Case IH 17571 (F-519050-09) - ECU – Engine Control Module (ECM): Timeout Error of CAN-Receive-Frame A1DEFI from DEF/Adblue quality sensor

The engine's control system has lost communication with the DEF (Diesel Exhaust Fluid) quality sensor over the Controller Area Network (CAN bus). The controller expects to receive regular data frames (designated as "A1DEFI") reporting the DEF fluid quality and temperature. When this message is not received within the expected time window, a timeout error is triggered.

• VESTRUM CVX
• Case IH Tier 4 Final and Stage V agricultural equipment
• Case IH Farmall series (40, 45, 50 CVT models, and 115U Efficient Power)
• Various Case IH tractors utilizing FPT / Cummins engines with MTA CCM & APH Stage V MR on-board diagnostics

1. 1

   Visually inspect the DEF tank and DEF quality sensor (usually integrated into the DEF header unit) for physical damage.

2. 2

   Disconnect the sensor and inspect the connector pins and circuit boards for corrosion caused by vented ammonia gas.

3. 3

   Check the CAN cable connecting the sensor interface to the network for chafed insulation, cuts, broken wires, or short circuits, and verify correct CAN bus termination resistance.

4. 4

   Verify the tractor's battery and alternator voltage is between 13.8V and 14.4V while running, as low voltage can cause CAN communication drops.

5. 5

   Check for related CAN timeout codes (e.g., SPN 639) which would indicate a damaged main CAN bus backbone rather than an isolated DEF sensor issue.

1. 1

   Disconnect Power

   Disconnect the battery ground wire to prevent damage to wires and sensors caused by an accidental short circuit during repair.

2. 2

   Access the Sensor

   Clean the area around the top of the DEF tank to prevent dirt from falling into the tank.

3. 3

   Remove the Sensor/Header

   Disconnect the electrical harness from the DEF quality sensor. Depending on the specific tank architecture, remove the mounting bolts or retaining ring holding the DEF header/sensor assembly to the tank.

4. 4

   Install the New Part

   Insert the new DEF quality sensor assembly into the tank, ensuring the sealing gasket or O-ring is properly seated to prevent ammonia gas leaks.

5. 5

   Reconnect

   Secure the mounting hardware and plug in the electrical connector. Reconnect the battery ground wire.

6. 6

   Clear Codes

   Turn the key on and use a dealer diagnostic service tool to clear the fault codes. Verify that the ECM is now successfully receiving the A1DEFI CAN frames from the new sensor.