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Cooling fan issue / Enq: W210.048 - E200K - YEAR 2002 -

909 Views 36 Replies 5 Participants Last post by  NareshW210
Hi all,

I recently purchased a beautiful W210 and to my technical knowledge, it's pretty decent and everything is 100% in original condition.
However, after driving for a while now, I came to realize that while the A/C is running the cooling fan runs well at full speed and temperature stays right around 78-83dec C.
If I were to turn off the A/C and run depending on the engine temperature sensor, cooling fan only kicks in about 87degC, but the fan is not ramping up (slow speed)
as fast as it would when the A/C is turned on.
Do note my car don't have an AUX fan for A/C. Only 1 cooling fan for radiator & A/C condenser

Despite it not sitting well with me with the temperature while driving is above 80deg C, I didn't think too much about it until yesterday when I got a warning that came up.
"ENGINE FAN, VISIT WORKSHOP!"

When I rocked up at the workshop and got a diagnostic tool to run, it came up as following:
Error code# P2020-002: M4/3 (engine/AC electric suction fan), Short circuit to ground / Open circuit in wiring
*Note during this whole process my ran was running at full speed.
So, it confuses me how can it have an open circuit, or a short circuit as displayed on the error code whilst the fan is running on full speed?

The car engine was then shut off and diagnostic tool used to wipe out error code and when I started back the engine, the fault code went off and fan was running as per normal.
My mechanic is suggesting it's the fan motor; however, I am skeptical I think it may be the fan module, but I'm not sure if this model has one.


With the information above following are my question to the gurus of this forum please help me with:
1) Have anyone else encountered this?
2) Does my model have a fan module? If so what's the part number?
3) Confirm PN#A210 505 23 55 is the right part number for my car model fan deck.
4) Can i get a temperature sensor to start my low-speed fan at a lower set point, instead of 83degC maybe 70degC?

VIN#WDB2100482

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2) Does my model have a fan module? If so what's the part number?
3) Confirm PN#A210 505 23 55 is the right part number for my car model fan deck.
4) Can i get a temperature sensor to start my low-speed fan at a lower set point, instead of 83degC maybe 70degC?

VIN#WDB2100482
2. Yes it does.
3. Not without full VIN.
4. Why? There is only one temp sensor that is used for both engine management and fan activation.
 

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Discussion Starter · #3 ·
2. Yes it does.
3. Not without full VIN.
4. Why? There is only one temp sensor that is used for both engine management and fan activation.

Hi Witek_M

Thank you for your prompt reply.
My VIN#:
WDB2100482B298554


Can you please help me with:
1) Fan control module part number
2) Fan deck part number
3) Location of the dan control module

Much appreciated :)
 

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Part number for fan controller 025 545 33 32. Suction fan 210 505 23 55.

Before you buy any of those cheesy controllers read through this thread.
It starts here:

Final conclusion is here:
 

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Discussion Starter · #8 ·
Hi Wintek,

Today morning during my morning start up I noticed that when I turned on the AC the warning came up again.
When I pop the hood, I noticed the fan was not running. When temperature hits 87degC then it turns on at slow speed.

I suspect it may be the pressure sensor of the AC system that is not turning on the fan as it should.
Or it could be the control unit itself. could you please guide me through how can I check this?
Or could it be a relay if there is any?
 

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2002 S210.265 M112.941 722.618 VIN WDBJH65J02B467443
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@Witek_M
Thanks for this thread, I went from 0 to 60 in an hour regarding the W210 AC/Cooling fan system. I'm surprised it wasn't nominated for a sticky.

Before you buy any of those cheesy controllers read through this thread.
It starts here:
Final conclusion is here:
 

· W210 Section Moderator
1998 E320 base sedan @ 242 kmiles
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Hi Wintek,

Today morning during my morning start up I noticed that when I turned on the AC the warning came up again.
When I pop the hood, I noticed the fan was not running. When temperature hits 87degC then it turns on at slow speed.

I suspect it may be the pressure sensor of the AC system that is not turning on the fan as it should.
Or it could be the control unit itself. could you please guide me through how can I check this?
Or could it be a relay if there is any?
I would get the car scanned for all modules (including the climate controller, Instrument Panel, SAM, ECU).

If the fan starts spinning when the engine temp reaches 87 degrees C, then the fan controller is likely fine.

The fan will spin for the climate controller, if the refrigerant pressure sensor reading exceeds something like 17 bars, and it will spin faster as the pressure increases (with excessive idling in a hot climate, or insufficient condenser cooling / heat exchange).

It is possible that there is communications problem from the climate controller to the Instrument Panel Controller, and the ECU is not getting the refrigerant pressure sensor information.

If you press and hold the AUTO keys for 20 seconds with the engine and a/c running) the fans should spin at maximum speed. I assume you have automatic climate controller (not tempmatic).
 

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Discussion Starter · #12 ·
Hi Mr.Boca,

I have got it scanned and as i mentioned above the fault code that came up is P2020-002 M4/3.

My car is running when temperature is hot and activates but when AC is turned on its intermitter 3/10 times it fan won't run and this warning comes up.
Odometer Speedometer Gauge Trip computer Car
 

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Discussion Starter · #13 ·
Hi Mr.Boca,

My control unit is not the LCD type do note, so I can't run the fan with the AUTO button as I don't have that option.
Vehicle Motor vehicle Car Automotive design Steering part


My car is a w210.048 year 2002 E200K
VIN# WDB2100482B298554
Font Gas Metal Number Electric blue

The car comes with single fan (no aux fan for AC)
Vehicle Hood Wheel Automotive tire Motor vehicle


Here is a photo of the fan set up.

