Thermo King TS500 03 alarm code

[ts_ber]

My Thermo King (TS500) shows 03 error code. I found where is Return Air Sensor. My sensor is with number 412649 but it is graded (4L). What is the procedure to change it?

[trinialex]

Hi take the defective one out,wiring the new one....Enter Guarded Access....Configuration/Sensors.....Change to 4L.