Case IH 3337 – Engine ECU (ENG / EDC): Timeout of CAN Message TSC1-TR (When Active)

The Engine Control Unit (ECU) is failing to receive the "Torque Speed Control 1 - Transmission" (TSC1-TR) message over the J1939 CAN bus network. The transmission or vehicle controller sends this message to command engine speed or torque corrections (e.g., limiting engine speed during certain transmission operations). When the Engine ECU expects this message but does not receive it within the programmed time limit, it logs a timeout error.

• Case IH Magnum Series (235-340 Series 4, 280, 340 Rowtrac)
• Case IH Steiger Series
• Case IH Puma Series

1. 1

   Use the Case IH Electronic Service Tool (EST) to check if other CAN bus modules are dropping offline or if there are general CAN bus errors (e.g., 'Bus off of CAN node A').

2. 2

   Inspect the CAN bus wiring harness between the Engine ECU and the Transmission/Vehicle controller. Look for chafed, cut, or corroded wires, particularly where the harness routes under the cab or near vibration points.

3. 3

   Use a multimeter to check the voltage on the CAN bus lines. CAN High and CAN Low should both rest at approximately 2.4V to 2.5V.

4. 4

   Measure the resistance of the CAN bus network. A healthy CAN bus should read approximately 60 ohms across the network (due to two 120-ohm terminating resistors in parallel). If it reads ~120 ohms, one resistor is missing or a wire is broken. If the reading is incorrect (outside the 108 - 132 Ω range for a single isolated resistor), the wiring or the resistor itself is faulty. Note: Some ECUs contain internal terminating resistors.

1. 1

   Isolate the Fault

   Disconnect the CAN bus connectors at the Engine ECU and the Transmission controller.

2. 2

   Test Continuity

   Pin out the CAN High and CAN Low wires between the two modules to ensure there is no open circuit or short to ground/power.

3. 3

   Repair Wiring

   If a break or high resistance is found in the wiring harness, splice in a CAN bus wiring repair kit (using proper twisted-pair wire and heat-shrink connectors) or replace the damaged harness section.

4. 4

   Check/Replace Terminators

   If the network resistance is incorrect and the wiring is intact, locate the active/passive CAN bus terminating resistors (often located under the cab, near the air filter, or behind the controllers) and replace the faulty terminator.

5. 5

   Module Verification

   If the wiring, voltages, and resistors all test perfectly, the fault lies within a controller. Either the Transmission controller is failing to broadcast the TSC1-TR message, or the Engine ECU's CAN transceiver has failed. Update the software on both modules via the Case IH EST; if the code persists, the faulty module will require replacement.

6. 6

   Clear and Test

   Reconnect all modules, clear the fault codes using the EST, and test-drive the tractor to verify the transmission and engine are communicating properly and the code does not return.