حساس ضغط محلول المعالجة معيب

The sensor measuring reductant delivery pressure, faulty. Dosing is metered by pressure and time, so the module needs this reading to know what quantity it actually delivered.

A wrong reading means dosing that is wrong in a plausible direction. Reading low, the module raises pressure and over-doses, producing crystalline deposits and high consumption; reading high, it under-doses and conversion falls. Neither presents as a sensor fault. Compare commanded against actual pressure across a dosing event, and check the line and filter first — a restriction gives a genuinely wrong pressure with a perfect sensor. Crystallised deposits at the sensor port are common and isolate it from the fluid, which is the same failure as a blocked exhaust pressure port.