P0620 Fault Code

Generator Control Circuit Malfunction

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0620 fault code indicates a malfunction within the generator control circuit. This circuit is crucial for monitoring and regulating the alternator's output, ensuring that the vehicle's electrical system functions properly. When this code triggers, it may affect the charging system, leading to electrical issues or battery drain.

What are the symptoms of the P0620 code?

The symptoms associated with a P0620 fault code may include:

• Dashboard warning lights, particularly the battery or check engine light
• Difficulty starting the vehicle due to insufficient battery charge
• Electrical accessories malfunctioning or working intermittently
• Battery draining rapidly or not charging properly

What causes the P0620 code?

Common causes of the P0620 code include:

• Faulty alternator or voltage regulator
• Damaged wiring or connectors in the generator control circuit
• Poor ground connections or high resistance in the circuit
• Issues with the vehicle's powertrain control module (PCM) or engine control unit (ECU)

How to fix P0620?

To resolve the P0620 fault code, follow these steps:

• Inspect the wiring and connectors for any visible damage or corrosion, repairing or replacing as needed.
• Test the alternator and voltage regulator to ensure they are functioning correctly.
• Check for proper grounding and continuity in the circuit to eliminate high resistance issues.
• If all components check out, consider reprogramming or replacing the PCM/ECU if it's determined to be faulty.