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ElectricalSeverity Medium: diagnose soon

P0622Generator Field "F" Terminal Control Circuit

What it means

The ECU sees a fault in the alternator field ("F") control circuit.

Symptoms

  • Battery light on
  • Low charging voltage

Common causes

  • Faulty regulator or brushes
  • Wiring fault
  • ECU fault

What to check first

  1. Check charging voltage
  2. Check the field control wiring
  3. Bench-test the alternator
Can I drive with P0622? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0622: questions and answers

What does P0622 mean?

P0622: Generator Field "F" Terminal Control Circuit. The ECU sees a fault in the alternator field ("F") control circuit.

What are the symptoms of P0622?

Battery light on. Low charging voltage.

What causes P0622?

Faulty regulator or brushes. Wiring fault. ECU fault.

How do you diagnose P0622?

1. Check charging voltage 2. Check the field control wiring 3. Bench-test the alternator

Can I drive with P0622?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.