Case IH 9154 – UCM (Universal Control Module): Timeout of CAN Message TSC1

The control module is not receiving the expected TSC1 (Torque/Speed Control 1) messages from the engine controller or vehicle controller within the required timeframe, typically caused by a physical wiring issue on the CAN Data Link circuit, outdated software, or a failing module.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• tractors
• combines

1. 1

   Check for multiple active CAN bus fault codes using the Electronic Service Tool (EST) to determine if the issue is systemic (3+ codes) or localized (1-2 codes).

2. 2

   Visually inspect all CAN bus wires and connectors between the UCM and Engine ECU for chafing, corrosion, abrasion, or loose attachments.

3. 3

   Verify that all modules on the CAN bus have the latest software versions installed.

1. 1

   Power Down and Isolate

   Turn off the machine and disconnect the battery to prevent electrical shorts during testing.

2. 2

   Test CAN Bus Resistance

   Locate the CAN bus diagnostic port or back-probe the UCM connector. Measure the resistance across the CAN High and CAN Low pins. A healthy CAN bus should read approximately 60 ohms. If it reads 120 ohms, one of the terminating resistors is faulty or there is an open circuit. If it reads 0 ohms, the CAN lines are shorted together.

3. 3

   Inspect and Clean Connectors

   Disconnect the UCM and Engine ECU harness connectors. Inspect the pins for pushed-back terminals, moisture, or green corrosion. Clean the pins with contact cleaner and apply dielectric grease.

4. 4

   Repair Wiring

   If you find an open or shorted wire in the CAN Data Link circuit during your multimeter continuity tests, repair the damaged section of the harness or replace the affected harness segment.

5. 5

   Update Software

   Reconnect the battery, connect the EST, and flash the UCM and Engine ECU with the latest software datasets.

6. 6

   Module Replacement (Last Resort)

   If the wiring harness tests perfectly, terminating resistors are intact, and software is up to date, the UCM itself has likely suffered an internal failure and must be replaced.

7. 7

   Clear and Verify

   Clear the fault codes using the EST. Start and operate the machine under load to verify the code does not return.