OBD-II Error Code P0625: How to Fix Generator Field Terminal F Circuit Low

Q: Can I drive with error code P0625?

It is not recommended. The battery may not charge, leading to a dead battery while driving. You may experience dim lights, electrical failures, and eventual stalling.

Q: Will replacing the alternator fix P0625?

In many cases, yes, but you should first check wiring and connections. A faulty alternator is a common cause, but damaged wires or a bad PCM can also trigger this code.

Q: What does 'generator field terminal F circuit low' mean?

The PCM detects that the voltage at the alternator's field terminal (which controls charging output) is lower than expected. This indicates a problem in the alternator's internal circuit or the wiring to/from the PCM.

Q: How do I test the alternator field circuit?

Use a multimeter to measure resistance between the field terminal and ground. Normal resistance is 2-5 ohms. Also check for voltage at the field terminal with the engine running (should be close to battery voltage).

Q: Is P0625 the same as P0620?

No. P0625 is specific to the generator field terminal F circuit low, while P0620 is a generic generator control circuit malfunction. Both relate to charging system issues but have different diagnostic paths.

Abstract

Error code P0625 indicates that the PCM has detected a low voltage condition in the generator (alternator) field terminal F circuit. This typically means the alternator is not charging the battery properly, which can lead to a dead battery or electrical issues. The problem is often caused by a faulty alternator, damaged wiring, or a bad connection.