Case IH 3875 – Engine Control Unit (ECU): Timeout of CAN message TSC1-DR passive

CAN bus communication error where the Engine Control Unit (ECU) has lost communication or timed out while waiting for the 'TSC1-DR' (Torque/Speed Control 1, Driveline or Drive Retarder) message in a passive state.

• Magnum 180
• Magnum 200
• Magnum 220
• Magnum 235
• Magnum 240
• Magnum 340
• Magnum 380
• Steiger 370
• Steiger 420
• Steiger 500
• Steiger 620
• Puma
• Maxxum
• Farmall
• 521F
• 621F
• 721F
• 1021F
• 1150K
• 1650L
• T8
• T9

1. 1

   Check for accompanying CAN bus codes (e.g., Bus-off states, missing messages from other modules) which would indicate a global CAN failure rather than a specific module failure.

2. 2

   Inspect the CAN bus wiring harness and connectors between the Engine ECU and the Transmission/Vehicle Controller for chafing, cuts, corrosion, or pushed-out pins.

3. 3

   Disconnect the battery and measure the resistance between CAN High and CAN Low at the diagnostic port or ECU connector (should read approximately 60 ohms).

4. 4

   With the key on, check the voltage on the CAN lines. CAN High should be around 2.5V to 2.7V, and CAN Low should be around 2.3V to 2.5V.

5. 5

   Locate and test the active/passive CAN bus terminating resistors to ensure they have not failed or burned out.

1. 1

   Disconnect Power

   Disconnect the negative battery cable before performing any electrical repairs.

2. 2

   Repair Wiring

   If the visual inspection or continuity tests reveal a short to ground, short to battery, or an open circuit on the CAN lines, repair the damaged section of the wiring harness or replace the affected pigtail/connector.

3. 3

   Replace Terminating Resistor

   If the CAN bus resistance is 120 ohms (indicating one missing resistor) or out of spec, locate the faulty terminating resistor (often located under the cab, near the air filter, or behind the controllers) and replace it.

4. 4

   Software Update

   If the wiring and resistors are perfectly intact, the issue may be a software glitch. Connect the Case IH Electronic Service Tool (EST) to check for ECU/TCU software updates.

5. 5

   Module Replacement

   If all wiring, resistors, and software are verified good, the Engine ECU or the transmitting module (Vehicle Controller) may have an internal hardware failure on its CAN transceiver and will need to be replaced and reprogrammed.