OK this is very good info.
Where do I go next.
with flap setting at 0 set to lo all flaps should be closed but both left and right side vents blow hard as well as center backset vent and console glove box.
On parts diagram I see two left and right termpering valve independent from rear console.
where do I go next.

 

on EPC flap activators are called termpering and air scoop activators but the diagnostic chart refers to diverter and blend air flap... are these the same and which are which?
thx

 

thanks for the chart. Using the test I have determined that my side flaps are never opening or closing. I assume this is vacumm controlled looking at the EPC catalog but do not know where to start determining if problem is acuator, leaking line or control module.
does anyone who what is the best starting place as the actuators look like that would be hard to get too.
Also, both side vents and the center rear console vents seem to be involved, and I assume this is not on one single vacumn line.
Help please...

 

I know this

is an old thread, but does anyone have guide how to approach access points when you determine some flaps are not working.

Bill

 

i think i may have some information that will help you. I experienced the same results as post #2 and confirmed the results with another 2001 W210 E320. I believe some of the information on Chart 2 is incorrect. I will send a follow-up post tomorrow on my results. I will also tell you what you can do to test if your actuators are working. Is that what you are looking for? I need to dig up the information and right now I'm too tired. have a good night.

 

That would be cool.
Yeah, I have a few of these flaps that don't follow the chart. I have all the drawings for the vacuum dia, but I don't know where the control manifold or the PSE I think they call it. I think I need to test the supply to the control manifold. What level of vacuum should I be at?

 

This is sure a nice chart.

Is there a spot under the hood that most of the vacuum tubes are at that you can squirt some soap water on and see the bubbles or visually see a vaccuum leak.

I am beginning to wonder with the quality of MB parts that most likely it's not a tubing issue but a bad valve? What is the general concensious of this.

Is there a picture somehow that a person can see the tubes that work the AC unit from the firewall side or is all of this under or behind the A/C control unit in the dash.

Many thanks David

 

You can test the individual actuators through the switch over valve which is located under the glove box. Use a mighty-vac. See the last diagram in post #1 of this thread:

http://www.benzworld.org/forums/w210-e-class/1718209-relationship-between-intake-manifold-pse-pump.html

good luck!

 

I know this is an old thread but I'm still hoping to get some help.

This all happened after my battery died. I got a new battery from a local dealer and after that it started. A/C control unit works fine for a minute or two after each start of an engine. By default it blows from central vents and side vents. After a minute or two central vent /flap closes and air starts blowing form the dash under the windshield and the from side vents. At this time control units to switch different vent doesn’t work. The only thing works is temp controls, auto, blower speed up/down.I have tried every possible suggestion like reset battery, reset Control unit, no faulty codes except dash board temperature sensor. I would really appreciate any suggestions. Thank you in advance

 

If your flaps don't work, you may have lost vacuum. Check the connector on the PSE pump and the t-connector (in the passenger footwell) and the connection to the switch over valve box. Also, check for the vacuum connection behind the intake manifold and the other connection points listed in the link on post #9.

If all is good there and you have vacuum all the way to the switch over valve box, do the test as mentioned in post #9 .

My car battery is under the rear seat....the same location as the PSE pump....coincidence?

My guess is that you have a ruptured/split/broken/disconnected vacuum line somewhere. If so, you would hear the PSE pump constantly running.

 

I hope some are still reading this old thread, thanks for the generous info.
After a leak in the freon-circulation, which has now been fixed by my mechanic, my flaps are not working properly. That is - they do open and close but how I would like them to.
Center vents can only distribute cold air (a/c). When I increase the heat I can hear the flaps close and I only get hot air in the left vent - the right vent stay cold.
All vents are open when I distribute cold air.
So, no heating from center and right hand side vents.
Is there any way to reset the vents through the climate control unit or is it a given that I should check the wireing, connectors and valves?
Thanks, Thomas

 

I don't understand your question. The vents open and close but not they way you want them to? When you have the a/c on, only certain vents blow cold air even though you know all the vents are open (meaning, when all vents are open some blow cold while other blow warm/hot air)? If that's the case, it's something else. I think I read something about blocked duo valves or something causing symptoms like that. You will have to dig deeper or others can provide more insight.

You can test each flap to see if they open and close. Post 9 had a link for those instructions.

I know that in my car, I can hardly get any air flow out of the left vent. Limited flow and it is not as cold as the center vents or right vent. I just live with it. Maybe you can send a video snake down the vent to see what is going on with flap? Not sure if that is possible, though.

btw, changing the temperature does not open/close any of the vents.

 

I think center vent is for cold air only.
Run full sensor readout like for AC testing and that should tell us what is going on.
Could be your duovalve is sticking.
Having 90F summer, I can only wonder where you live thohei - needing heat in the car?

 

Thank you for your answers.
I'm sorry for not being clear.

There are three vents in the car. A double vent in the middle and a vent in each side.
Until last week the air streamed in all three vents regardless if it was hot air or cold.

The EC button was stuck with its light permanently on all the time and the system could not provide cold air (a/c).
The mechanic fixed this but now the heating does work as it used to.

Now:
I can get cold air in all three vents.
But when I turn up the heat the airflow in the middle vent stops and the airflow in the right vent stays cold (maybe not a/c-cold but still much colder than the left vent).

