John Deere 2629.04 – Engine Control Unit (ECU): Fixed Turbocharger Compressor Outlet Temperature Signal Out of Range Low

The control module is receiving a signal voltage from the compressor outlet temperature sensor that is too low (typically less than 0.5V). This condition almost always indicates a short to ground in the sensor circuit, a broken wire, or a completely failed sensor. When active, the engine may derate or limit performance to prevent perceived overheating damage.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8R Series
• 8RT Series
• 8RX Series
• 8245R
• 8400R
• 8310RT
• 8335RT
• 8360RT
• 9R Series
• 9RT Series
• 9RX Series
• 9410R
• 9460R
• 9510R
• 9560R
• S-Series Combines
• S680
• S685
• S690
• 7000 Series Forage Harvesters
• 7180
• 7280
• 7380
• 7480
• 7580
• 7780
• 7980
• 744K
• 824K
• 844K

1. 1

   Examine the compressor outlet temperature sensor and its wiring harness for signs of chafing, melting, or physical damage.

2. 2

   Use a multimeter to check the voltage at the sensor connector (a reading below 0.5V triggers this code).

3. 3

   Test the circuit for continuity to ensure there are no unwanted paths to ground (short to ground).

4. 4

   Remove the sensor and check if it is heavily plugged up with soot or carbon.

5. 5

   Note: If a new sensor does not resolve the code, the issue is highly likely a broken wire or short in the engine wiring harness rather than the sensor itself.

1. 1

   Power Down

   Turn off the engine, remove the key, and disconnect the battery to ensure safety and prevent electrical spikes.

2. 2

   Locate the Sensor

   On twin-turbo engines, the sensor is located on the interstage compressor air duct (the tube between the two turbos). For example, on a 9460R, it is found on the 4-inch U-shaped intake tube.

3. 3

   Disconnect

   Unplug the electrical connector from the temperature sensor.

4. 4

   Remove

   Use a wrench to carefully unscrew the faulty sensor from the air duct.

5. 5

   Install

   Thread the new OEM temperature sensor into the air duct and tighten it to the manufacturer's torque specifications.

6. 6

   Reconnect

   Plug the electrical harness back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Clear Codes

   Reconnect the battery, turn the ignition on, and use a diagnostic scan tool to clear the ECU 002629.04 fault code.

8. 8

   Test

   Start the engine and run it under operational conditions to verify the code does not return.