Massey Ferguson U 2860 - U 2871 – Engine Control Module (ECM / EEM3) and Dosing Control Unit (DCU): CAN Frame Error / CAN Frame Time Date Error

Communication failure on the Controller Area Network (CAN) bus where expected data messages are either timing out, being overridden, or reporting out-of-range values.

• Massey Ferguson 8600 Series
• Massey Ferguson 7600 Series
• Massey Ferguson 5700 SL Series

1. 1

   Use a diagnostic scanner (like AGCO EDT or Jaltest) to identify which specific module (e.g., DCU, EGR valve, or instrument panel) has dropped off the network

2. 2

   With the key off and battery disconnected, measure the resistance across the CAN bus (a healthy CAN bus should read approximately 60 ohms)

3. 3

   Verify battery voltage and check the main relays (low voltage or a failing main relay can cause modules to power down, resulting in CAN timeout errors)

4. 4

   Visually inspect the wiring harness along the entire bus path between the EEM3 controller and the instrument panel/DCU for rub points or disconnected plugs

5. 5

   Disconnect modules one by one to isolate the fault and see if a specific shorted module is pulling down the entire CAN network

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Harness

   Locate the main engine-to-cab CAN wiring harness, focusing on the connections at the EEM3 (Engine ECU) and the DCU/SCR module.

3. 3

   Inspect and Clean Connectors

   Disconnect the harness plugs. Look for pushed-back pins, corrosion, or moisture intrusion. Clean the contacts with electrical contact cleaner and ensure the pins have proper tension.

4. 4

   Repair Wiring

   If you find chafed wires (a common issue where the harness routes near the engine block or transmission housing), cut out the damaged section, solder in new wire, and seal it with heat-shrink tubing.

5. 5

   Replace Faulty Components

   If the wiring tests perfectly but a specific module (like the NOx sensor or DCU) is internally shorted and corrupting the CAN signal, replace the offending module.

6. 6

   Reassemble and Clear Codes

   Reconnect all modules and the battery. Turn the key to the ON position. Connect your AGCO EDT or compatible diagnostic tool and clear the inactive fault codes.

7. 7

   Test Run

   Start the tractor and monitor the live CAN voltage and dashboard to ensure the communication is restored and the codes do not return.