Diesel Data: Automotive Repair

General Information





Engine Control
P0625 Generator Field/ F Terminal Circuit Low - General Information

Component Location





General Description

Alternator in which there is a communication regulator in order to compensate current loss resulting from repetitive starting. The alternator is duty controlled as current control by ECM with the battery voltage, current, temperature information from battery sensor. The more electrical load, the higher duty output.

DTC Description

ECM sets DTC P0625 if the ECM detects that the alternator's output duty signal is 50%.

DTC Detecting Condition





Diagnostic Circuit Diagram










Signal Waveform & Data








Fig 1) Idle Status
Fig 2) Electrical Load (Head Lamp and Defrost are ON
Duty(+) from FR terminal is increased if electrical loads are ON(Head Lamp and Defrost are ON) ECM controls generation of alternator with duty from FR terminal when electrical Loads turn on