C230 A/C Diagnostic display (Climate control)--How to use - Page 2 - PeachParts Mercedes-Benz Forum

sticksms · #16 08-03-2003, 06:34 PM

I just went out and checked again with the car running and off - 05 - evaporator temp sensor was at 101 with the car off and went down to 84 degrees with the car on and the ac running. What do you think?

Charles' method of retrieving continuous and intermittent code errors for the climate control system worked well on my 98 C280. I actually was able to delete my codes by scrolling with the auto button down to a "del" screen and hit the ^ and v buttons at the same time which deleted the codes and showed this "---" screen.

blackmercedes · #17 08-03-2003, 07:01 PM

Your evaporator temp should be about 4C, which is around 36-40F. The car has to be running for the evaporator to be cooled, and it seems your compressor is indeed cooling the evaporator.

You're going to have to go back to the dealer, for there might be two things that I can tell (Steve might have the right answer):

1. Evaporator temp sensor is off and the evaporator is not being cooled properly, and the AC is not functioning properly.

2. There is not enough refrigerant to properly cool the evaporator, and that is why the temp drop is not even close to enough. This would indicate a leak, and DO NOT recharge the system without finding the leak.

Now, if the refrigerant level falls too low, I think the system has a fail-safe mode that shuts the compressor off and saves it from being destroyed as the coolant lubricates the compressor. I woudn't put any faith in that and have the system repaired.

I re-read your posts, and it seems to me that when you picked the car up, you had NO cooling, and then you did, and now you don't. Am I right? If so, I would suspect the evap temp sensor as a coolant leak is not an on/off condition.

Is your car under Starmark?

Oh, the ACC PBU reading don't mean much when the car is off. Do them with the engine running and the AC attempting to cool.

sticksms · #18 08-03-2003, 07:34 PM

Actually I took the car to the dealership with a working AC to get sched b service and it came back not working, blowing hot air and a memory full of error codes. I pulled the codes using Charles' method, wrote them down and deleted them. I turned the car off and then back on and the AC is working ... it seems cold but it seems as though it has been cooler in the past. Is it possible that in the process of doing a schedule b maintenance the mechanic might have jarred something loose causing this to happen?

Option number 2 makes sense ... the only continuous error code was 241 which, correct me if I'm wrong may be refrigerant refill - the code didnt have any other numbers or letters in front of it as seen on the chart in Steve's article.

No my car isn't under Starmark.

I still have cool air in the car but I don't know for how long and again it seems as though it was cooler in the past.

Thanks for the RIGHT way to gather ACC PBU readings ... makes a whole lot of sense!

If you can think of anything else I would appreciate the suggestions!

blackmercedes · #19 08-03-2003, 08:14 PM

THe codes consist of the last three numbers, so 241 is indeed low coolant level. Hhhmm.

The dealer can evacuate the system and then they'll know precisely who much coolant was contained in the system. If below spec, the system has a leak. They could do a dye test.

MB systems are not designed to leak over time, so you don't periodically refill the system like domestic systems of some time back.

sticksms · #20 08-03-2003, 09:04 PM

Thanks for the info ... I think I will take it to another repair shop/dealer with a better reputation ... I took it to HBL in Tyson's corner , Va ... no one has said anything good about them in the "Good MB repair shop" forum.

Since these systems aren't designed to need refills I have to wonder about a leak occuring after something they did accidentally at the shop. They were supposed to check the coolant system for a schedule B service from what I understand ... God only knows if that happened or not. There is just too much of a coincidence - worked fine when I took it there and didn't work at all when I brought it home until I got the codes and reset it.

I wish I could do this myself ... then at least if something went wrong I would have myself to blame.

Thanks for the education ... if you have anymore ideas or thoughts on this I would appreciate hearing them!

blackmercedes · #21 08-03-2003, 09:12 PM

I don't recall a B service requiring any kind of regular check of the AC system and the coolant fill. Perhaps you are confusing it with the engine cooling system (antifreeze, radiator, etc).

