Case IH 19394 – Engine Control Unit (ECU) or Vehicle Control Module (VCM): CAN timeout error - TSC1AE message (Torque/Speed control from ABS/ASR to ECU - Limp home status)

Communication failure on the Controller Area Network (CAN) bus. The engine or vehicle controller has stopped receiving the expected 'TSC1AE' (Torque/Speed Control) data frame from the ABS/ASR module within the required timeframe, forcing the machine into a protective 'Limp Home' mode.

• Tier 4b
• Case N-Series Tractor Loader Backhoes (TLBs)
• Case IH T7 Series (Tier 4B) Tractors
• Case 621G / 721G Wheel Loaders

1. 1

   Disconnect the machine's battery and measure the resistance between the CAN-High and CAN-Low pins at the diagnostic connector (should read approximately 60 ohms).

2. 2

   Reconnect the battery, turn the key ON, and measure the voltage from CAN-High to Ground (should be 2.5V - 3.0V) and CAN-Low to Ground (should be 2.0V - 2.5V).

3. 3

   Verify that the ABS/ASR module is receiving proper operating voltage and has a clean ground.

1. 1

   Isolate the Network

   If the resistance or voltage checks fail, begin disconnecting modules one by one from the CAN bus to see if the voltage returns to normal or the short disappears. This will isolate a faulty module pulling the network down.

2. 2

   Inspect the Harness

   Visually inspect the wiring harness running between the ECU/VCM and the ABS/ASR module. Look for chafing, pinched wires, or melted insulation.

3. 3

   Check Connectors for Moisture

   Disconnect the plugs at the ABS/ASR module and the ECU. Inspect for water intrusion, pushed-back pins, or green corrosion (verdigris). Clean the contacts with electrical contact cleaner and apply dielectric grease.

4. 4

   Repair Wiring / Termination

   If an open or short is found in the wiring, splice and seal the affected CAN lines using proper twisted-pair repair techniques. If a terminating resistor is burnt out, replace it.

5. 5

   Test the ABS/ASR Module

   If the wiring is 100% intact, termination is at 60 ohms, and the ABS/ASR module has verified power and ground but is still not communicating, the ABS/ASR module itself has failed internally and must be replaced.

6. 6

   Clear Codes and Verify

   Reconnect all components, clear the fault codes using a diagnostic scan tool, and test-operate the machine to ensure it successfully exits 'Limp Home' mode.