Cooling fans run continuously on high W166
Thread Starter
Member
Joined: Nov 2017
Posts: 75
Likes: 30
ML63 W166
Cooling fans run continuously on high W166
I Have a W166 2014 ML63
my cooling fans come on about 10 seconds after start up and stay on. full blast . (ambient 19 Celsius /66 Fahrenheit )
air conditioner is OFF (although the fresh air vent blower was on)
I noted the Green start / stop light was no longer lit on my dash. (no ECU light or any other unusual light lit up)
I noticed the temperature gauge was down low/cold and after 5 minutes of driving the temperature was back to normal but the fans are still on full blast.
I stopped for 15 minutes then started up and again temp was low/cold but built up quick after 5 minutes of driving, fan still on full blast.
car seams to be running fine, and the transmission is hanging onto gears a little longer than normal
fitted the iSoft MB OB2 analyser result is P050C64
"the coolant temperature of the combustion engine is implausible during a cold start. there is an implausible signal "
Control Unit MED177_M157-CAN
MB number 2789011300
P050C Cold Start Engine Coolant Temperature Performance (obd-codes.com)
dealer suggests there has been a lot of problems with the resistor in the fan
when i get a result ill post the outcome as it may help someone else with the same problem
Anyone with any wisdom they can share?
my cooling fans come on about 10 seconds after start up and stay on. full blast . (ambient 19 Celsius /66 Fahrenheit )
air conditioner is OFF (although the fresh air vent blower was on)
I noted the Green start / stop light was no longer lit on my dash. (no ECU light or any other unusual light lit up)
I noticed the temperature gauge was down low/cold and after 5 minutes of driving the temperature was back to normal but the fans are still on full blast.
I stopped for 15 minutes then started up and again temp was low/cold but built up quick after 5 minutes of driving, fan still on full blast.
car seams to be running fine, and the transmission is hanging onto gears a little longer than normal
fitted the iSoft MB OB2 analyser result is P050C64
"the coolant temperature of the combustion engine is implausible during a cold start. there is an implausible signal "
Control Unit MED177_M157-CAN
MB number 2789011300
P050C Cold Start Engine Coolant Temperature Performance (obd-codes.com)
dealer suggests there has been a lot of problems with the resistor in the fan
when i get a result ill post the outcome as it may help someone else with the same problem
Anyone with any wisdom they can share?
Thread Starter
Member
Joined: Nov 2017
Posts: 75
Likes: 30
ML63 W166
SOLUTION PENDING. for those interested or who may come up with the same problem.
I was all prepared to replace the coolant temperature sensor and when i went to put the car up on the ramps to start work HEY PRESTO problem was gone.
WHAT DID I DO?? removed the left air filter to do some investigation as to the location of the coolant temperature sensor (located below the left hand head)
ALSO pushed the connector to the fan which was in place (but the moving of the connector I believe was the solution) this indicates potentially a poor connection at the plug and probably result in a reoccurrence of the problem.
SO if this problem occures again , hopefully i know where to look, I put the OB11 analyser on to check codes and noted the fault codes had cleared.
I was all prepared to replace the coolant temperature sensor and when i went to put the car up on the ramps to start work HEY PRESTO problem was gone.
WHAT DID I DO?? removed the left air filter to do some investigation as to the location of the coolant temperature sensor (located below the left hand head)
ALSO pushed the connector to the fan which was in place (but the moving of the connector I believe was the solution) this indicates potentially a poor connection at the plug and probably result in a reoccurrence of the problem.
SO if this problem occures again , hopefully i know where to look, I put the OB11 analyser on to check codes and noted the fault codes had cleared.
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,749
Likes: 880
From: In the Shadow of the Tetons
2013 ML350 Bluetec
A bad connector would certainly yield the implausible signal that the computer was complaining about.
Side note: every time I take an electrical connector apart under the hood I spray both sides with silicone lube. Seems to have ended electrical woes for me.
Side note: every time I take an electrical connector apart under the hood I spray both sides with silicone lube. Seems to have ended electrical woes for me.
