Massey Ferguson 3532.03 – Engine Control Unit (ECU): DEF Tank Level Sensor Issue (ECU)

SPN 3532 FMI 3 indicates that the DEF tank level sensor's electrical signal voltage is above normal or open circuit. Because the circuit is open or shorted to a high voltage source, the controller cannot determine how much DEF is in the tank, which will eventually trigger an engine power derate.

• 4710
• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4700 Series
• 5600 / 5700 Series
• 5608–5613
• 5710SL–5713SL
• 7600 / 7700 Series
• 7614–7626
• 7714–7726S

1. 1

   Visually inspect the wiring harness leading to the DEF tank header for chafing, rubbing on the frame, or vibration damage.

2. 2

   Disconnect the DEF level sensor and inspect the connector fit, pin tension, and look for dust, moisture, or corrosion inside the pins.

3. 3

   Test the sensor wiring for an open circuit or a short to a high-voltage source, and verify that the sensor is receiving the correct reference voltage and ground from the ECU.

4. 4

   Use a diagnostic scan tool (such as Jaltest or AGCO WinEEM4) to monitor the live DEF level sensor voltage. If the voltage is pegged at maximum (usually 5V) regardless of fluid level, the circuit is open.

1. 1

   Repair Wiring

   If the diagnostic checks reveal a broken wire or corroded connector pin, repair the harness and reconnect the sensor.

2. 2

   Replace Sensor

   If the wiring and ECU outputs test good, the DEF tank level sensor itself has failed internally (open circuit) and must be replaced. On many modern systems, the level sensor is integrated into the DEF Tank Header Assembly.

3. 3

   Clear Codes

   Once the repair is made, you must use a diagnostic tool to save the error log and then erase it.

4. 4

   ECU Reset

   Restart the ECU (cycle the key) after erasing the error log to verify the fault does not return and the warning lamp extinguishes.