Thermo King Truck/Trailer Refrigeration Unit Error Alarm 51: Causes & Fixes
Check Shutdown Circuit
Check Shutdown Circuit
Check Heat Circuit (Zone)
Check Economizer Valve Circuit
Check Belts or Clutch
Check Spare Sensor 1
Reset Clock
Check Hot Gas or Hot Gas Bypass Circuit
Check Air Flow (Zone)
Remote Sensor Shutdown
Unit Forced to Low Speed
Unit Forced to Low Speed Modulation
Check Fuel System
Check Water Valve Circuit
Check High Speed Circuit
Check Engine Coolant Temp
Electric Motor Failed to Run
Check Engine Coolant Level
Electric Phase Reversed
Check Engine RPM
Check Modulation Circuit
Check Run Relay Circuit
Defrost Damper Stuck Closed (Zone)
Check Oil Pressure Switch
Refrigeration Capacity Low (Zone)