Case IH 19845 – Engine Control Unit (ECU): CAN timeout error for TSC1 AD management (Torque request to Retarder - ECU makes retarder function)

This code indicates a communication failure on the Controller Area Network (CAN) bus. Specifically, the Engine Control Unit (ECU) has timed out while waiting to receive the TSC1 (Torque Speed Control 1) message from the AD (Advanced Drivetrain / Autonomous Driving) management or retarder control module. This means the engine is not receiving the necessary torque reduction or retarder requests over the network.

• Tier 4b
• Case CE N-Series Tractor Loader Backhoes (TLBs)
• 580N
• 580SN
• 590SN
• Case IH agricultural tractors with Tier 4 Final engines

1. 1

   Perform a CAN Bus Resistance Test: With the machine turned off and battery disconnected, measure resistance between CAN_H and CAN_L pins (should read exactly 60 ohms).

2. 2

   Perform a CAN Bus Voltage Test: Reconnect the battery and turn the key ON (engine off). Measure CAN_H (2.5V to 3.5V) and CAN_L (1.5V to 2.5V) to ground.

3. 3

   Visually inspect the wiring harness between the Engine ECU and the transmission/retarder controller for chafing, pinched wires, or heat damage.

4. 4

   Disconnect the ECU and retarder module connectors and check for pushed-out pins, corrosion, or moisture intrusion.

5. 5

   Connect the Case IH Customer EST to check for other active CAN communication codes (e.g., 19841, 19842, 19843) which might indicate a broader network failure.

1. 1

   Prepare the Machine

   Park the machine on a flat, level surface, chock the wheels, lower any attachments to the ground, turn off the engine, and remove the ignition key. Let the machine cool down.

2. 2

   Isolate Power

   Disconnect the negative battery cable to prevent electrical shorts during harness repair.

3. 3

   Clean and Reseat Connectors

   If the diagnostic checks revealed corrosion or loose pins at the ECU or transmission controller, apply a high-quality electrical contact cleaner to the pins. Carefully reshape any bent pins and apply dielectric grease to the connector seals.

4. 4

   Repair the Wiring Harness

   If the resistance test failed (e.g., open circuit or short to ground), trace the CAN_H and CAN_L wires along the chassis. Cut out any damaged sections of the twisted-pair wiring and solder in replacement wires, ensuring you maintain the twisted-pair configuration (approximately one twist per inch) to prevent electromagnetic interference. Seal the repair with dual-wall adhesive heat shrink.

5. 5

   Replace Terminating Resistor (if applicable)

   If the bus resistance measured 120 ohms and the wiring is intact, locate and replace the faulty 120-ohm CAN terminating resistor.

6. 6

   Reassemble and Test

   Reconnect all modules and the negative battery cable.

7. 7

   Clear Codes

   Turn the ignition ON and use the Case IH EST to clear the 19845 fault code. Start the engine and verify that the code does not return and that the retarder/transmission functions operate normally.