Case IH 19351 – Engine Control Module (ECM / EDC) or Vehicle Control Module (VCM): Timeout Error of CAN-Transmit-Frame ISCS

CAN bus communication error indicating that the control module expected to receive or transmit the ISCS (Operator Primary Intermediate Speed) data frame over the CAN bus, but the message timed out. This usually points to a physical wiring issue, a failed terminating resistor, or a faulty module.

• Tier 4b
• Case IH Steiger series
• Case IH Magnum series
• Case IH Puma series
• Case N-Series Loaders
• T7 Series

1. 1

   Check for accompanying CAN timeout codes (e.g., 19350, 19353, 19354) to determine if the entire CAN bus is down rather than just the ISCS circuit.

2. 2

   Perform a CAN Bus Resistance Test with key OFF and battery disconnected. Measure resistance between CAN High and CAN Low (healthy is 60 ohms; 120 ohms indicates an open circuit or missing resistor; near 0 ohms indicates a short).

3. 3

   Perform a CAN Bus Voltage Test with key ON and modules connected. CAN High should read 2.5V to 2.7V, and CAN Low should read 2.3V to 2.5V (0V or 12V indicates a short to ground or power).

4. 4

   Isolate the network by disconnecting modules one by one to see when resistance returns to normal (60 ohms) to isolate the faulty branch.

5. 5

   Physically inspect the wiring harness between the ECM/VCM and the cab controls for chafing, moisture intrusion, or loose connector pins.

1. 1

   Disconnect Power

   Disconnect the negative battery cable before performing any physical repairs to the wiring harness.

2. 2

   Repair Harness/Connectors

   If the diagnostic checks revealed a short or open circuit in the wiring between the ECM and the ISCS input, repair the broken wire or replace the corroded connector pins.

3. 3

   Replace Terminating Resistor

   If the resistance test yielded 120 ohms and the wiring is intact, locate and replace the faulty 120-ohm CAN terminating resistor on that specific bus segment.

4. 4

   Replace Faulty Module

   If the wiring is perfectly intact, resistance is 60 ohms, and voltages are correct, the fault lies internally within either the ISCS switch/module or the ECM itself. Replace the faulty component.

5. 5

   Re-test and Calibrate

   Reconnect the battery, clear the stored fault codes using a diagnostic tool, and cycle the machine power. Test the intermediate speed control to ensure the CAN frame is successfully transmitting.