[Witek_M]

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.

 

[NareshW210]

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

 

[NareshW210]

Hi,

From my research it is coming up with 2 part numbers for the engine cooling fan control unit.

Could someone confirm which will work?

• A 027 545 81 32
• A 025 545 33 32

Please refer to photos attached below.

Thank you

Naresh

 

[Witek_M]

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:

Engine Fan Running Too Long

Replaced engine fan with new in August (eight months ago: works fine). Replaced engine fan control module last week. Seemed to work fine. Now when car is off the fan comes one and runs constantly at high. Checked both fuses (20 and 41) and both are good. Will have to pull a fuse to keep it...

www.benzworld.org

Final conclusion is here:

Engine Fan Running Too Long

Called around town and the only one with a scanner is AutoZone: detect CEL errors, nothing more. I have an Actron OBDII scanner which says that there are NO error codes. Shocked when I looked at fleaBay: Actron 9175 scanner $225. I certainly did not pay that for it new. It did tell me once...

www.benzworld.org

 

[NareshW210]

Thanks for the heads up Witek.

Will an original part like this be a good fit rather than getting an OEM unit?

 

[Witek_M]

Yes, genuine MB is fine. Of course we don't know what's in the box.

 

[NareshW210]

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?

 

[Witek_M]

Study thread I have pointed. It has all the info.

 

[HawkRad]

@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:

Engine Fan Running Too Long

Replaced engine fan with new in August (eight months ago: works fine). Replaced engine fan control module last week. Seemed to work fine. Now when car is off the fan comes one and runs constantly at high. Checked both fuses (20 and 41) and both are good. Will have to pull a fuse to keep it...

www.benzworld.org

Final conclusion is here:

Engine Fan Running Too Long

Called around town and the only one with a scanner is AutoZone: detect CEL errors, nothing more. I have an Actron OBDII scanner which says that there are NO error codes. Shocked when I looked at fleaBay: Actron 9175 scanner $225. I certainly did not pay that for it new. It did tell me once...

www.benzworld.org

 

[mrboca]

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).

 

[NareshW210]

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.

 

[NareshW210]

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.

My car is a w210.048 year 2002 E200K
VIN# WDB2100482B298554

The car comes with single fan (no aux fan for AC)

Here is a photo of the fan set up.

Is this where the unit senses the pressure?

 

[Witek_M]

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.

 

[mrboca]

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.

 

[NareshW210]

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

 

[mrboca]

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.

 

[NareshW210]

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?

 

[mrboca]

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.

 

[Witek_M]

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. 😷