P0241

P0241 sets when the ECU reads the boost-pressure sensor 'B' (the secondary turbocharger boost sensor on twin-turbo or sequential-turbo engines, or the post-intercooler boost sensor on some single-turbo applications) and the signal is below its allowable range during a steady-state operating window where boost should be present. The 'B' designation matters: on twin-turbo V-engines, sensor A is bank 1 and sensor B is bank 2, so P0241 is bank-2 specific; on single-turbo applications, 'B' is the second pressure-measurement point in the intake tract. Cheapest-first ladder: (1) Inspect intake/charge piping for blown couplers, cracked silicone hoses, or a popped-off boost reference line at the sensor - a pressure drop at the sensor location with the rest of the system healthy reads exactly as P0241 'low input.' (2) DMM the sensor's 5V reference, ground, and signal wires with KOEO - 5V reference dead means the ECU side or harness is open; reference good but signal stuck near zero means the sensor itself is dead. (3) Check for an exhaust leak ahead of the bank-2 turbo or a stuck wastegate that's bleeding boost off bank 2 before it reaches the sensor - on twin-turbo platforms a partial wastegate failure looks like a sensor fault until you scope actuator position. Expensive-misdiagnosis trap: condemning a turbocharger when the real fault is a $25 silicone coupler or a $90 sensor.

Vehicle-specific patterns: 2007-2010 BMW N54 (335i, 535i, 135i) twin-turbo I6 throws P0241 from a cracked or oil-soaked charge-pipe coupler between the turbos and the intercooler - BMW issued multiple TSBs around upgraded charge pipes and intercooler hoses on this platform. 2011-2016 BMW N63 / S63 twin-turbo V8 (550i, 750i, X5/X6 50i, M5/M6) throws P0241 from boost-pressure sensor B failure on bank 2 along with the well-known coil/injector cluster of N63 issues. 2014-2018 Ford F-150 3.5L EcoBoost twin-turbo throws P0241 from a cracked PCV hose or intercooler tube on the passenger side that bleeds boost off the bank-2 turbo. 2008-2014 Audi/VW 2.0T (CCTA, CBFA, CAEB) with the K03 single-turbo can throw P0241 referencing the secondary intake-tract pressure sensor when the diverter valve diaphragm tears and lets boost vent. Estimated repair: $90 to $1,800