EGR differential pressure sensor high
The signal wire is seeing more voltage than the circuit should ever produce — usually the signal wire touching battery power or the 5 V reference.
SPN 411 — EGR differential pressure sensor high
SPN 411 is the parameter the ECM is flagging on Volvo engines. The FMI that comes with it tells you how it failed. Each failure mode below has its own causes and its own test order — do not treat them as the same repair.
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Every SPN and FMI page on this site stays open — no account needed. Pro members can take the code into Blue Collar AI with the VIN, symptoms and photos, keep per-truck history, and print a work order. $14.99 a month or $99.99 a year.