Case IH 19847 – Engine Control Module (ECM / ECU): CAN timeout error for TSC1 PTO/Vehicle management torque and/or speed request to ECU

A communication failure on the Controller Area Network (CAN) bus where the Engine Control Unit (ECU) has stopped receiving the expected TSC1 (Torque Speed Control 1) data messages from the Power Take-Off (PTO) or Vehicle Management controller.

• Tier 4b
• Puma
• Magnum
• Optum
• Maxxum
• N-Series Loader Backhoes
• 580N
• 590SN

1. 1

   Check for accompanying CAN timeout codes (e.g., 19848, 19849, 19850) which indicate a global CAN bus failure rather than a specific module issue

2. 2

   Verify battery voltage and inspect chassis grounds, as low voltage or poor grounds can cause modules to drop off the CAN network

3. 3

   Perform a CAN bus resistance test at the diagnostic port with the battery disconnected (a healthy bus should read exactly 60 Ohms)

4. 4

   Visually inspect the wiring harness between the Vehicle Control Module (VCM) / Armrest controller and the Engine ECU for chafing, rodent damage, or corrosion

1. 1

   Power Down

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

2. 2

   Repair Wiring

   If the visual inspection or resistance test revealed a short or open circuit, locate the damaged section of the CAN harness. Splice and solder the broken wires, sealing them with heat-shrink tubing, or replace the affected harness section.

3. 3

   Replace Terminating Resistor

   If the CAN bus tested at 120 Ohms, locate the faulty CAN bus terminating resistor (often located near the ECU, under the cab, or behind the armrest controllers depending on the model) and plug in a replacement.

4. 4

   Clean Connectors

   Disconnect the harnesses at the VCM and ECM. Spray the pins with electrical contact cleaner, apply dielectric grease, and securely reconnect them to ensure there is no pin-drag or moisture intrusion.

5. 5

   Clear Codes and Test

   Reconnect the battery. Use the CNH Electronic Service Tool (EST) to clear the inactive fault codes. Start the tractor and engage the PTO to verify that the ECU is successfully receiving the TSC1 torque/speed requests and that the code does not return.

6. 6

   Module Replacement

   If wiring and resistors are perfect but the code persists, the VCM or ECM may have an internal CAN transceiver failure and will require replacement and dealer reprogramming.