Mercedes OM270 engine fault P0299 relating to turbocharger boost pressure too low, causing reduced power, limp mode and engine warning light.
Fault code P0299 was stored for turbocharger boost pressure too low.
Live data testing confirmed the engine was not achieving the specified boost pressure under load.
Boost hoses and intake pipework were pressure tested and checked for leaks. Wastegate and turbo actuator operation were also inspected.
After ruling out boost leaks and control faults, testing confirmed the turbocharger itself was faulty.
The turbocharger was replaced and boost pressure returned to normal operation.
P0299 is commonly caused by boost leaks or boost control faults rather than turbocharger failure. Full boost system testing should always be carried out before replacing the turbocharger.