Case IH 3358 – Engine Control Unit (ECU): Engine Sensor CAN Bus Failure

The Engine Control Unit (ECU) has lost communication with the sensors operating on the engine's auxiliary CAN bus network. The ECU is either unable to transmit data out to the sensors, or the sensors are failing to report back to the ECU within the expected timeframe (timeout).

• skid steer
• Case IH Skid Steer Loaders (SSL)
• Case IH Compact Track Loaders (CTL)
• Case IH Steiger Tractors (350 to 620 horsepower models, Quadtrac)
• Case IH Magnum Tractors (180 to 380, 235-340 Series 4)
• Case IH Construction Equipment (580ST, 575N EP Backhoe Loaders, 586H Forklifts)

1. 1

   Harness Visual Inspection: Inspect the engine wiring harness (specifically the routing between the Engine ECU and the engine sensors) for chafing, melting, or rodent damage.

2. 2

   Connector Integrity: Check the main connectors at the Engine ECU and the individual CAN sensors for corrosion, pushed-back pins, or moisture intrusion.

3. 3

   CAN Bus Resistance & Continuity: With the battery disconnected, measure the resistance across the CAN High and CAN Low pins to ensure the terminating resistors are intact. Check for open circuits in the CAN lines.

4. 4

   Short Circuit Testing: Test the CAN High and CAN Low wires for a short to ground or a short to vehicle power.

5. 5

   Sensor Isolation: Because a single shorted sensor can take down the entire CAN bus, unplug the engine sensors one by one to see if communication is restored to the rest of the bus.

1. 1

   Disconnect Power

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

2. 2

   Isolate the Fault

   Based on the diagnostic checks, determine if the fault lies in the wiring harness, a specific sensor, or the ECU itself.

3. 3

   Repair/Replace Wiring (If Applicable)

   If the CAN bus wires are broken or shorted, repair the wiring using OEM-approved splicing methods, or replace the affected engine harness section (e.g., the F5C ECU harness).

4. 4

   Replace Faulty Sensor (If Applicable)

   If unplugging a specific sensor restored the CAN bus, replace that sensor.

5. 5

   Replace the Engine ECU (If Applicable)

   If the wiring harness tests perfectly (no opens, no shorts) and all sensors are functional, the CAN transceiver inside the Engine ECU has likely failed. Remove the faulty ECU and install a replacement.

6. 6

   Reprogramming

   If a new ECU is installed, it must be flashed/programmed with the correct software payload for your specific machine's trim level and engine configuration using the Case IH Electronic Service Tool (EST).

7. 7

   Clear Codes and Test

   Reconnect the battery, clear the 3358 fault code using a diagnostic tool, and run the engine to verify that the CAN Transmit Timeout does not return.