Massey Ferguson E1761.03 – Engine ECU: DEF Tank Level Sender High Voltage

Signal voltage from the Diesel Exhaust Fluid (DEF) tank level sensor is exceeding the normal operating range. The underlying condition is typically a short circuit to a high source (12V) or an open circuit in the sensor or its wiring harness.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Inspect the wiring harness from the DEF tank level sensor to the Engine ECU. Look for chafed wires, disconnected plugs, or corrosion that could cause an open circuit or a short to a 12V power source.

2. 2

   Use a multimeter to test the sensor circuit for continuity to ground and to verify that the signal wire is not shorted to battery voltage.

3. 3

   Plug in a known-good DEF tank level sensor (if available) without installing it in the tank. If the fault code changes from 'Active' to 'Inactive' (or changes to a low voltage code), the original sensor is defective.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the battery to prevent electrical spikes.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a broken wire or a short in the harness, repair the damaged section using weather-sealed connectors, or replace the affected harness section.

3. 3

   Replace the Sensor

   If the wiring is intact, the DEF tank level sensor itself has failed internally. Drain the DEF tank below the level of the sensor/header unit. Disconnect the electrical connector and the DEF fluid lines from the DEF header unit on top of the tank. Unbolt the retaining ring or mounting bolts securing the DEF header to the tank. Remove the old DEF header assembly. Install the new DEF header assembly, ensuring the gasket/O-ring is properly seated to prevent leaks. Reconnect the fluid lines and electrical connector.

4. 4

   Clear Codes

   Reconnect the battery. Using a diagnostic service tool (like WinEEM4 or AGCO EDT), save the error log, erase the inactive codes, and restart the ECU/cycle the ignition to verify the fault does not return.