w212 E350 CDI Engine Fan on High with Engine On

[Mr Greedy]

Hi all,

My 2011 E350 CDI has just started running the fan on high. It takes a few seconds for the fan to come on after engine on, and a few seconds (maybe 10?) for the fan to completely shut off after ignition (engine) off. If the key is in position II, this does not happen. This was only a short journey, and engine temperature only got to 60°C.
It is not a DPF regen, as that was successfully completed about 10 miles ago prior to the end of the previous journey and soot content is currently reported as zero.
There has been no rain for the past week here, so water ingress is unlikely to be the issue.

I've delved through iCarsoft Pro, including all live data. There are no fault codes.
The only thing I can find is that the aircon pressure is reported at 0 Bar, and I've got a new condenser and pressure sensor to fit, as I knew this was on the way out.
I'm guessing that this in turn commands the fan actuation 'on' at 90% under Electric fan for combustion and air conditioning (see screen shots from iCarsoft).

Do we think this is what's causing the issue, and replacement of the condenser and sensor and (more importantly) the re-filling of refrigerant will get rid of this issue?






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[Botus]

there's a post about running with the key out check in electrics section, suggesting to check the connection to the fan isn't corroded...

otherwise often a sign somethings wrong and as back up its running full to help out - should see something in diagnostics - ac running usually gives additional engine cooling as they have a fan to ensure sufficient air flow across the condenser, so if this is off quite likely it jacks up the engine cooling fan

 

[asg1980]

Hi all,

My 2011 E350 CDI has just started running the fan on high. It takes a few seconds for the fan to come on after engine on, and a few seconds (maybe 10?) for the fan to completely shut off after ignition (engine) off. If the key is in position II, this does not happen. This was only a short journey, and engine temperature only got to 60°C.
It is not a DPF regen, as that was successfully completed about 10 miles ago prior to the end of the previous journey and soot content is currently reported as zero.
There has been no rain for the past week here, so water ingress is unlikely to be the issue.

I've delved through iCarsoft Pro, including all live data. There are no fault codes.
The only thing I can find is that the aircon pressure is reported at 0 Bar, and I've got a new condenser and pressure sensor to fit, as I knew this was on the way out.
I'm guessing that this in turn commands the fan actuation 'on' at 90% under Electric fan for combustion and air conditioning (see screen shots from iCarsoft).

Do we think this is what's causing the issue, and replacement of the condenser and sensor and (more importantly) the re-filling of refrigerant will get rid of this issue?

View attachment 70507

View attachment 70508


Other threads I've dredged up on very similar points are:

W212 cooling fan staying on

hello everyone My e350cdi today. Fan staying on while driving. Engine temp is ok. Coolant level ok. Anyone experienced this?

forums.mercedesclub.org.uk

Radiator fan running constantly

Hi guys A couple of days ago i noticed that the radiator fan starts running immediately upon start up and is really loud the fan runs continously the first 10-15 min an then goes off. Its as if the fan is running full blast like the car thinks its overheating however the engine cannot be...

forums.mercedesclub.org.uk

Radiator cooling fan permanently running

The radiator cooling fan on my 2000 petrol C320 has just started constantly running even when the engine is cold. No messages on dashboard and I rarely have the A/C on. My MB dealer said the fan was faulty so replaced it but problem remained so original one put back. Now they say the ECU must be...

forums.mercedesclub.org.uk

Hi have the same problem with my e350cdi

Did you manage to find out what the issue was and resolve it?

Thanks in advance

 

[Mr Greedy]

Yes, a leaking/corroded air con condenser on the front of the car, resulting in no air con gas, which it appears causes this issue on these cars. Replaced the condenser, got the car regassed. Been fine since.