ECU (Engine Control Unit) 57 means two things: Fuel filter restricted (Solution: change fuel filter) and fuel supply pressure lower than normal (Solution: have your John Deere dealer repair).
See a list of Engine Control Unit Service Codes-(ECU) for 9120, 9220, 9320, 9420, and 9520 tractors here.
To learn how to operate and service your machine correctly, refer to this John Deere Manual.
If a problem is not resolved to your satisfaction, contact the Ag Customer Assistance Center at 1-866-99DEERE (866-993-3373) or e-mail us at agriculture@johndeere.com.
Technical information is available from John Deere. Some of this information is available in electronic as well as printed form. Order from your John Deere Dealer or call 1-800-522-7448 .
For more info, just log on to www.deere.com.
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