Massey Ferguson U 2854 - U 2858 – Engine Control Unit (ECU) and SCR (Selective Catalytic Reduction) / Dosing Control Unit (DCU): CAN receiver error

CAN Rx (Receive) Frames failing to broadcast valid data over the Controller Area Network (CAN bus). The system is receiving out-of-range data, overridden messages, or experiencing communication timeouts from environmental and emissions sensors.

• Massey Ferguson 8600 Series (8650, 8660, 8670, 8680, 8690)
• Massey Ferguson 5600 Series
• Massey Ferguson 6600 Series
• Massey Ferguson 7600 Series
• Massey Ferguson 8700 Series

1. 1

   Read the specific Failure Mode Identifier (FMI) using a diagnostic tool (FMI 19 indicates a timeout or dead sensor, FMI 2 indicates a range error or failing sensor).

2. 2

   Inspect the CAN bus wiring harness and connectors leading to the NOx sensor and Ambient Air Temperature/Barometric pressure sensor for chafing, corrosion, or moisture.

3. 3

   Test CAN network integrity by disconnecting the battery and measuring resistance across CAN High and CAN Low pins (should read approximately 60 ohms).

4. 4

   Verify that the affected sensors are receiving proper supply voltage and have a solid ground connection.

1. 1

   Disconnect power

   Disconnect the tractor battery before servicing the electrical or emissions system to prevent short circuits.

2. 2

   Repair wiring

   If diagnostic checks reveal damaged wiring or a faulty connector on the CAN bus network, repair the damaged section or replace the connector pigtail.

3. 3

   Replace faulty sensor

   If wiring and CAN resistance are intact, replace the failing sensor. For the NOx sensor (U 2855/U 2856), unthread from the exhaust bung, clean threads, and install the new sensor. For the Ambient Air Temp sensor (U 2854), unplug the harness, unclip from the bracket, and snap the new one into place.

4. 4

   Clear codes

   Reconnect the battery, connect a diagnostic tool, and clear the inactive U 2854 - U 2858 fault codes.

5. 5

   Verify repair

   Start the tractor and monitor live data for the SCR and Engine systems to ensure CAN Rx frames are broadcasting correctly and codes do not return.