Automotive tire Bumper Automotive exterior Gas Wood


Is this where the unit senses the pressure?

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While there is no access to live data with that system from control panel there is still access with HHT-WIN but that is beyond any DIY type scanner. Autologic or DAS with HHT-WIN plugin is the only way I know. That system is common to W202.

There is still way to access fan request data from engine control module.
Here are few snapshots of fan request. It is winter here so it difficult to replicate summer conditions.
 

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· W210 Section Moderator
1998 E320 base sedan @ 242 kmiles
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Hi Mr.Boca,

My control unit is not the LCD type do note, so I can't run the fan with the AUTO button as I don't have that option.
View attachment 2803799

My car is a w210.048 year 2002 E200K
VIN# WDB2100482B298554
View attachment 2803800
The car comes with single fan (no aux fan for AC)
View attachment 2803801

Here is a photo of the fan set up.

View attachment 2803802

Is this where the unit senses the pressure?

View attachment 2803803
Hi Mr.Boca,

I have got it scanned and as i mentioned above the fault code that came up is P2020-002 M4/3.

My car is running when temperature is hot and activates but when AC is turned on its intermitter 3/10 times it fan won't run and this warning comes up.
View attachment 2803798
The question is, was the P2020 a current code, or stored code (happened in the past) ? If this code comes up again, after clearing, then it is a current code.

If the fan warning is coming up intermittently, and the above code and warning comes up when it is not fan is not running and a/c switched on. It would more likely be a wiring issue. Could be the pressure sensor, K2 wiring or the wiring to the N76 controller from the ECU (N3/4) as in the picture. It is best to check the live data on the scanner when this condition occurs.

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Discussion Starter · #16 ·
Hi guys, thanks for the information. From my diagnosis this is what I found.

compressor turns on and fan runs for a short while. When I Rev the engine the P2020 warning comes on. So to your question it was a stored error which has been cleared and came up again.

What I notice is the fault code is coming up and the fan stops when I Rev the engine, to my understanding from studying the previous thread, the fan turns on at 2v and revs up to 11v based on the pressure of the refrigerant, high pressure = higher v which turns the fan faster. But in my case it starts off say at 2v, when the engine is rev’d and pressure goes up there is a lost of contact. Because I used a test light and found no supply to fan motor during this trial
 

· W210 Section Moderator
1998 E320 base sedan @ 242 kmiles
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Hi guys, thanks for the information. From my diagnosis this is what I found.

compressor turns on and fan runs for a short while. When I Rev the engine the P2020 warning comes on. So to your question it was a stored error which has been cleared and came up again.

What I notice is the fault code is coming up and the fan stops when I Rev the engine, to my understanding from studying the previous thread, the fan turns on at 2v and revs up to 11v based on the pressure of the refrigerant, high pressure = higher v which turns the fan faster. But in my case it starts off say at 2v, when the engine is rev’d and pressure goes up there is a lost of contact. Because I used a test light and found no supply to fan motor during this trial
What happens when you turn the a/c off from the climate controller (or turn the climate controller off altogether), and rev up the engine? Do you still get P2020?

The refrigerant pressure should not go up significantly when you rev up the engine, as the compressor, while it spins faster, it will not linearly more refrigerant, as this is controlled by the expansion valve.

As mentioned before, the diagnosis is best done by looking at the live data in the ECU, checking the refrigerant pressure, fan speed, and contribution of engine coolant temperature and refrigerant pressure to the fan speed control in terms of percentages.
 

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Discussion Starter · #18 ·
So if the A/C is turned off I can drive for 2 hours with out the P2020 error coming up. This is because the fan is not given run command I guess. The temperature with the weather in Adelaide, Australia currently I can’t get the temperate to switch to call the fan to run.

so best conclusion get this to merc and get them to take a look? Or is there any more further diagnose I can do my self?
 

· W210 Section Moderator
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You can remove the connector from the engine coolant temperature sensor, and replace it with 200 ohm resistor. This would be something like 95 degrees C coolant temp, which would trigger the fan to spin faster. You can try 170 ohms which would correspond to 100 degrees C.

You need to be careful when removing the connector. It could break, if you are not careful, due to old age.

Or you could pierce the wiring to the coolant temp sensor and shunt (parallel connect) a resistor across the pierced wiring. The ECT sensor resistance is 320 ohms at 80 degrees C, so if you shunt 320 ohms across, the effective resistance will be 160 Ohms, which corresponds to just above 100 deg C.

If you have P2020 with the increased coolant temp (simulated) as the fan speed increases and stops, then the problem is NOT a/c unit related, as it should be turned off when you do this test.
 

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So if the A/C is turned off I can drive for 2 hours with out the P2020 error coming up. This is because the fan is not given run command I guess. The temperature with the weather in Adelaide, Australia currently I can’t get the temperate to switch to call the fan to run.

so best conclusion get this to merc and get them to take a look? Or is there any more further diagnose I can do my self?
Drive around then come to a stop. Fan should come on at ~96C, no AC.
That is advantage of suction fan setup. It offers very clean unobstructed air entry to condenser/radiator. Until it fails. 😷
 
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