HELP! 01 C240 cooling Fan problem.
08-30-2009, 07:33 PM
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2001 c240
HELP! 01 C240 cooling Fan problem.
Hi All,
I'm new to this board, I recently purchased a 2001 C240. In the past few weeks, the AC wouldn't blow cold air unless I'm on the freeway. I took it to the local Mercedes repair shop here in Vegas, and they determined that the temp sensor was bad(it was reading lower than actual engine temp) so the fan would kick in late.
In turn, one of the wires inside the fan control module got fried for some reason and that was replaced, along with the temp sensor. The mechanic started the car, turned the AC on, and viola! The fan turned on right away on the high mode. Unfortunately, After about 20 minutes of it running perfectly, the fan just died. He let the car cool down, and same thing happened again.
He checked everything again, and everything checked out, fan works as it should when jumped, temp sensor is good, but There seems to be very little voltage coming from the ECM from what he told me.
Has anyone dealt with this issue before? Anyone who can point me in the right direction? I really need help. The car's been in the shop for over a week, and I am just really getting frustrated with this car. Thanks in advance for your help!
BTW, I tried using the search feature with no answers.
Regards,
JT
I'm new to this board, I recently purchased a 2001 C240. In the past few weeks, the AC wouldn't blow cold air unless I'm on the freeway. I took it to the local Mercedes repair shop here in Vegas, and they determined that the temp sensor was bad(it was reading lower than actual engine temp) so the fan would kick in late.
In turn, one of the wires inside the fan control module got fried for some reason and that was replaced, along with the temp sensor. The mechanic started the car, turned the AC on, and viola! The fan turned on right away on the high mode. Unfortunately, After about 20 minutes of it running perfectly, the fan just died. He let the car cool down, and same thing happened again.
He checked everything again, and everything checked out, fan works as it should when jumped, temp sensor is good, but There seems to be very little voltage coming from the ECM from what he told me.
Has anyone dealt with this issue before? Anyone who can point me in the right direction? I really need help. The car's been in the shop for over a week, and I am just really getting frustrated with this car. Thanks in advance for your help!
BTW, I tried using the search feature with no answers.
Regards,
JT
09-01-2009, 07:37 AM
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Before doing any aircon diagnosis you have to ensure that you have the correct refrigerant pressure in the system. I have posted the MB manual comments in this regard numerous times translated from German. There is a pressure switch in the system to protect the compressor. If the pressure is below spec it shuts everything down apart from the interior blower fan. Have your 134a pressure checked and topped up as necessary.
09-02-2009, 03:01 PM
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2001 c240
Thanks for the reply! The refrigerant is filled to spec, and when tested, it was running fine with the fan @ full speed when a/c is turned on and keeps running for about 20 minutes. After that, the fan just shuts off by itself.
When jumped, the fan runs fine, but there is barely any voltage going to it after running for a while.
Would it be worth it to get a used ECM from another C240? Or is the stock one something that can be reprogrammed for cheap?
When jumped, the fan runs fine, but there is barely any voltage going to it after running for a while.
Would it be worth it to get a used ECM from another C240? Or is the stock one something that can be reprogrammed for cheap?
07-31-2013, 11:11 PM
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This could be an ecu related problem
If you have to replace the ecu here are some pretty good instructions on how to remove and install a new c240 ecu. If you guys need any help along the way send me a message. http://www.mercedesecm.com/remove-ecu.html The trick to removing the control unit is to close the hood so that the wipers go to the up position. The hood has to be shut in order to get the wipers out of the way. Its fairly simple to remove.
08-18-2018, 11:53 AM
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Mercedes Benz c240 2002
Hi All,
I'm new to this board, I recently purchased a 2001 C240. In the past few weeks, the AC wouldn't blow cold air unless I'm on the freeway. I took it to the local Mercedes repair shop here in Vegas, and they determined that the temp sensor was bad(it was reading lower than actual engine temp) so the fan would kick in late.
In turn, one of the wires inside the fan control module got fried for some reason and that was replaced, along with the temp sensor. The mechanic started the car, turned the AC on, and viola! The fan turned on right away on the high mode. Unfortunately, After about 20 minutes of it running perfectly, the fan just died. He let the car cool down, and same thing happened again.
He checked everything again, and everything checked out, fan works as it should when jumped, temp sensor is good, but There seems to be very little voltage coming from the ECM from what he told me.
Has anyone dealt with this issue before? Anyone who can point me in the right direction? I really need help. The car's been in the shop for over a week, and I am just really getting frustrated with this car. Thanks in advance for your help!
BTW, I tried using the search feature with no answers.
Regards,
JT
I'm new to this board, I recently purchased a 2001 C240. In the past few weeks, the AC wouldn't blow cold air unless I'm on the freeway. I took it to the local Mercedes repair shop here in Vegas, and they determined that the temp sensor was bad(it was reading lower than actual engine temp) so the fan would kick in late.
In turn, one of the wires inside the fan control module got fried for some reason and that was replaced, along with the temp sensor. The mechanic started the car, turned the AC on, and viola! The fan turned on right away on the high mode. Unfortunately, After about 20 minutes of it running perfectly, the fan just died. He let the car cool down, and same thing happened again.
He checked everything again, and everything checked out, fan works as it should when jumped, temp sensor is good, but There seems to be very little voltage coming from the ECM from what he told me.
Has anyone dealt with this issue before? Anyone who can point me in the right direction? I really need help. The car's been in the shop for over a week, and I am just really getting frustrated with this car. Thanks in advance for your help!
BTW, I tried using the search feature with no answers.
Regards,
JT
Hello , I have a similar problem. My A/C is only cooling when I’m driving, but if I get to an stop light it only blows warm air .. I notice that my fan does not kick in at high speed it only does at a steady low speed. My engine does not heat up.. I will like to know how can I trouble shoot this so I can get to the bottom of this before taking it to a mechanic any help would be appreciated .
Regards
08-20-2018, 05:33 PM
#6
Hello , I have a similar problem. My A/C is only cooling when I’m driving, but if I get to an stop light it only blows warm air .. I notice that my fan does not kick in at high speed it only does at a steady low speed. My engine does not heat up.. I will like to know how can I trouble shoot this so I can get to the bottom of this before taking it to a mechanic any help would be appreciated .
Regards
