Monitor ECU Engine Control Unit for John Deere 490E & Hitachi EX120-3

Fits Models At A Glance:

• John Deere Excavators: 490E*
• Hitachi Excavators: EX120-3

Key Notes:

• Part Numbers: AT158401, 9109825
• Type: Monitor / ECU — Engine Control Unit
• Weight: 3 lbs
• Application: Engine control unit — manages engine performance, monitors operating parameters, and communicates with the machine's control systems on the John Deere 490E and Hitachi EX120-3 excavator
• Condition: Aftermarket replacement part
• Location: Cab — instrument panel / engine control system

Common Use Case or Symptoms: Use Case: Resolves ECU-related issues including engine shutdown, erratic performance, fault codes, or monitor display failure on the John Deere 490E and Hitachi EX120-3.

⚠️ Important Fitment Note: The John Deere 490E uses either an EX120-2 or EX120-3 style controller depending on serial number. Machines with serial numbers below 24999 require the EX120-2 controller. Machines with serial numbers 25000 and above require the EX120-3 controller. These are not interchangeable. Please verify your serial number before ordering.

Why Choose Broken Tractor:

• ✅ Serial Number Verified Fitment — Cross-referenced against AT158401 and 9109825 for the John Deere 490E and Hitachi EX120-3
• ✅ Get Your Machine Reading Right — Restores proper engine monitoring and control so your excavator runs as designed
• ✅ Ships Fast from the U.S. — In-stock and ready to dispatch from our U.S.-based team