Check engine for intake air temp sensor p009812
Thread Starter
Newbie
Joined: Mar 2014
Posts: 8
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1998 c230
Check engine for intake air temp sensor p009812
Hello everyone,
It is always great to fix one thing to then have to deal with something else. Have a 2015 ML350 that I recently did intake manifold gaskets along with spark plugs and ignition coils. Got everything back together and car had no issues. Next day it threw a check engine with code p009812 for IAT has a short circuit to positive. I checked power and resistance to plug and everything looked fine. Tested the sensor and it was readings were off from the ohms specs I found online so I replaced it as it was a cheap enough part. Check engine still came back. I checked the live data of the IAT and after the car sitting outside for hours with the car off the IAT is reading 27°c and the actual temperature outside is about 3°c. I expect some difference in the temperature the IAT shows vs the actual temperature outside since it is within the intake pipe but I assume this is way too far apart. I have tried the basics of unplugging and plugging the sensor back in but also it is a new sensor so I expect it is something else. If anyone has any suggestions on where else to look or anything else to test I would very much appreciate it.
Thank you in advance to any assistance!
It is always great to fix one thing to then have to deal with something else. Have a 2015 ML350 that I recently did intake manifold gaskets along with spark plugs and ignition coils. Got everything back together and car had no issues. Next day it threw a check engine with code p009812 for IAT has a short circuit to positive. I checked power and resistance to plug and everything looked fine. Tested the sensor and it was readings were off from the ohms specs I found online so I replaced it as it was a cheap enough part. Check engine still came back. I checked the live data of the IAT and after the car sitting outside for hours with the car off the IAT is reading 27°c and the actual temperature outside is about 3°c. I expect some difference in the temperature the IAT shows vs the actual temperature outside since it is within the intake pipe but I assume this is way too far apart. I have tried the basics of unplugging and plugging the sensor back in but also it is a new sensor so I expect it is something else. If anyone has any suggestions on where else to look or anything else to test I would very much appreciate it.
Thank you in advance to any assistance!
Newbie
Joined: Jun 2023
Posts: 1
Likes: 0
GLK350
Did you ever find the cause of the code error? I have the exact same issue with my 2015 GLK350. I replaced #1 ignition coil due to ignition code error and after repair the car runs smooth but popped up the same p009812 error for IAT sensor. I replaced it twice and still getting the same error.
