John Deere Fault Code
Free · no signup639.13
Dash display goes "blank" or shows "No Comm"; Machine may stay at idle.
System
ECU
Symptom
Dash display goes "blank" or shows "No Comm"; Machine may stay at idle.
Diagnosis & fix steps
CAN Bus J1939 Data Link Error.
LOGIC: The ECU and ICU (Monitor) have lost communication with each other.
ACTION: 1. Check for 60 ohms between CAN High and CAN Low.
2. Inspect the "Terminating Resistor."
3. Check the harness at the cab-to-frame bulkhead.
FIX: Repair broken CAN bus wires; replace failed Terminating Resistor.
Red Seal field insights
Check the battery terminals first! Low voltage or a loose ground can "crash" the CAN bus and make it look like a controller has died when it's just a bad connection.
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