OBD-II diagnostic trouble code
P0620Caution
Generator Control Circuit Malfunction
The circuit that lets the ECU control alternator (generator) output has failed, which can affect charging performance even if the alternator itself is fine.
Most searched
Most common OBD-II codes
The check engine codes drivers look up most often, explained.
Powertrain codes
P-Codes
Browse every engine and transmission diagnostic code we cover.
VIN lookup
VIN Decoder
Decode any vehicle's specs and history from its VIN.
Cost calculator
Total Cost of Ownership
See how repair costs like this one add up over years of ownership.
Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
Frequently asked questions
Can I drive with P0620?
You can usually keep driving with P0620, but don't put it off — the underlying cause can get worse or lead to further damage the longer it goes unaddressed. Get it diagnosed as soon as you reasonably can.
How much does it cost to fix P0620?
The cost varies too much by cause and vehicle to give a single figure here — a diagnosis will narrow it down.
What causes P0620?
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief