 175 - 230

Ambient temperature makes a difference on the pressures and cleanliness of the cores 

you can get your hand on the lines where they enter the cab
small line (high pressure) should be a little warm but not hot -- if hot then see why the core is not getting air over it 
large line should be cold -- if not cold then still low on juice 

[jass1660]

Dealer just came today and changed the compressor on my guys 7120 was leaking out front seal and ran all weekend with no cold air and flashing 02 on it.

[1967806]

On 10/13/2026 at 7:38 AM, Powered by IH said:

What is your static pressures after the combine sits for a couple hours or before it's started?

Need that, the temp on the day you took the running pressure and static reading, and the approx. humidity.

I looked at that when I hooked up the gauges that morning. Dont remember what they were exactly but I remember them being just a little higher than the temperature after the combine had sat all night. 

[1967806]

On 10/13/2026 at 8:43 AM, SDman said:

02 error code is low pressure switch activation. 

Also keep in mind an 8010 holds 6.75 lbs of freon.

Most common places for refrigerant leakage on those is either the compressor front seal or the condenser in the radiator door leaks where the fittings are fastened to a couple brackets that like to crack and leak.

Condenser was replaced 3 or 4 years ago after the common problem of raccons in the fan at startup. That was a 12,000 dollar ordeal. 

[1967806]

On 10/13/2026 at 8:43 AM, SDman said:

02 error code is low pressure switch activation. 

Also keep in mind an 8010 holds 6.75 lbs of freon.

Most common places for refrigerant leakage on those is either the compressor front seal or the condenser in the radiator door leaks where the fittings are fastened to a couple brackets that like to crack and leak.

So maybe I need to add another can. It was fine today. But it was cool today and I had the temp set on 74. 

[SDman]

9 hours ago, 1967806 said:

So maybe I need to add another can. It was fine today. But it was cool today and I had the temp set on 74. 

Probably at least another can. On a late 8010 like yours, isn't the AC condenser hung on the access door to the coolers? On the opposite side of the coolers from the engine fan? I wouldn't think that one would get damaged in a "coon incident", but anything can happen. 

As far as pressures go, most Flagships I have been around run a rather low high-side pressure on their AC system until the temperature outside is north of 90 degrees...they use such a large condenser with a rather massive fan that moves a LOT of air. I put a new AC condenser/oil cooler assembly in an 8120 about a month ago....high side pressure was about 130-140psi max. It was in a 75 degree shop and the AC clutch was cycling as the cab temperature was 38-39 degrees. 

[1967806]

10 hours ago, SDman said:

Probably at least another can. On a late 8010 like yours, isn't the AC condenser hung on the access door to the coolers? On the opposite side of the coolers from the engine fan? I wouldn't think that one would get damaged in a "coon incident", but anything can happen. 

As far as pressures go, most Flagships I have been around run a rather low high-side pressure on their AC system until the temperature outside is north of 90 degrees...they use such a large condenser with a rather massive fan that moves a LOT of air. I put a new AC condenser/oil cooler assembly in an 8120 about a month ago....high side pressure was about 130-140psi max. It was in a 75 degree shop and the AC clutch was cycling as the cab temperature was 38-39 degrees. 

You might be right now that I think about it. I think its above the oil cooler that we had to change last fall. 3600 dollars and trip to a Titan dealer we normally dont deal with. Son spent alot of time washing them out this summer and we had to wash everything last fall after the oil cooler started leaking. I like the idea of low high side pressure. The line coming out of the compressor was still cool enough to hold on to. The suction line was cool enough to sweat but not as cool as monst tractors I been around. I suppose that may be the case because of the long distance between the compressor and evaporator. 

Still not sure how a person can get to the evaporator, expansion valve and not even sure where the dryer is? in the cab though if the need comes up later. 

[SDman]

Actually, the drier and the expansion valve itself are accessible outside the RH side of the cab. This picture shows the view from the area of the RH drive tires. You can see the drier; it mounts to the frame of the combine just in front of the front RH concave door. Just ahead of that is an access panel to get to the HVAC system, IIRC there should be a white sticker there that should say "ATC". Removal of that panel will show you the expansion valve....just follow the outside AC lines and they will lead you right to the expansion valve. 

As far as the evaporator, there is a screw just behind the inside cab filter you need to remove, the sensing tube for the thermostat switch, and remove the RH storage box in the cab to allow the evaporator to slide out the RH side of the cab HVAC box.

[1967806]

11 hours ago, SDman said:

and remove the RH storage box in the cab to allow the evaporator to slide out the RH side of the cab HVAC box.

What are you calling the RH storage box? The one behind the seat/console? 

