New Holland ENG 3185 – Engine Control Unit (ECU): Timeout of CAN message TF

This code indicates a Controller Area Network (CAN) bus communication failure. Specifically, the engine controller did not receive the "TF" CAN message from the main communication system (usually the Transmission Control Unit or Vehicle Control Module) within the allotted time limit.

• T7 Series (T7.175, T7.220, T7.235, T7.245, T7.250, T7.260, T7.270)
• T8 Series (T8.325, T8.330)
• CR/CX Series (CR9040, CR9060, CR9070, CR9080, CX8080, CX8090)
• FR Series (FR450 - FR850)
• Puma Series
• Wheel Loaders (721F, 821F, 921F)
• Crawler Dozers

1. 1

   Check for multiple CAN codes (e.g., 3178, 3179, 3180, 3182) which indicate the entire CAN bus circuit is compromised rather than just the TF message line

2. 2

   Perform a visual inspection of the wiring harness between the Engine ECU and the Transmission/Vehicle controller for chafed wires, loose connectors, or bent pins

3. 3

   Test the CAN network terminating resistors by measuring resistance between the CAN High (yellow) and CAN Low (green) wires with the machine off and battery disconnected (should read exactly 60 ohms)

4. 4

   If the resistance reading is 120 ohms, check for a failed terminating resistor or a break in the wiring harness leading to it

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Inspect Connectors

   Locate the Engine ECU and the Transmission Control Unit (TCU). Disconnect the harness connectors and inspect for corrosion, bent pins, or pushed-back terminals. Clean the contacts with electrical contact cleaner.

3. 3

   Verify the CAN Circuit

   Perform the 60-ohm resistance test on the CAN bus.

4. 4

   Replace Terminating Resistor

   If your resistance test yielded 120 ohms, locate the terminating resistors (often found near the ECU or at the physical ends of the harness). Unplug them and test them individually. Replace any resistor that does not read 120 ohms.

5. 5

   Repair Wiring

   If the resistors are good, perform a continuity test on the CAN High and CAN Low wires between the ECU and TCU. Repair any open circuits or shorts to ground/power.

6. 6

   Clear Codes

   Reconnect all modules and the battery. Use the CNH Electronic Service Tool (EST) to clear the fault codes from the modules.

7. 7

   Retest

   Run the machine. If the wiring and resistors are perfect but the code returns and remains active, the ECU or TCU may have suffered an internal failure requiring replacement and reprogramming.