I'm aware that things gets torn in old cars, but this is not how it was a week ago.

I did a climate unit test.
Only one error: left side: Eb1 ; right side: 416
Do you know what this means?

I tried to go through the "individual flap test" as described in post #1 since I thought this would enable me to change the settings of each flap and decide if it should be open or closed, but I don't understand how to save the settings you make.

And for Kajtek1, you're right. This is the last day of summer in northern Europe and we are enjoying a comfortable 75F, but I had to test the system after the refill of the freon for the a/c.

Thanks for all info you can provide.
Thomas

 

Thank you for your answers.
I'm sorry for not being clear.

There are three vents in the car. A double vent in the middle and a vent in each side.
Until last week the air streamed in all three vents regardless if it was hot air or cold.

The EC button was stuck with its light permanently on all the time and the system could not provide cold air (a/c).
The mechanic fixed this but now the heating does work as it used to.

Now:
I can get cold air in all three vents.
But when I turn up the heat the airflow in the middle vent stops and the airflow in the right vent stays cold (maybe not a/c-cold but still much colder than the left vent).

I'm aware that things gets torn in old cars, but this is not how it was a week ago.

I did a climate unit test.
Only one error: left side: Eb1 ; right side: 416
Do you know what this means?
CORRECTION:
I HAVE LEARNED that you should reset the reset the fault codes first. When I do this, I have no fault codes.

I tried to go through the "individual flap test" as described in post #1 since I thought this would enable me to change the settings of each flap and decide if it should be open or closed, but I don't understand how to save the settings you make.

And for Kajtek1, you're right. This is the last day of summer in northern Europe and we are enjoying a comfortable 75F, but I had to test the system after the refill of the freon for the a/c.

I'm grateful for all info you can provide.

 

What year and model is your car ? do you have dual zone a/c ?

 

W210 - E320 diesel, 2001

 

two zone a/c

 

You have a duovalve, two heater sides, and two heater sensors.

If you have right side cooler than the left side, and the both left and right zones are set to the same temperature to heat the car, you either have the duovalve sticking, or the right sensor is defective (reading higher than left, and this in turn closing the right duovalve).

What happens when you set both sides to "HI" ? does the right side also blow hot air when you do that ?

I suggest you read the sensor values and post them here together with the temperature settings at both sides. The sensor values for #3 and $4 will provide the heater temperature sensor values.

To do that:

Just set the right left temperatures to heat (like 30) to get the sensor values when heating.

 

Thank you for taking the time to answer.
The readings are:
Just after driving so the engine is 80 celcius and the left and right temperature are set to 30
1 22
2 19
3 53
4 44
5 24
6 75
7 04
8 27
9 05
10 1,7
11 3,5
12 4,1
20+21+22+23 0
24 11,5
40 74
41 33
42 08
43 136

When both sides are set to hot and full power on the fan I do eventually get semi-hot air in the right vent, but it takes longer than the left before it gets hot and the fan power is also lower than in the left vent.

 

Were these reading taken with the engine turned off ?

Also when you do the flap test, with test 2 ,"right diverter set to LO", and test 4, "right blend also set to LO", do you have airflow diverted to the right side vents from the center ?

Did the mechanic just recharge the system, or did he do anything else like change of cabin filters ?

 

The engine was off when I did the test, but warm from just running.
The mechanic only recharged the system.

I'm not quite sure what 'the flap test, with test 2' means, neither what test 4 is. Where is that described please?
Thanks

 

Sorry, I did not describe it well enough. I meant steps 2 and 4 as described in post #1 of this thread

 

I'm not quite sure what to expect from the flap test.

In step 2 the left side and the right side are equally open and air flows. There is no difference (seemingly) on the air flow weather the setting is 'hi' or 'lo'. There is no air in the center vents.

In step 4 again air flow in both right side and left side and no air flow from center vents. There is *more* airflow in the side vents when possession is 'lo' compared to when set to 'hi'.

What can be learned from these readings?

 

Hello Thomas, sorry for the delay, it was Labor Day holiday here, so, the beach time

Based on what you have done so far, I believe your right blend flap is not closing properly, as most of the airflow that comes from the evaporator is bypassing the heater core due to the right blend door being fully open. So you get the cool(er) air than the left side (which seems to work properly). The heat will not come from the center vents by design, but the cooled air should come from both center and side vents. In the cooled air case, the right blend flap being open will not make any difference because the right heater core is cool, due to duo valve being closed to prevent hot coolant to circulate in it.

That is my theory anyway.. What can cause this assuming that the a/c mechanic did not touch any internal vacuum valves / controls / hoses ? It could be a vacuum leak problem which the mechanic may have knocked of, f or overbend one of the vacuum hoses to the a/c system in the engine compartment accidentally.

If this problem did not exist prior to a/c service, and exists now, I would take it to the mechanic and tell him about the situation. He should be able to diagnose this problem much better. Recharging the system with refrigerant itself will not likely to cause the problem you are having.

 

Hello MrBoca, Thank you for the reply and happy Labor Day!

Thank you very much for the diagnosis!
I am sure this analysis will help my mechanic solve the problem faster. If anything enlightening comes out my next work shop visit I will post it here.
Again thanks!