 

[1967806]

On 10/16/2026 at 9:06 AM, 1967806 said:

 

I finally looked that side of the cab over the other day while I was pumping fuel in it. Was costing about 60 dollars a minute to do that. I seen that cover in that illsustration. Seems like it only acts up on warm days. Thinking I might try another can of 134 and see what happens before I dive in to that expansion valve and stuff. That whole system is something that they tried to take control of with electronics that would have been better off leaving it alone like the old days. Cant for the life of me figure out why anyone would want the blower motor to run in high speed after you first start the combine in the morning. Doesn't seem to matter where the blower speed switch is. If you move the speed switch slightly one way or the other it slows the blower down. Even moving it slightly to the high side makes it slow on ours. 

[SDman]

A few things here...

First off, your cab has 2 fans. Fan #1 is the cab pressurizer fan located behind the outside cab air filter above the LH drive tires. This fan runs at a constant speed at all times the key switch is on. It has one purpose....to keep the cab pressurized. This type of system came out on 2188s.

Fan #2 is the one that changes speed (or SHOULD change speed) with the fan speed control knob. That one works in conjunction with the HVAC/ATC system. 

As far as 02 error codes and system shutdown, one thing that is very important to maintain is the recirculation cab filter located under the RH console near the floor. That filter gets overlooked and plays a very important part in HVAC operation. Have seen many times where the filter "looks clean"; but is, in fact, rather dirty. Pop the filter out, turn on the key, and see if the air coming out of the vents is noticeably improved. If it is, that filter needs replaced. Have seen the evaporator turn into a block of ice due to the filter being plugged. 

In all honesty, the HVAC/ATC system on the old cab(6 headlights on top of the cab) Flagship combines worked very well overall. They didn't use that stupid electronic water/heater valve that was used in the Steigers/Magnums for so many years that caused so many problems. Have seen some low-pressure AC switch issues, but that usually results in a system that doesn't work right away. 

Also, when using ATC(Auto Temp Control), you need to know a couple things. First, do NOT touch the fan speed control knob when it is in ATC("A" will show on the display when it is in ATC mode). Doing so kicks it out of ATC mode, then it resorts to manual mode....like what we have always had before for HVAC control. Also, before you kick the ATC mode on, set the fan speed knob to the SLOWEST speed you want the fan to run. If you are an operator that likes a lot of fan at all times, set it somewhat higher (50% or better). If you don't want a lot of fan when the cab temp is comfortable, set it lower(25% or so). Just make sure you don't set it all the way off.

[Haystack]

Dont just slap another can in, those cans throw your readings off and you aint puttin any PAG oil back either. Best bet is pull it, vac it down, and weigh in the full 6.75 lb charge on a scale.
Before tearin into the TXV, pull a vacuum to 29 in and let it sit 30 min, if the needle creeps up you got a leak confirmed. Also check them schrader valves in the service ports, dirt cheap and a known slow leak spot. And if you open the system up, swap the drier while yer in there. Good luck 

[1967806]

On 10/21/2026 at 10:02 PM, SDman said:

A few things here...

First off, your cab has 2 fans. Fan #1 is the cab pressurizer fan located behind the outside cab air filter above the LH drive tires. This fan runs at a constant speed at all times the key switch is on. It has one purpose....to keep the cab pressurized. This type of system came out on 2188s.

Fan #2 is the one that changes speed (or SHOULD change speed) with the fan speed control knob. That one works in conjunction with the HVAC/ATC system. 

As far as 02 error codes and system shutdown, one thing that is very important to maintain is the recirculation cab filter located under the RH console near the floor. That filter gets overlooked and plays a very important part in HVAC operation. Have seen many times where the filter "looks clean"; but is, in fact, rather dirty. Pop the filter out, turn on the key, and see if the air coming out of the vents is noticeably improved. If it is, that filter needs replaced. Have seen the evaporator turn into a block of ice due to the filter being plugged. 

In all honesty, the HVAC/ATC system on the old cab(6 headlights on top of the cab) Flagship combines worked very well overall. They didn't use that stupid electronic water/heater valve that was used in the Steigers/Magnums for so many years that caused so many problems. Have seen some low-pressure AC switch issues, but that usually results in a system that doesn't work right away. 

Also, when using ATC(Auto Temp Control), you need to know a couple things. First, do NOT touch the fan speed control knob when it is in ATC("A" will show on the display when it is in ATC mode). Doing so kicks it out of ATC mode, then it resorts to manual mode....like what we have always had before for HVAC control. Also, before you kick the ATC mode on, set the fan speed knob to the SLOWEST speed you want the fan to run. If you are an operator that likes a lot of fan at all times, set it somewhat higher (50% or better). If you don't want a lot of fan when the cab temp is comfortable, set it lower(25% or so). Just make sure you don't set it all the way off.

