Case IH 19846 – Engine Control Module (ECM): CAN timeout error for TSC1 for active cruise control management (Torque request to Retarder - ECM makes retarder function)

A Controller Area Network (CAN) communication failure indicating the Engine Control Module (ECM) has stopped receiving the expected Torque/Speed Control 1 (TSC1) data messages from the active cruise control or retarder management system within the required timeframe.

• Tier 4b
• Case IH T7 Series
• Case N-Series

1. 1

   Scan for related codes using the CNH Electronic Service Tool (EST) or DATAR Scope to check for other active CAN bus errors. Multiple codes indicate a main CAN bus failure rather than an isolated issue.

2. 2

   Inspect the CAN-High and CAN-Low wiring between the ECM and the Vehicle Control Module (VCM) or retarder control unit for chafing, breaks, or shorts to ground/power.

3. 3

   With the battery disconnected, measure the resistance across the CAN bus pins at the diagnostic connector. It should read approximately 60 ohms. A reading of 120 ohms indicates a failed or missing terminating resistor.

4. 4

   Disconnect the ECM and VCM harnesses and inspect the pins for corrosion, moisture ingress, or pushed-out pins.

5. 5

   Verify that the ECM parameters for the retarder and active cruise control (e.g., Automatic Cruise Resume) are correctly enabled and configured in the software.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery terminal before servicing the ECM or wiring harness.

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks revealed damaged wiring or corroded connector pins on the CAN bus circuit, repair the affected wire sections or replace the damaged connector pigtails. Clean any mild corrosion with electrical contact cleaner and apply dielectric grease.

3. 3

   Replace Terminating Resistor

   If the CAN bus resistance check failed, locate and replace the faulty CAN bus terminating resistor.

4. 4

   Software Update

   If the wiring and connectors are in perfect condition, connect the CNH EST diagnostic tool. Check for available software updates for the ECM and VCM, as CAN timeout glitches are sometimes resolved via OEM software patches. Flash the modules to the latest software version.

5. 5

   Module Replacement

   If the wiring is intact, software is up to date, and the code remains active, the fault lies within the internal CAN transceiver of either the ECM or the module sending the TSC1 message. Replace the faulty control module.

6. 6

   Clear and Test

   Reconnect the battery, clear the inactive fault codes using the diagnostic tool, and test-drive the machine. Engage the active cruise control and retarder to verify the repair.