R350 om642 exhaust back pressure wiring
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Joined: Oct 2025
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W251123
R350 om642 exhaust back pressure wiring
Hello,
my w251123, r350 2012 (om642) is indicating non plausible exhaust back pressure values.
After disconnecting the sensor plug, the same 4800mbar with engine off, remains.
Testing the wire voltages, I see 5v and ground, as expected, yet the sensor signal line indicates 5v, with no sensor connected, yet no continuity between sense line and 5v feed.
I have inspected the connections and loom, and don’t see anything obvious. Does anyone have a clue how the sensor output wire is being fed 5v?, where should I investigate?
Thanks for your time.
my w251123, r350 2012 (om642) is indicating non plausible exhaust back pressure values.
After disconnecting the sensor plug, the same 4800mbar with engine off, remains.
Testing the wire voltages, I see 5v and ground, as expected, yet the sensor signal line indicates 5v, with no sensor connected, yet no continuity between sense line and 5v feed.
I have inspected the connections and loom, and don’t see anything obvious. Does anyone have a clue how the sensor output wire is being fed 5v?, where should I investigate?
Thanks for your time.
Last edited by 1CM; Oct 11, 2025 at 07:01 AM.