My biggest complaint about that whole sytem is the knobs. For some reason the fan will go to full speed when you start the combine in the morning. Dont matter where the speed knob is set or what the outside temperature is. Looks to me like they way over complicated a simple comfort feature. 

[tractorholic]

Mine flashes “02” a lot . I ignore it and it works as good as it ever did. But I have to agree with 1967806, that’s a really complicated system for a solution to something that wasn’t a problem in the first place. How hard was it to have a few knobs, adjust them occasionally and go. No wonder we have so many lazy people on the planet. 

[Hudco]

i allways keep a pressure temperture chart handy

[1967806]

14 hours ago, tractorholic said:

Mine flashes “02” a lot . I ignore it and it works as good as it ever did. But I have to agree with 1967806, that’s a really complicated system for a solution to something that wasn’t a problem in the first place. How hard was it to have a few knobs, adjust them occasionally and go. No wonder we have so many lazy people on the planet. 

Just another example of people behind a desk trying to take over normal tasks to make them selves look good for the boss so they can get a raise. 

[SDman]

At the risk of playing devil's advocate....why are you guys making this so complicated? We are talking about a climate control system that consists of 2 knobs(one for fan speed control, one for temperature control) and 2 switches(one for on/off operation, one for defroster/defog operation). We also have a digital display for temperature setting and fault codes. I guess I am just curious about the "too many knobs" comments. You had more knobs on the older combines that gave you fewer features.

As far as ATC(Auto temperature Control), this time of year many customers like that feature...at least in my area. In the conditions we are in right now, there are many days that you probably need some heat in the morning, AC in the afternoon, and then heat again at night. With this system, you should never have to touch any HVAC controls from start of the morning through end of the night....other than maybe kicking on the defroster at night when the sun goes down.

As far as the fan speed going to maximum at startup, I'm not sure what to make of that. Does the digital display show a temperature value? About the only time it should be at maximum speed is if you are at maximum heat(90 degrees in the display) or maximum cool(60 degrees on the display), or if you command maximum speed with the knob. 

Now, the HVAC module is a controller that does have/need software. Maybe it needs a software update? If it does, you need a special harness that hooks up to the EST as the older HVAC modules were not a part of the main communications network of the combine itself.

In all honesty, that system worked pretty good for the time it was new....I would argue it was more reliable than the systems used by the Magnums and Steigers of that vintage. Somebody at Grand Island went with a different heater valve that what the tractors used...it was much more reliable than the valve the tractors used. The fault codes on that system allowed you to pinpoint the problem area quickly....as compared to the refrigerant pressure light we used before that made you wonder if it was a system shutdown due to the high-pressure switch being tripped or the low-pressure switch being tripped.

I suppose they could have put a thumbwheel knob in the corner of the cab for heat....just like the old 1460s did.

I would agree with the other poster's comment about evacuating the existing refrigerant in the system and filling it back up with the proper amount of refrigerant and starting from there. Neither system(old or new) works efficiently with less than the recommended amount of refrigerant in it. While this system is more electronic in control, it uses the same principles of operation as previous systems did. The 02 fault code is no different on this system than using a light on the older systems.....they both mean a pressure switch in the AC system has tripped, shutting down the AC system.

[1967806]

7 hours ago, SDman said:

 

Now, the HVAC module is a controller that does have/need software. Maybe it needs a software update? If it does, you need a special harness that hooks up to the EST as the older HVAC modules were not a part of the main communications network of the combine itself.

 

That right there my friend is one of the reasons why I made the comment about them making it to complicated. 

[HydroTek]

4 hours ago, 1967806 said:

That right there my friend is one of the reasons why I made the comment about them making it to complicated. 

yeah ...but I bet you like the auto "stuff" in your pickup truck 

the system has "rules" of operation , just like any other automatic system 
that auto temperature control system is pretty nice , since one pretty much sets the temp and forgets about messing with it as the sun changes
yeah , some of the rules are a little eccentric at first glance  

[1967806]

10 hours ago, HydroTek said:

yeah ...but I bet you like the auto "stuff" in your pickup truck 

the system has "rules" of operation , just like any other automatic system 
that auto temperature control system is pretty nice , since one pretty much sets the temp and forgets about messing with it as the sun changes
yeah , some of the rules are a little eccentric at first glance  

Nope. Have a 2011 silverado. Rubber floormat, manual window cranks, manual locks and a lever on the floor to go from 2wd to 4wd. Cruise control is about all the auto stuff I need and A/C. Dont need anti lock brakes or traction control. Dont need some stupid light coming on telling me I'm spinning and derates the throttle when you get stuck. I have no problems pulling levers and pushing buttons. I learned to drive on ice when none of the vehicles were equipped with any antilock or traction control.