Gents,

Calibenz told me about the mod on charge air cooler coolant pump re-wired to run much sooner than its supposedly 45C or so trigger temperature.
I was looking at the mod at this thread : https://mbworld.org/forums/w212-amg/...ewiring-3.html

I took a closer look at my logs and found that it seems my M276.820 3.0T which the ECM is also a MED 177 family like M278 and M157 , won't register higher than 60C Intake Air Temperature.
I know when being heat soaked after engine kill it is very hot the engine bay.

I am wondering if anyone has a OBD2 logged data showing M157 Intake Air Temp going higher than 60C / 140F ?
I mean this data is from the ECM, so it should be able to be logged under OBD2.

I know some of my sensors when connector disconnected will use a SUBTITUTED value, example the HP Fuel Pressure + Temp sensor.
There is no DTC or issue on my ECM ever, for IAT sensor. I am using Benz Ninja Xentry and a few other scanners from Launch and Autel and Xtool...none ever logged any DTC for IAT sensor.


Here is what my log is showing. This is from a Banks Gauge where I add extra modules to show other data like pressure and temperature not from ECM-OBD2, but the log combined them.

I am seeing 60C as max in all of the logs and I am sure it should be higher when engine kill and heat soaked , at engine start or creeping 1 MPH traffic jam.




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Charge air cooler water/coolant temperature at Column AN shows 64.1C / 147F.
That is K thermocouple base temperature sensor at the skin of the pressure sensor for the charge air cooler water pump ( by Banks ) and is at the COOLED side of the coolant after the aftercooler's radiator.
So from this point the coolant will be sent to the air-to-water heat exchanger to cool the intake air temperature.
However when car is not moving or at traffic jam creeping slow, that skin based K thermocouple will be heat contaminated by the ambient air of the engine bay/under-hood,
thus it shows hotter than Intake Air Temperature. But again if the intake air temp sensor max limit is 60C by data, it is a question I am requesting assistance from M157 owners for data comparison.
I have seen drifted value of temperature sensor, but I have yet seen a locked-Max Out one at 60C
I will replace that IAT temperature sensor soon though, just to be sure and more so when your M157 can show higher than 60C.




Thanks in advance ....

 

Read post 33:

https://mbworld.org/forums/w212-amg/...venture-2.html

he determined his ic pump was not working

https://mbworld.org/forums/w212-amg/...an-logs-4.html

 

Here's what I got ...

MOTUL RACE TRACK OIL... 5W-40 👍

besides IAT went up to 102°C so it's not truely limited... heatsoak in Jakarta should bring a significant bump, right?
Something new to be discovered there... bad GND Ref.

 

Wow ! 102C dang !!!
Thanks very much Peter.

So my AIT sensor got stuck at 60C.... LOL. Man, why weird issue..... ha ha ha.

I so happened to have bought a new one years ago and I forgot about it.
I did a quick test, engine OFF ignition ON and the new AIT sensor + K thermocouple and heat gun. I got 67C and stop, enough confirmation already.









.
Now the old sensor is kinda stuck, I can't turn the rest of the 30 degrees or so CCW to open or ready to pull-out condition.
I have removed the sensor before some years ago, but the aftercooler was out of the engine bay and it was not the smoothest locking mechanism ... but do able.
Today I fear AIT sensor will break inside its cavity if I force it and the working space is very bad and angled.
So I need to undo my aftercooler to replace the AIT sensor ..DUGGGH !!!






Thanks to Calibenz asking me to read the aftercooler pump mod thread and this led to me discovering I have a stuck at 60C AIT sensor..
who could have guessed such failure mode.

.

 

I feel like a total idiot !!!!
I kept believing CCW for 90 degrees is total unlocking of the IAT sensor internal latches (2).

I looked at my old archive of 2021 photos and it was only 45 degrees, and my AIT sensor is not stuck, it have reached its end of CCW travel.
The pulling UP-OUT is rather "heavy" and hence I thought I have not done enough CCW rotation...Duggghhh !!!!

All good now, AIT sensor replaced already.

Correction is below :