P0622 Code: Generator Field/F Terminal Circuit
🟠 Moderate severity · drivable
Drivable for a short time, but the alternator may stop charging, which will drain the battery and stall the car.
What P0622 means
The engine computer controls the alternator's field circuit, called the F terminal, which adjusts how hard the alternator charges. This code means the field circuit isn't working, so the alternator may not charge the battery.
Symptoms
- Check engine light is on
- Battery warning light on
- Battery drains quickly
- Headlights dim
- Car stalls
Common causes
- most common: Faulty alternator
- common: Failed voltage regulator
- common: Damaged wiring or connector in the field circuit
- less common: Faulty engine computer
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Test the charging system output with a multimeter | Yes | $0–20 |
| Repair the field circuit wiring and connector | Mechanic | $50–200 |
| Replace the alternator | Mechanic | $200–500 |
Frequently asked questions
Can I drive with a P0622 code?
Short distances only. If the alternator stops charging, the battery dies and the car stalls.
What does the F terminal do?
The F terminal is the alternator's field circuit, which the computer uses to control charging output.
How much does it cost to fix a P0622?
Most often an alternator replacement at $200–500 installed; wiring repairs are $50–200.
Related codes
P0621
P0621 Code: Generator Lamp/L Terminal Circuit
P0562P0562 Code: System Voltage Low
P0563P0563 Code: System Voltage High
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.