Deutz-Fahr 486 – ECU: Gear Oil Temp Sensor Signal High

The engine's electronic control unit (ECU) has detected that the voltage signal from the gearbox oil temperature sensor is above the maximum expected threshold. This indicates that the signal range has been exceeded, compromising the sensor's ability to provide accurate temperature readings. This condition typically suggests a short circuit to a positive voltage source.

• TCD 2012
• TCD 2013
• BFM 1013
• BFM 2012
• 912
• 913
• 914
• 1011
• 2011

1. 1

   Visually inspect the wiring harness connected to the gearbox oil temperature sensor for chafing, breaks, corrosion on the connectors, or loose connections

2. 2

   Check the sensor's wiring for a short circuit to a positive voltage source (battery positive) or to other wires in the harness

3. 3

   Test the sensor's internal resistance when disconnected and compare it to manufacturer specifications to determine if the sensor itself has failed

4. 4

   Reset the ECU by switching the vehicle's ignition off, waiting at least 30 seconds for the ECU to completely power down, and then switching the ignition back on to check if the fault code reappears

1. 1

   Confirm fault source

   Perform the wiring and resistance diagnostic checks to confirm whether the sensor itself or the wiring harness is the root cause of the error.

2. 2

   Locate and prepare for removal

   Locate the threaded sensor on the transmission or gearbox housing. Disconnect the negative battery terminal to prevent electrical issues and place a drain pan underneath to catch any leaking gear oil.

3. 3

   Remove the faulty sensor

   Disconnect the electrical connector and use an appropriate size wrench to unscrew and remove the old sensor.

4. 4

   Install the new sensor

   Ensure the new sensor's threads are clean and apply sealant if specified by the manufacturer. Thread the new sensor in by hand to avoid cross-threading, then tighten it to the specified torque without overtightening.

5. 5

   Finalize and reset

   Reconnect the electrical connector and the battery. Top off the gear oil if a significant amount was lost. Reset the ECU by switching the ignition off, waiting at least 30 seconds for the ECU to power down, and then switching it back on.

6. 6

   Verify repair

   Start the engine and allow it to warm up. Check for any leaks around the new sensor and verify that fault code 486 does not return.