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ElectricalSeverity Medium: diagnose soon

P0620Generator Control Circuit

What it means

The ECU sees a fault in the circuit it uses to control the alternator output.

Symptoms

  • Battery light on
  • Charging voltage too low or too high

Common causes

  • Faulty alternator regulator
  • Wiring fault on the control wire
  • ECU fault

What to check first

  1. Check charging voltage
  2. Check the control signal to the alternator
  3. Check the alternator connector
Can I drive with P0620? 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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P0620: questions and answers

What does P0620 mean?

P0620: Generator Control Circuit. The ECU sees a fault in the circuit it uses to control the alternator output.

What are the symptoms of P0620?

Battery light on. Charging voltage too low or too high.

What causes P0620?

Faulty alternator regulator. Wiring fault on the control wire. ECU fault.

How do you diagnose P0620?

1. Check charging voltage 2. Check the control signal to the alternator 3. Check the alternator connector

Can I drive with P0620?

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