Case IH 3184 (DTC 94CB) - ECU – Engine Control Unit (ECU) / ECU A-095: CAN communication failure between vehicle controller and ECU controller - TSC1_VR message (Engine brake)

The Engine Control Unit (ECU) has experienced a passive timeout and is no longer receiving the expected Torque Speed Control (TSC1_VR) CAN bus messages from the main vehicle controller regarding the engine brake.

• MAXXUM T4E
• Puma Series Tractors
• Magnum Series Tractors (MX210, MX230, MX255, MX285)
• 240 Series Axial-Flow Combines
• Sugar Cane Harvesters (A8000 / A8800 / A9900 series)

1. 1

   Verify that the machine's battery has not been connected to an external power supply (such as a jump box or external charger). Disconnect if present and retest.

2. 2

   Use the Electronic Service Tool (EST) to check for other active vehicle CAN faults (such as CAN A Bus off failures). These must be resolved first as they can cause the TSC1_VR message to drop.

3. 3

   Disconnect the vehicle harness from the ECU A-095 at connector X-911 and check for proper supply voltage on the harness side with the ignition ON.

4. 4

   Visually inspect the harnesses and connectors between the vehicle controller and the ECU for damaged, bent, or pushed-back pins, corroded terminals, or broken wires.

1. 1

   Resolve Network Issues

   If diagnostic checks reveal broader CAN bus communication errors, troubleshoot the CAN Node A Bus wiring first.

2. 2

   Harness Flex Test

   Flex the involved wiring harnesses while the machine is operating and observe the monitor. This will help reveal intermittent breaks or shorts in the CAN wiring.

3. 3

   Repair Wiring

   If any physical damage, corrosion, or poor pin fitment is found in the CAN bus wiring or at connector X-911, repair or replace the affected connector/harness.

4. 4

   Software Verification

   If the wiring is intact and the fault has not been resolved, check that the ECU A-095 has the appropriate software installed. Re-flash (reinstall) the ECU software using the EST if necessary.

5. 5

   Module Replacement

   If the ECU A-095 cannot be re-flashed, or if the internal powerstage/SPI bus communication has failed internally despite good wiring and voltage, the ECU A-095 must be replaced.