P0247

P0247 indicates a general electrical fault in the turbocharger wastegate solenoid B control circuit, used on twin-turbo, twin-scroll, or sequentially-staged setups where solenoid B controls the secondary or rear-bank wastegate. Cheapest path: identify which physical solenoid is B on your platform (often the rear or passenger-bank unit on V-configuration twin-turbos), then unplug it and measure resistance across the terminals, expecting 14-30 ohms on most applications. Inspect the connector for oil contamination from upstream turbo seal weep, a leading cause on high-mileage twin-turbo engines. The expensive misdiagnosis is condemning the secondary turbocharger ($1,500-$3,000 plus labor) when bank-correlated codes like P0247 almost always trace to the cheaper solenoid or its harness.

Vehicle-specific patterns: 2007-2010 BMW 335i/535i N54 twin-turbo throws P0247 on the rear-bank wastegate solenoid that fails from oil ingestion via the PCV; 2010-2016 Ford F-150 3.5L EcoBoost (twin-turbo) right-bank wastegate solenoid harness chafes on the turbo coolant line (TSB 15-0117); 2014-2019 Audi S4/S5 3.0T rear bypass actuator solenoid shorts internally after coolant exposure; 2008-2013 Nissan GT-R VR38DETT secondary wastegate solenoid loses its connector lock-tab and unplugs under track use. Estimated repair: $140 to $580.