2012 VW Passat P2279 Fault: Limp Mode, Air Leak Diagnosis & Sensor Wiring Issue

Good afternoon everyone, I'm currently troubleshooting a 2012 Volkswagen Passat 1.6 TDI with a persistent limp mode issue triggered by fault code P2279 — indicating an air leak in the intake system. Initial diagnostics revealed P2279, and I performed both a smoke test and a brake cleaner test to check for external air leaks. Both tests came back negative, confirming no visible or detectable leaks in the intake manifold or associated components. I replaced the original MAF sensor with genuine OEM and Bosch MAP sensors, but the vehicle still returned P2279. Further investigation revealed that the pressure sensor voltage readings were inconsistent — pointing to a broken wire at the neutral position sensor, which connects to the ECM at pin 14. After repairing this wiring issue, the code reappeared. Given that no external air leaks are present and the internal sensors show intermittent signals, I'm now considering an EGR blanking procedure once the engine has cooled down to rule out manifold-to-manifold leaks as a source of false P2279 readings. Has anyone else encountered this specific issue with the 2012 VW Passat TDI? Any additional diagnostics or fixes that have worked in similar cases? Thanks, Tony