E320 A/C warm except on freeway
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2005 E320
E320 A/C warm except on freeway
Our 2005 E320 has been having intermittent A/C cooling for awhile now. At first I thought it was cutting on and off when the car went over bumps. I checked for loose connections to the compressor-none found. The A/C rarely works when the car is idling or standing still, but usually cools fine when it is moving at higher speeds. The condenser/radiator fan is working well when the car is sitting still-lots of airflow, it roars, but no substantial cooling. The high and low side pipes are at ambient while the car is idling. I haven't checked the pressures yet, but all vents blow plenty cold when the car is moving. Any ideas?
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From: dmv
2009 E550 2000 Honda civic mash n' go
Low on freon, heat exchange switch over valve, or you may have current and stored faults for your sun sensors... I know on my 211 that was the culprit as to why mine was intermittently cold. Dang connector under hood cowling somehow got disconnected. Plugged it back in erased fault codes works fine. Do what Plutoe said first though, it's most cost effective.
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2005 E320
Update
I drove the car last night and here's what it did:
Started the car-no AC at all. High and low pressure lines same temp, warm air from vents. Headed to the grocery store and in only a few hundred feet of driving, AC starts cooling like gangbusters. It continues cooling all the way to the store, including sitting at stop lights, kept cooling after parking at the store, getting back in the car and driving home, kept cooling while idling in the garage. This does not sound like low refrigerant. I do not have gauges or much money. The wife is complaining because the AC randomly works and doesn't. This feels electrical. I have many of the diagrams on this car, but not on the HVAC system. CMRIV, where was that connector? Please help.
Started the car-no AC at all. High and low pressure lines same temp, warm air from vents. Headed to the grocery store and in only a few hundred feet of driving, AC starts cooling like gangbusters. It continues cooling all the way to the store, including sitting at stop lights, kept cooling after parking at the store, getting back in the car and driving home, kept cooling while idling in the garage. This does not sound like low refrigerant. I do not have gauges or much money. The wife is complaining because the AC randomly works and doesn't. This feels electrical. I have many of the diagrams on this car, but not on the HVAC system. CMRIV, where was that connector? Please help.
Last edited by sredwine; May 13, 2015 at 10:17 PM.
Thread Starter
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Joined: Nov 2012
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2005 E320
AC Intermittent-help!
Low on freon, heat exchange switch over valve, or you may have current and stored faults for your sun sensors... I know on my 211 that was the culprit as to why mine was intermittently cold. Dang connector under hood cowling somehow got disconnected. Plugged it back in erased fault codes works fine. Do what Plutoe said first though, it's most cost effective.
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From: dmv
2009 E550 2000 Honda civic mash n' go
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2005 E320
Update-got DTCs.
Got my friend with the factory style scanning tool to poll the car and these are the codes he pulled:
90A0 Left center vent right center vent,
9588M2/22 Center vent and flap positioning motor (mechanical fault).
I know this means a flap/vent positioning motor is at the core of the failure.
How do I get to it? My intermittent works/doesn't work bump-related symptom makes me think it's a bad connection-maybe not the motor itself. My friend said jamming the door in the AC position would work as a stopgap measure-may try this since were going to Florida next week and will not need any heat down there!
90A0 Left center vent right center vent,
9588M2/22 Center vent and flap positioning motor (mechanical fault).
I know this means a flap/vent positioning motor is at the core of the failure.
How do I get to it? My intermittent works/doesn't work bump-related symptom makes me think it's a bad connection-maybe not the motor itself. My friend said jamming the door in the AC position would work as a stopgap measure-may try this since were going to Florida next week and will not need any heat down there!
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2005 E320
Codes don't make sense(?)
The codes my friend pulled would imply that multiple motors are intermittently failing-I don't think that's likely. There must be someone that can think of a root cause of all this-that would also set those codes. Plutoe, I just subscribed to WIS-but it thinks my VIN has the comfort AAC, while the car actually has a simpler one. I can't find much out about this system-it has no level display except a round array of red LEDs for the fan speed. Is this the 580 system (comfort AAC is the 581 system).
