Case IH 19390 – Engine Control Module (ECM / ECU): Timeout of CAN-Receive-Frame Torque / Speed control from ACC to ECM through TSC1_ACCE message

The Engine Control Module (ECM) has timed out while waiting to receive the TSC1_ACCE (Torque/Speed Control 1) message frame from the ACC (Adaptive Cruise Control / Advanced Cab Controller) module, indicating a CAN bus communication failure.

• Tier 4b
• Puma
• Maxxum
• Optum
• Steiger
• N-Series Loaders
• Tier 4B excavators

1. 1

   Use a diagnostic tool (like CNH Electronic Service Tool - EST) to check the CAN bus load for a flooded bus

2. 2

   Check the CAN bus wiring harness (CAN High and CAN Low) between the ACC module and the Engine ECM for open circuits, short circuits to ground, or short circuits to power

3. 3

   With the battery disconnected, measure the resistance across the CAN High and CAN Low pins at the diagnostic port (should read approximately 60 ohms)

4. 4

   Inspect the connectors at both the ECM and the ACC module for loose, pushed-back, or corroded pins

5. 5

   Verify the battery voltage and ground connections to both the ECM and the ACC module

1. 1

   Power Down

   Turn the key switch to the OFF position and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Inspect Connectors

   Locate the Engine ECM and the ACC module. Disconnect their main harness connectors. Inspect the pins for moisture, corrosion, or damage. Clean with electrical contact cleaner if necessary.

3. 3

   Continuity Testing

   Using a digital multimeter, perform a continuity test on the CAN High and CAN Low wires directly between the ACC connector and the ECM connector.

4. 4

   Short-to-Ground Testing

   Test both CAN wires for continuity to a known good chassis ground. If there is continuity, locate and repair the short in the harness.

5. 5

   Repair Wiring

   Repair or replace any damaged wiring in the CAN harness. If a connector pin is damaged or lacks tension, replace the pin using an OEM pigtail/terminal repair kit.

6. 6

   Reassemble and Clear Codes

   Reconnect all modules and the battery. Turn the key ON and use the CNH EST diagnostic tool to clear the fault codes.

7. 7

   Software Update / Module Replacement

   Start the engine and verify if the code returns. If the wiring is perfectly intact and the terminating resistance is correct, the ACC module or the ECM may require a software re-flash (to correct message broadcast intervals) or hardware replacement.