551 Error Code For Avery Tractor Models
There are 2 kind of error description.
Hand Throttle (STD cab) Idle Validation Switches are both open
Foot Throttle Idle Validation Switches are both open (engine controller pins B25, B26)
Partial frosting and sweating of lines combined with poor cooling, fan belt slipping, loss of refrigerant, restricted or clogged liquid line or expansion valve malfunctioning.