Case IH 3652 – Engine Control Unit (ECU) / EDC: Primary Vehicle CAN Bus Failure - Bus Off On CAN Node A

This code indicates that the control module has lost communication on the primary vehicle CAN (Controller Area Network) bus. The "Bus Off" state means the CAN controller detected an excessive number of transmission or reception errors and has intentionally disconnected itself from the network to prevent disrupting communication between other modules.

• Farmall
• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Backhoe Loaders (580 series, 590SN)
• Tractors (Farmall series)
• Rough terrain forklifts (586H)

1. 1

   Verify battery voltage and alternator output, as low or incorrect battery voltage can cause the ECU to drop CAN communication.

2. 2

   Visually inspect the engine wiring harness connecting the Engine ECU to the main vehicle CAN bus for chafed wires, opens, shorts to ground, or shorts to power on the CAN High and CAN Low lines.

3. 3

   Inspect the pins at the Engine ECU and inline harness connectors for corrosion, moisture, or bent pins.

4. 4

   With the battery disconnected, measure the resistance across the CAN High and CAN Low pins to test terminating resistors (a healthy CAN bus should read approximately 60 ohms).

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical spikes during repair.

2. 2

   Repair Wiring

   If the diagnostic checks revealed damaged wiring in the F5C engine harness, splice and repair the affected CAN lines using OEM-approved heat-shrink connectors, or replace the engine harness section entirely.

3. 3

   Clean Connections

   If corrosion is found at the ECU connector, clean the pins with electrical contact cleaner and apply dielectric grease before reconnecting.

4. 4

   Replace the ECU

   If the wiring harness, power supply, and terminating resistors all test perfectly, the CAN transceiver inside the Engine ECU has likely failed. Remove the faulty Bosch EDC/ECU and install a replacement.

5. 5

   Reprogramming

   If a new Engine ECU is installed, it will need to be flashed/programmed by a Case IH dealer with the correct software trim level for your specific machine.

6. 6

   Clear Codes

   Reconnect the battery, cycle the key, and use a diagnostic tool to clear the inactive 3652 fault code.