P0622
Generator Field/F Terminal Circuit
Charging system
Generic OBD-II
High
What it means
P0622 means the ECM detected a fault in the generator (alternator) field 'F' terminal circuit, which the module uses to control charging output. A problem here can stop the battery charging properly and turn on the charging warning light. It is usually a wiring, alternator, or battery issue.
High
Can I keep driving? Limit driving — if the battery isn't charging you can be left stranded once it drains, and electrical systems may act up. Get it checked soon.
Common symptoms
What you'll notice
- Battery / charging warning light on the dash
- Battery discharges or won't hold a charge
- Dim lights or erratic electrical accessories
- Difficulty starting as the battery weakens
Common causes
Most likely first
- Damaged or corroded wiring in the generator field circuitLikely
- Loose or poorly connected field/F terminal wiringCommon
- Failed generator (alternator)Common
- Weak or failed batteryLess often
- Failed engine control module (ECM), least likelyLess often
How to diagnose & fix
Work through it in order
- Test battery and charging-system voltage with the engine running (should be roughly 13.5–14.5 V).
- Inspect the generator field/F terminal wiring and connector for corrosion, looseness, or damage.
- Load-test the battery and replace it if weak.
- Test the alternator's output and field control; replace the alternator if it fails.
- Repair the field circuit wiring, then clear and re-test charging.
FAQ
Quick answers
Is it safe to drive with P0622?+
Only for short distances. If the alternator isn't charging, the car runs off the battery and will eventually stall. Address it before longer trips.
Can I just clear P0622?+
It will return while the field circuit or alternator is faulty. Clearing it won't restore charging — repair the cause.
Related codes
Often seen with P0622
Read & clear P0622 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX