Which engine system has failed?

• A. N2 Gear Train
• B. VARTOMS
• C. Fuel Pump Assist
• D. Engine Control Unit

Answer: (B)

Timing coordination and monitoring is what the scenario is pointing to. VARTOMS is the system that manages the timing of valve events and related engine timing functions to ensure proper combustion and performance. When this system fails, timing becomes off, which typically shows up as power loss, rough running, or timing-related instability—distinct from failures in other areas. The N2 gear train drives engine accessories; its fault would mainly affect accessory power or drive, not timing. The fuel pump assist failure would cause fuel delivery problems, especially at start or high demand, not timing issues. The engine control unit failure would disrupt electronic management more broadly, often triggering fault codes or limp mode. Because the symptoms described align with a timing/valve-control fault, VARTOMS is the best match.