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MB E500 4MATIC
Hi I`ve got the same problem when driving on motorway it is cooling once slow down for few minutes it`s start to blow warm. I find out that the cooling fan in engine bay when the AC is on it start spining but very slow. I`ve check with SD no fault codes when I actuate the fan via SD it`s start to blow very fast. My question is what controls the cooling fan? Thnak you in advance.
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MB E500 4MATIC
Here is yet another sad case of an individual who does not know his cars systems,plus has an excellent dagnostic tool that he does not know how to use--very sad!!
The aux fan comes on beacuse the engine coolant temp and or the refrig temp is high!
Go back and look at the AC actual values/comparisons---wada you see--if you say I don't see anything then throw the SD system in the river!! and go to a proper AC shop!!
The aux fan comes on beacuse the engine coolant temp and or the refrig temp is high!
Go back and look at the AC actual values/comparisons---wada you see--if you say I don't see anything then throw the SD system in the river!! and go to a proper AC shop!!
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2005 E320
AC warm-erratic, bumps help or hurt it.
I was thinking that the forums are to try help each other your post really doesn't help. The car was in AC shop at least 3 times since last year all of them says that there is no problem, that's why after year deside to get SD and I've got it from no more then two weeks so if you want to help fine just do it please.
Now, can anybody suggest where my problem might be? My condenser fan is screaming, but the coolant lines are the same temp (Hi press vs low press) during my failure mode. It's probably a loose/bad connection, but where? My subscription to WIS yielded a lot of info, but there was no wiring diagram for my AC system!
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From: dmv
2009 E550 2000 Honda civic mash n' go
But is your compressor clutch spinning??? Assuming you have a 112 or 113 motor. Evap temp sensor could be bad like the above said, very common problem. If it cools down on the freeway, that would lead me in the direction of your compressor being faulty at times. Higher rpm's make compressor run at a faster rate when the clutch is engaged. You could always evac and recharge, inject dye in the low side port, road test and see if anything is leaking with a proper set of goggles and or a dye light.... STAR would be your best friend right now. You could look at numerous actual values and perform multiple guided test's.
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2005 E320
But is your compressor clutch spinning??? Assuming you have a 112 or 113 motor. Evap temp sensor could be bad like the above said, very common problem. If it cools down on the freeway, that would lead me in the direction of your compressor being faulty at times. Higher rpm's make compressor run at a faster rate when the clutch is engaged. You could always evac and recharge, inject dye in the low side port, road test and see if anything is leaking with a proper set of goggles and or a dye light.... STAR would be your best friend right now. You could look at numerous actual values and perform multiple guided test's.
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MB E500 4MATIC
My engine is 113 and the compressor is without clutch. I will check again once I've got time but what I remember from last check with sd car was idling but temperature wasn't too high will check again and post here the readings. Thank you.
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2005 E320
Update-with questions
My friend got Xentry and scanned the car. The heat exchanger shutoff valve is bad-I can believe that; the temp of the air coming through the vents is hot, AC on or off. The compressor is activating-but the evaporator temp stays high- I saw 104 degrees F. I am going to replace the shutoff/ changeover valve. The main questions I have are:
Is my 580 dual zone system really equipped with a changeover valve?
Could it be the only reason my system seems incapable of cooling?
A lot of members have replaced their control valves in their compressors-should I try this also?
Is my 580 dual zone system really equipped with a changeover valve?
Could it be the only reason my system seems incapable of cooling?
A lot of members have replaced their control valves in their compressors-should I try this also?
MBWorld Fanatic!
Joined: Apr 2015
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From: dmv
2009 E550 2000 Honda civic mash n' go
My friend got Xentry and scanned the car. The heat exchanger shutoff valve is bad-I can believe that; the temp of the air coming through the vents is hot, AC on or off. The compressor is activating-but the evaporator temp stays high- I saw 104 degrees F. I am going to replace the shutoff/ changeover valve. The main questions I have are:
Is my 580 dual zone system really equipped with a changeover valve?
Could it be the only reason my system seems incapable of cooling?
A lot of members have replaced their control valves in their compressors-should I try this also?
Is my 580 dual zone system really equipped with a changeover valve?
Could it be the only reason my system seems incapable of cooling?
A lot of members have replaced their control valves in their compressors-should I try this also?
