w221 check engine light p0071
#1
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2010 SLK 350
w221 check engine light p0071
hey all,
Driving my 2008 S550 today the engine light turns on.
engine scan shows p0071 (ambient air temp sensor
range performance)
the temp on the dash reads +7c
then I checked what the reading on the dash was in my slk and it was +1
Im having a hard time finding the air temp sensor on the bumper.
there is a spot for it near the left fog lamp but no sensor or harness or plug?
does the w221 read off the map sensor for ambient temp?
thanks
Driving my 2008 S550 today the engine light turns on.
engine scan shows p0071 (ambient air temp sensor
range performance)
the temp on the dash reads +7c
then I checked what the reading on the dash was in my slk and it was +1
Im having a hard time finding the air temp sensor on the bumper.
there is a spot for it near the left fog lamp but no sensor or harness or plug?
does the w221 read off the map sensor for ambient temp?
thanks
#2
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Join Date: Nov 2013
Location: Northampton PA
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99 E 300TD, 02 E320, 2013 ML350
No, it does read the ambient temp sensor. It is located in the bumper and can be hard to locate. A lot if times water will enter the sensor and give a false reading. Another common problem is the sensor will become detached from its mounting and may rest closer to the engine also giving a false reading
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asdqwe33w (04-12-2016)
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2010 SLK 350
thanks. thats what thought.
i have changed them before on c class and e class even w220 but not on w221
I can see on the bumper where it mounts.
I have pulled the front bumper to find the sensor thinking it had fell behind but like i said there is no trace of it being there.
not even a harness or plug.
weird....
is there another spot?
i have changed them before on c class and e class even w220 but not on w221
I can see on the bumper where it mounts.
I have pulled the front bumper to find the sensor thinking it had fell behind but like i said there is no trace of it being there.
not even a harness or plug.
weird....
is there another spot?
#5
I had the P0071 error message and ordered a new sensor. The new sensor arrived this week and I installed it today. My sensor was detached from the mount when I removed the front bottom engine cover. I am attaching a few pictures.
![](http://postimg.org/image/51fkr2ddp/)
![](http://postimg.org/image/u35nxoxjl/)
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mercedesbenzs55 (04-12-2016)
#7