Case IH 19397 – Engine Control Module (ECM): CAN timeout error - TSC1TE message (Limp home status)

The Engine Control Module (ECM) expects to receive continuous torque and speed limit requests from the Transmission Control Unit (TCU) to coordinate shifting and engine load. This code triggers when the ECM fails to receive the TSC1TE message over the CAN bus for a specified timeout period (typically >40 milliseconds). Because the engine no longer knows what the transmission is doing, it defaults to a "Limp Home" status (power and speed derate) to protect the powertrain from damage.

• Tier 4b
• Tier 4B (and newer Stage IV/V) Case IH tractors
• Case IH Puma series
• Case IH Optum series
• Case IH Magnum series
• Case IH Steiger series

1. 1

   Check for companion codes using a diagnostic tool (like CNH EST) to determine if multiple modules are offline or if the issue is isolated to the TCU.

2. 2

   Verify the Transmission Control Unit (TCU) is receiving proper battery voltage and has a clean ground.

3. 3

   Perform a CAN bus resistance test at the diagnostic port with the negative battery terminal disconnected (should read approximately 60 ohms; 120 ohms indicates a broken wire/missing resistor, 0 ohms indicates a short).

4. 4

   Visually inspect the wiring harness between the Transmission Controller and the Engine ECU for chafing, rodent damage, or melted insulation.

1. 1

   Disconnect Power

   Always disconnect the chassis bonding cable from the battery's negative terminal before servicing CAN bus components.

2. 2

   Inspect Connectors

   Locate the main harness connectors at both the Engine ECU and the Transmission TCU. Disconnect them and inspect the pins for moisture, corrosion, or fretting (micro-wear). Clean with electrical contact cleaner and apply dielectric grease.

3. 3

   Test Continuity

   Using a multimeter, perform a continuity test on the CAN High and CAN Low wires specifically between the TCU and the ECM.

4. 4

   Repair Wiring (If Applicable)

   If a break or short is found, repair the wiring. Crucial: CAN bus wires are a twisted pair. If splicing in a repair, you must maintain the twist rate (typically 1 twist per inch) to prevent electromagnetic interference.

5. 5

   Module Replacement (If Applicable)

   If the wiring is perfectly intact, terminating resistors are good, and the TCU has power but still fails to communicate the TSC1TE message, the CAN transceiver inside the Transmission Controller has likely failed. Replace the TCU.

6. 6

   Clear and Test

   Reconnect the battery, clear the fault codes using the diagnostic tool, and perform a test drive to ensure the Limp Home status is deactivated and the ECM is receiving transmission data.