Thread Starter
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2005 E320
Update-replaced valve
OK, I replaced the changeover/shutoff valve for the heater. The DIYs on this and other forums (and Pelican Parts' excellent DIY) made it easy (but see below). The air is no longer hot coming out of the vents-success! BUT-the AC is still only intermittently blowing cold. I have not had my friend scan it yet. I drove the car to the store last night-no AC all the way there, coming back it suddenly blew cold for a few minutes. I suspect some connector is corroded/intermittent-Xentry may not find it. The heater valve connector had corroded through-one pin was stuck in the female connector in the harness, had to disassemble the plug, coax the female terminal out and extract the loose pin (whew!). Again, does anybody have a wiring diagram of the SAM that includes its connections to the sensors and the compressor? There is a Mercedes tech bulletin for the 581 system (P-B-83.30/100) that says to check connector C1 in the driver's side SAM (this might apply to 580 also?), but it has no illustrations. There is a general Xentry topic (L183.00-P-04780) about intermittent low-pressure refrigerant line failure-I may look into that further.
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2005 E320
cmriv,
the refrigerant pressures are normal-I have only been able to monitor them when the system is not cooling, but I really don't think the charge level is the problem because the car sometimes cools absolutely normally with no temp or operating time correlation-sometimes it's cold, sometimes hot, sometimes just started, sometimes it's been running for quite a while-it just randomly starts cooling! Again, does anybody have a diagram they can share of the connections between the driver's side SAM and the compressor, refrigerant pressure/temp sensor, etc? I am almost sure I have another bad connection. The diagrams and other pdfs I downloaded from WIS have lots of info, but no diagrams or photos of most of the connections in the SAM.
the refrigerant pressures are normal-I have only been able to monitor them when the system is not cooling, but I really don't think the charge level is the problem because the car sometimes cools absolutely normally with no temp or operating time correlation-sometimes it's cold, sometimes hot, sometimes just started, sometimes it's been running for quite a while-it just randomly starts cooling! Again, does anybody have a diagram they can share of the connections between the driver's side SAM and the compressor, refrigerant pressure/temp sensor, etc? I am almost sure I have another bad connection. The diagrams and other pdfs I downloaded from WIS have lots of info, but no diagrams or photos of most of the connections in the SAM.
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From: dmv
2009 E550 2000 Honda civic mash n' go
step one in climate control diagnostics, make sure system is fully charged. 210's were notorious for this. If you are 1000000000% sure your charge level is at 1.90lbs or so, then i would get star involved.... Otherwise you are just pissin in the wind. Check all your sun sensors to make sure they are plugged in as well. And you don't have any CAN faults for you climate control unit correct? Sometimes the control units take a crap as well.
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2005 E320
My friend now has DAS Star/Xentry-no CAN bus faults. The only unclearable fault that showed was the changeover valve; I have now replaced that. My system is a 580 and does not have sun sensors.
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2005 E320
AC warm most of the time
cmriv,
the refrigerant pressures are normal-I have only been able to monitor them when the system is not cooling, but I really don't think the charge level is the problem because the car sometimes cools absolutely normally with no temp or operating time correlation-sometimes it's cold, sometimes hot, sometimes just started, sometimes it's been running for quite a while-it just randomly starts cooling! Again, does anybody have a diagram they can share of the connections between the driver's side SAM and the compressor, refrigerant pressure/temp sensor, etc? I am almost sure I have another bad connection. The diagrams and other pdfs I downloaded from WIS have lots of info, but no diagrams or photos of most of the connections in the SAM.
the refrigerant pressures are normal-I have only been able to monitor them when the system is not cooling, but I really don't think the charge level is the problem because the car sometimes cools absolutely normally with no temp or operating time correlation-sometimes it's cold, sometimes hot, sometimes just started, sometimes it's been running for quite a while-it just randomly starts cooling! Again, does anybody have a diagram they can share of the connections between the driver's side SAM and the compressor, refrigerant pressure/temp sensor, etc? I am almost sure I have another bad connection. The diagrams and other pdfs I downloaded from WIS have lots of info, but no diagrams or photos of most of the connections in the SAM.
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MB E500 4MATIC
Hi all just want to share what was the problem with my A/C it is a control valve fitted on the compressor it has been changed 3 days ago and the A/C is perfect. Before that it use to cooling on freeway and blowing worm in town (when drive slowly). So hope this will help some of the forum users.