It might be a coincidence, or maybe not. I would call the service writer and give them a chance to explain. They won't be able to give you a diagnosis over the phone, but might be able to explain if they did any work on the AC/ACC system.

Good luck.

sticksms · #22 08-05-2003, 09:33 PM

Hey blackmercedes (John) ... I took the car back to the dealership today ... they were not able to find anything wrong with the ac. Its cooling at 55 - 60 degrees on "LO" and they checked the ACC PBV readings to find that they were all normal -- very odd. I showed them the codes that I pulled and deleted to make the ac work again and they had no real explanation for what happened.

Oh well it seems okay for now ... now on to search this site and/or start a new thread to find information on the second problem that occurred immediately after leaving the dealer -- the check engine light came on. They pulled the codes and found that the diagnostic module reported a bad left rear O2 sensor!

Hey thanks again for the info/education ... and now back to the search page!

stevebfl · #23 08-06-2003, 07:41 AM

Unless you are having 100 degree days, 55-60 in LO blow is rather poor.

Check your evaporator temp. It should beclose to 5 deg C.

sticksms · #24 08-06-2003, 11:29 AM

Hi Steve,
The evaporator temp is listed on this post as being "04" on the climate control's diagnostics - I dont have a "04" ... it goes from "03" to "05". I assumed that evaporator temp on my car is "05" which after checking it a few minutes ago is 87 degrees F (30.5 degrees C) with the engine running a couple of minutes.

Sounds like there is still a problem ... so much for that dealerships honesty or knowledge. They supposedly hooked it up to their diagnostic devices and found "nothing" wrong with it. Back to the drawing board ... a different shop/dealership.

It is generally kind of humid in northern Va this time of year - today is no different but we haven't hit a 100 degree day yet - weve been close with 95 degree days with high humidity but that's about it - it has been a cooler than normal, very wet summer so far.

I have included the rest of the numbers spewed out by the ECC diagnostics to see if you see anything else wrong if you wouldn't mind taking a look ...

01 96 degrees F
02 85 degrees F
03 64 - 66 degrees F
05 87 degrees F
06 95
07 14.3
08 127
09 35
10 495
20 00
21 07.0
22 000
23 000
40 03
41 03
42 02
44 6-C
50 62 degrees F
51 58 degrees F
52 35 degrees F
54 OFF

Thanks Steve!

sticksms · #25 08-06-2003, 03:59 PM

My 98 C280 was fine before I took it to get routine maintenance at a dealership (FSS flight came on) ... thats what is bothering me.

I got it back with two new problems - the check engine light came on after fueling it up and the ac was blowing 100% hot air until I pulled the codes and deleted them. The air feels colder but not as cold as before ... I think I need to get a second opinion

E. Lee · #26 06-04-2004, 05:53 PM

The intermittent error codes I got from my 95 C280 are:

22, 62, 60, 80, 82

Can anyone tell me what they mean? Thanks.

E. Lee · #27 06-08-2004, 01:38 AM

Anyone please? Thanks.

stevebfl · #28 06-08-2004, 08:07 AM

OK, I looked the numbers up for you, but let use this as an example of the value of such. The info I used: the DM, diagnostic manual is available along with a sea of information for 18 dollars a day at www.startekinfo.com . Just in case you are interested you couldn't pay me 18 dollars to look this up, so if you wish to follow up these codes one must have the rest of the DM.

22 - Evap temp sensor B10/6
62 - AC comp clutch short or open
60 - AC comp clutch something else
80 - switchover valve y11/3 int fault
82 - switchover valve y11/3 short or open

Unless I had a sympton that any of the above explains I would ignore them. Except for the evap temp sensor the rest are common reoccuring codes on most any service short test. i clear cars with no complaints at service with those codes 3-4 times a week. don't get carried away. I attribute many such codes to voltage drops, mostly at starting with weak batteries.

E. Lee · #29 06-08-2004, 08:25 AM

Thanks very much.

E. Lee · #30 05-13-2005, 03:36 PM

My car shows refrigerant pressue (06) shows "Lo" and it doesn't show the pressure in bar. Does this mean that the a/c system is low in refrigerant?

Thanks in advance.