John Deere 1761.01 – ECU: DEF Tank Fluid Low / DEF Tank Empty

The Diesel Exhaust Fluid (DEF) tank fluid level has fallen below the critical warning level (extremely low or empty).

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6R
• 7R
• 8R
• 8RT
• 8RX
• 9R
• 9RT
• 8345R
• 8RT 370
• 9470RT
• 9520RT
• S680
• T670
• W540
• W550
• 331G
• 333G
• 130G
• 160GLC
• 210GLC
• 350GLC

1. 1

   Verify the actual fluid level in the DEF tank (an empty tank is the most common cause)

2. 2

   If the tank is full, check the DEF Tank Level Sensor (integrated into the header) for sticking, crystallization, or internal failure

3. 3

   Inspect the wiring harness connecting to the DEF tank header for shorts or open circuits

4. 4

   Inspect the tank for crystallized DEF or contamination (such as diesel fuel) which can ruin the sensor and dosing unit

1. 1

   Refill the Tank

   Fill the DEF tank with high-quality, uncontaminated Diesel Exhaust Fluid (32.5% urea). Cycle the key and use a diagnostic tool (like John Deere Service ADVISOR) to see if the code clears.

2. 2

   Access the Header

   If the sensor has failed, you must replace the DEF Tank Header Assembly (the level sensor is not serviced separately from the header).

3. 3

   Drain the Tank

   Drain the remaining DEF from the tank into a clean container to prevent spills.

4. 4

   Disconnect Lines

   Disconnect the electrical connector and the DEF supply/return fluid lines from the top of the DEF tank header.

5. 5

   Remove the Header

   Remove the mounting hardware or retaining ring securing the header to the tank. Carefully pull the old header assembly out of the tank.

6. 6

   Install New Part

   Insert the new DEF Tank Header Assembly, ensuring you use a new flat gasket to prevent leaks.

7. 7

   Reassemble

   Secure the retaining ring/hardware, and reconnect the fluid lines and electrical connector.

8. 8

   Clear Codes

   Refill the DEF tank, turn the key to the ON position, and use a diagnostic tool to clear the 001761.01 fault code and reset the SCR inducement derate.