Case IH 3420 – ENGINE: CAN Bus Communication - CAN Bus Received Frames: DFC of Auxiliary Engine Shutdown Switch Message

This is an informational fault indicating that the engine was shut down because the Engine Control Unit (ECU) received a shutdown command over the CAN bus from an external source, specifically the Auxiliary Engine Shutdown Switch. There is typically no mechanical failure within the engine itself.

• skid steer
• SR220
• SR250
• SV250
• SV300
• L223
• L225
• L230
• TR320
• TV380
• C232
• C238
• 21F
• 121F
• 221F
• 321F
• Steiger
• Magnum
• Farmall

1. 1

   Verify if the operator intentionally pressed the emergency stop or auxiliary shutdown switch. If so, simply reset the switch.

2. 2

   Inspect the auxiliary switch circuit if the engine shut down unexpectedly.

3. 3

   Visually inspect the relevant harnesses and connectors leading to the auxiliary shutdown switch for damage, chafing, or bent/dislocated pins that could cause a false shutdown signal.

1. 1

   Resolve the Root Cause

   Reset or replace the tripped/faulty auxiliary engine shutdown switch.

2. 2

   Connect Diagnostic Tool

   Turn the vehicle key to the ON position with the Engine OFF. Connect the CNH Electronic Service Tool (EST).

3. 3

   Clear Codes

   Attempt to clear the fault code using the EST. If the code clears and does not return upon startup, return the machine to service.

4. 4

   ECU Re-initialization

   If the code is stuck active despite the switch functioning properly, use the EST service tool to re-initialize the ECU and load the appropriate data-set for the engine type. (Note: A call to CNH TSS may be required to get an authorization code for the ECU initialization download).

5. 5

   ECU Replacement

   If the fault code still does not clear after harness verification and ECU re-initialization, the Engine ECU may have suffered an internal logic failure and must be replaced.