Coolant Temperatures sensor
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From: San Jose, Ca
2005 ML350
Coolant Temperatures sensor
Hi, I'm still puzzling over my temp gauge. Not sure if the coolant temperature sensor is defective or not? I have replace this thing before (almost 2 years ago) but when I perform a scan the readings are as followed:
-044 B1 2/2 (Refrigerant pressure and temperature sensor) 6 bar
-045 B1 2/2 (Refrigerant pressure and temperature sensor) 158 degree F.
Base on the scan data 158F translate to 70C. But my temp gauge was at 90C. There is a difference of 20Degree C. Does this mean my sensor is shot? Any comments are appreciated! Thank you
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2002 ML 320 & 2006 ML500
You are confusing the Coolant Temp. Sensor with the Refrigerant Pressure/Temp Sensor, the latter of which has nothing to do with the eng. temp.
Last edited by Maj. Dundee; Mar 1, 2018 at 06:20 AM.
Thread Starter
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Joined: Jan 2018
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From: San Jose, Ca
2005 ML350
Maj.
I'm not sure if I ask you this, but can you show me the correct procedure to check if both the fans in front of the radiator are working properly by removing the relay and performing jumper. I come to believe that my wiring harness might be damage somewhere in between the connector at the fans and aam modules where the relays and switches are.
I like to know if my radiator is working or not. How do i know if it is working properly?
Lastly, when i'm driving and with AC turn on i can hear my air compressor engaged. It creates a errr sound. Afterwards, this errrr sound continue to be hearing from inside the car while driving. Could it be the bearing on the ac compressor about to be going bad? If so, can I swap the bearing out?
Many Thanks
I'm not sure if I ask you this, but can you show me the correct procedure to check if both the fans in front of the radiator are working properly by removing the relay and performing jumper. I come to believe that my wiring harness might be damage somewhere in between the connector at the fans and aam modules where the relays and switches are.
I like to know if my radiator is working or not. How do i know if it is working properly?
Lastly, when i'm driving and with AC turn on i can hear my air compressor engaged. It creates a errr sound. Afterwards, this errrr sound continue to be hearing from inside the car while driving. Could it be the bearing on the ac compressor about to be going bad? If so, can I swap the bearing out?
Many Thanks
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MBWorld Fanatic!
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From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
To mechanically check the fans, first check to see that fuse 44 is not blown. If not, fashion a short jumper wire with spade terminals attached and remove relay K26.
At the fuse box slots where K26 was, insert ends of jumper wire into slots 30 & 87 and the jumper wire must make contact with a silver contact point in each slot; the fans should run. If so, immediately remove jumper wire.
Below is when the auxiliary fans are supposed to come on depending on the coolant temp. and or the refrigerant pressure. They will not come on until one or both readings are met.
As for the sound that the compressor makes is very difficult without hearing and seeing the compressor operate.
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Thread Starter
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Joined: Jan 2018
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From: San Jose, Ca
2005 ML350
Ok, thanks for the pictures. I will make a wire set as in the picture to test and report back.
As for the AC compressor I have made another video with the AC turn on to hear the compressor
engage and making the whirring sound from inside the car. The compressor disengage and
the whirring noise went away as I turn off the AC. Could it be low refrigerant that made it work harder or
the bearing itself is about to go bad? There is one point last June the AC was blowing warm air and I refill
with a R134 can to the correct pressure.
thanks for any advice.
As for the AC compressor I have made another video with the AC turn on to hear the compressor
engage and making the whirring sound from inside the car. The compressor disengage and
the whirring noise went away as I turn off the AC. Could it be low refrigerant that made it work harder or
the bearing itself is about to go bad? There is one point last June the AC was blowing warm air and I refill
with a R134 can to the correct pressure.
thanks for any advice.
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From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
I couldn't hear any noise, but why did you only turn the blower dial to #2? If you turn the dial to #5 , does it get louder? If so, the problem is with the blower motor or something is stuck in the blower cage.
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From: San Jose, Ca
2005 ML350
If i turn the dial to #5, the air coming out will be louder and i'm concern that the listener might not hear the AC compressor making that whirring sound. If you listen carefully, just before i switch AC off the engine noise is quieter than the AC compressor. If the blower where stuck in the cage, i wouldn't get any air coming out from any vents, correct? Thanks again
MBWorld Fanatic!
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2002 ML 320 & 2006 ML500
I didn't say the blower was stuck. Why couldn't turn the dial to a higher setting to see if the noise increased?
If so, the problem is with the blower motor or something is stuck in the blower cage.
If so, the problem is with the blower motor or something is stuck in the blower cage.
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2005 ML350
When I turn the dial to higher setting, the air flow is stronger and I can't hear the noise from the AC compressor as much. But thanks, I will check and clean the blower if needed and report back. Thank you
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2005 ML350
Ok, while i was at the local mechanic dealing with oil leak problem, they turn the dial to #5 max and rotate the other dial to direct air between leg and center cabin, the aux fans in front of the radiator came on for 5-10 seconds on and off. This test resulted the wiring are intact, relay K26 and fuse all work. This was idling warm. But while the fan came on i check the temp guage wasn't at 100C mark. It was still below that mark. Just wondering why it came on before it reach the mark?
I've tried turning ac dial #5 max before but with the dial control to direct the air to center cabin but the fan does not come on. Could there be another sensor must have gone bad to cause the fan not to come on at this mode? I will test on other mode later today and report.
Thanks,
I've tried turning ac dial #5 max before but with the dial control to direct the air to center cabin but the fan does not come on. Could there be another sensor must have gone bad to cause the fan not to come on at this mode? I will test on other mode later today and report.
Thanks,
MBWorld Fanatic!
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From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
I've tried turning ac dial #5 max before but with the dial control to direct the air to center cabin but the fan does not come on. Could there be another sensor must have gone bad to cause the fan not to come on at this mode? I will test on other mode later today and report.
Thanks,
Thread Starter
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From: San Jose, Ca
2005 ML350
MBWorld Fanatic!
Joined: Oct 2011
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From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Try this, turn the key to pos. #2 and turn the fan dial to 5. Do you hear any noise?
Thread Starter
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From: San Jose, Ca
2005 ML350
Sorry, please disregard the comment that I made that wasn't clear.
Update, turn key to pos. #2 and turn the fan dial to 5. I hear blower motor working to blow lots of air. Very strong. That is all. Am I suppose to expect other noise from this?.
Update, turn key to pos. #2 and turn the fan dial to 5. I hear blower motor working to blow lots of air. Very strong. That is all. Am I suppose to expect other noise from this?.
