Fault Phenomenon: SANY SY5500THB fuel system functions normally when cold. With a half-full tank (operating temperature), fuel supply is insufficient, engine surges, and eventually stalls.

Troubleshooting Process:
– Checked fuel tank: tank not deformed, no impurities.
– Checked fuel lines: lines not bent, no leaks.
– Checked fuel pump: pumping pressure normal, no leaks.
– Measured fuel tank level sensor at operating temperature: found sensor signal error.

Root Cause: The fuel tank level sensor float sticks due to heat, causing an incorrect fuel level reading.

Required Parts: Fuel tank level sensor.