John Deere 2630.03 – Engine Control Unit (ECU): Charge Air Cooler Outlet Temperature Input Voltage Problem / Exhaust Gas Recirculation (EGR) Fresh Air Temperature Sensor Input Voltage Too High

The input voltage to the EGR fresh air temperature sensor (or charge air cooler outlet temperature sensor) exceeds the maximum specified limit. This typically indicates a short to 12 volts or an open circuit in the sensor's wiring harness, signal wire, or ground wire, causing erroneous temperature readings that can lead to engine derate.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 7430 Premium
• 7630
• 7730
• 7830
• 7930
• 9230
• 9330
• 9430
• 9530
• 9630
• 9660 STS
• 9760 STS
• 9670 STS
• 9770 STS
• 7250
• 7350
• 7450
• 7550
• 7750
• 7850
• 4930 Self-Propelled Sprayer
• 3520
• 540G-III
• 548G-III
• 540H
• 548H

1. 1

   Visually inspect the sensor wiring harness and connectors for any signs of damage, corrosion, or an open circuit

2. 2

   Use a multimeter to measure the voltage at the sensor connection (a reading higher than the specified limit confirms a short to 12V or an open circuit)

3. 3

   Check the coolant level (a low coolant pump that is air-locked can cause low flow through the low-temperature cooling circuit)

4. 4

   Ensure the charge air cooler and radiator are not plugged with debris

1. 1

   Repair Electrical Faults

   If the multimeter test reveals a short to 12V or an open circuit in the harness, repair or replace the damaged wiring/connector.

2. 2

   Test/Replace the Sensor

   If the wiring is intact, the sensor itself has likely failed internally. Disconnect the wiring connector, remove the faulty sensor, coat the new sensor's O-ring with high-temperature grease (e.g., JDT 405), and install the new sensor tightened to OEM specifications.

3. 3

   Bleed the Low-Temperature Cooling (LTC) Circuit

   If applicable, fill the coolant reservoir to the 'MAX' fill line. Open the bleed valve while running the engine without load for 5 minutes at 1700 rpm. Shut the engine off for 5 to 10 minutes before closing the drain valve. Recheck the coolant level and repeat if it drops below the 'MAX' line.

4. 4

   Clear Codes

   Restart the engine or use a diagnostic tool to reset the ECU communication messages and clear the fault code. Test the machine under load to ensure the code does not return.