Hello

Please help me to locate the sensor to fix the trouble code P010617

B28/7 "pressure sensor Downstream of the throttle valve

Part number if possible, and where this sensor is located.

Thank you

Wow, it's literally on page 1 of threads. Does anyone do any research themselves anymore? Seems like all most know how to do anymore is ask someone else how to do something.

https://mbworld.org/forums/e-class-w...e550-m278.html

Lol geez I tell ya!

I did research, I found a similar topic but for AMG version. I was looking by trouble codes, not by MAP sensor issues and that was my mistake

Thank you!

The M157/M278 are the same platform, and share most common parts. So parts location will be the same, year per year (engine wise).

For the reference

Hello again

I replaced the sensor but still have trouble codes, please see the attached

Please help me out, thank you

Check the ECU pins for oil contamination. If oil is found, your harness may be compromised.

Just checked, no oil was found.

Any other ideas?

Is the B28/7 you got as replacement a genuine one ?
1,111hpa of air pressure ( engine off ) means that is supposedly ambient pressure.
Normal condition , at sea level is 1,013 hPa or millibar or 101,325 Pa, same-same.

Your sensor is reading your engine being underground at -783 meters. Type in 111,100 Pa
https://www.mide.com/air-pressure-at...ude-calculator

The car was idling during test, and yes I bought the OEM senor

The B28/7 should read vacuum at idle or 370 to 450 hPa there about.

Was the old assumed defective B28/7 sensor also reading the same wacky value at idle ?


Turn engine OFF, keep ignition ON so ECM is running.
Try to use vacuum pump to exercise the membrane of B28/7. Who knows it is stuck.

Unplug B28/7 from its position and let it read ambient atmospheric pressure. Read the pressure value, it should read ambient pressure like all other MAP/Pressure sensors B28/4 , B28/5 and B28/6 are reporting. +- 3 or 4 hPa is okey.
Use vacuum pump to create vacuum to B28/7 and see does it come close to the vacuum gauge reading ( yes, you must convert )

If still B28/7 alone is reading funny/error, simplest way is to use the other MAP/pressure sensors to take place of B28/7 to confirm IF wiring to B28/7 is the problem or the sensor itself.
The closest specification would be the B28/6, but if reading ambient atmospheric pressure only, all other 3 sensors would surely match.
No need engine running, just read ambient pressure with engine OFF and ignition ON.

Good luck

Problem solved

Thank you for your help, the issue was caused by my racechip. After software update readings came back to normal.

Good to hear you found the problem.

However : Wow.... that is a scarry boost manipulation value.
Assuming 1,111 hPa at idle represents the boost manipulation gross value (at sea level), that is approx 600 hPa or 0.6 BAR or 9 psi of extra ACTUAL turbo boost under reporting.
M278 DELA46 standard boost is 0.9 Bar ( 13psi ).... holy cow, 66% manipulated extra turbo boost.

I am wondering, piggy back black box like RaceChip manipulation method, where and when the manipulated data is injected ?
At idle surely it won't manipulate anything significantly...yet, otherwise DTC code willl be generated by the engine ECM for whacky values....as you are experiencing.

RaceChip can't manipulate orginal fuel/boost/ignition/etc mapping of your ECM, it can only under-report value of the sensors to the ECM.
Something has to give.... I think the CAT system will suffer in the long term if the cheat is too crude.
I guess the plastic intake manifold and aftercooler can handle extra 9psi of pressure ?
Turbo wise, I don't know if extra 9psi will shorten its life by X% ?

M271.860 of 184HP uses 1.2 BAR boost or 17.4 psi.

Bumping this old thread. What exactly did you update to fix this? The racechips or the Benz?
thanks.