Case IH 19851 – Engine Control Unit (ECU) or Vehicle Control Module (VCM): CAN timeout error for TSC1 for active cruise control management torque and/or speed request to ECU

The TSC1 (Torque/Speed Control 1) is a standard SAE J1939 CAN bus message used by vehicle systems to request specific engine speeds or torque limits. This fault indicates that the Engine Control Unit (ECU) has lost communication with the active cruise control management system. The expected TSC1 CAN message has "timed out" (stopped arriving within the expected millisecond timeframe), causing the system to disable cruise control and potentially limit engine performance for safety.

• Tier 4b
• Case N-Series Tractor Loader Backhoes (TLBs)
• Maxxum tractors
• Tier 3 engines
• Tier 4a engines
• Tier 4 Final engines

1. 1

   Check for accompanying CAN timeout codes (e.g., EEC1, EEC2, or other TSC1 codes) to determine if the entire CAN bus backbone is compromised

2. 2

   Perform a CAN bus resistance test at the diagnostic port with the machine off and battery disconnected (should read approximately 60 ohms)

3. 3

   Inspect the wiring harness between the VCM, the cruise control input switches, and the ECU for chafed wires, pinched harnesses, or moisture ingress in the connectors

4. 4

   Verify via the CNH Electronic Service Tool (EST) that the ECU is properly configured to accept J1939 TSC1 throttle control and that the source address for the cruise control module hasn't been corrupted

1. 1

   Disconnect Power

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

2. 2

   Inspect Connectors

   Disconnect the main harness connectors at the VCM and the ECU. Inspect the pins for corrosion, pushed-back pins, or spread terminals. Clean with electrical contact cleaner if necessary.

3. 3

   Perform Continuity Testing

   Using a multimeter, perform a pin-to-pin continuity test on the CAN High and CAN Low wires between the VCM and the ECU.

4. 4

   Repair Wiring

   If an open circuit, short to ground, or short to voltage is found in the CAN lines, repair the damaged section of the harness using OEM-approved twisted-pair CAN wire and heat-shrink connectors.

5. 5

   Check Terminating Resistors

   If the CAN resistance test (from the diagnostic steps) yielded 120 ohms or higher, locate and replace the failed CAN terminating resistor.

6. 6

   Reprogram/Update

   If the wiring is 100% intact, connect the CNH EST diagnostic tool. Flash the VCM and ECU with the latest software updates, as CAN timeout sensitivities are frequently patched in newer software revisions.

7. 7

   Clear and Test

   Clear the fault codes, start the engine, and test-drive the machine while engaging the active cruise control to verify the TSC1 message is broadcasting properly.