New Holland ENG 1051 – Instrument Cluster (IC) or Universal Control Module (UCM): Loss of CAN Communication with Engine

The machine's main electronic control system has stopped receiving data messages over the Controller Area Network (CAN bus) from the engine's computer.

• L220
• L223
• L230
• C227
• C232
• C238
• SR175
• SR210
• B90B
• B100B
• T4 series
• T5 series

1. 1

   Load-test the battery and ensure voltage does not drop below 10.5V during cranking

2. 2

   Inspect the battery negative, frame grounds, and the engine block ground strap for corrosion or looseness

3. 3

   Verify that the Engine ECU is receiving power by checking all related fuses (such as the ECU-1 fuse)

4. 4

   Inspect the main connector blocks at the Engine ECU and the dashboard/UCM for moisture, pushed-out pins, corrosion, chafing, or rodent damage

5. 5

   Verify the integrity of the CAN bus network by checking the terminating resistors (should provide 120 ohms)

1. 1

   Resolve Power/Ground Issues

   Clean all battery terminals and ground points down to bare metal, reattach, and seal to ensure a perfect connection. Replace the battery if it fails a load test.

2. 2

   Clean Connectors

   Disconnect the Engine ECU harness. Spray the pins and receptacles with a high-quality electrical contact cleaner to remove any moisture or light corrosion. Apply dielectric grease and securely reconnect.

3. 3

   Repair Wiring

   If chafing or rodent damage is found on the CAN bus wiring harness between the engine and the cab, cut out the damaged section and solder/heat-shrink new wiring, or install an OEM harness repair kit.

4. 4

   Clear Codes

   Use the New Holland Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the inactive DTCs from the system.

5. 5

   Replace ECU (Last Resort)

   If the wiring harness has perfect continuity, the terminating resistors are intact, and the ECU is receiving full 12V power and ground but still will not communicate, the Engine ECU has suffered an internal hardware failure and must be replaced and flashed with the correct machine software.