Case IH 19889 – Vehicle Controller (VCU / Transmission Controller) / Engine Control Unit (ECU) / Instrument Cluster Display Unit (ICDU): Vehicle speed CAN message not received

The control network (CAN bus) is failing to transmit or receive the electronic message that broadcasts the machine's current travel speed. This can result in engine power loss, emergency re-start modes (limiting operation to 30 seconds before dropping to low idle), or disabled automatic functions.

• Tier 4b
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Magnum series tractors
• Maxxum series tractors
• Puma series tractors
• N-Series Loaders and Backhoes (e.g., 580N)

1. 1

   Check for accompanying CAN faults (such as DTC 931B or 951B). If multiple CAN codes are present, the issue is likely a damaged CAN harness rather than a faulty speed sensor.

2. 2

   Visually inspect the CAN bus wiring harness between the transmission/vehicle controller and the ECU for chafing, pinched wires, or disconnected plugs.

3. 3

   Verify the CAN bus terminating resistors are intact (typically reading 120 ohms across the CAN-High and CAN-Low pins).

4. 4

   Inspect the vehicle/transmission speed sensor pigtail connector for corrosion, moisture ingress, or physical damage from field debris.

5. 5

   Verify that the speed sensor is receiving the correct reference voltage (typically 5V or 11V depending on the specific machine's architecture).

1. 1

   Power Down

   Turn off the machine and engage the master battery disconnect switch to protect the CAN modules during repair.

2. 2

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a broken CAN wire or corroded connector, splice the wire using OEM-approved weather-sealed connectors or replace the damaged harness section.

3. 3

   Replace the Speed Sensor (If Applicable)

   If the CAN bus is healthy but the sensor is dead, disconnect the sensor harness. Unthread the faulty speed sensor from the transmission housing or wheel hub.

4. 4

   Install New Sensor

   Thread the new OEM speed sensor into the housing. Connect the wiring harness, ensuring the weather seal clicks firmly into place.

5. 5

   Clear Codes and Test

   Turn the battery disconnect back on. Use the diagnostic scan tool (or the in-cab ICDU diagnostic screen) to clear the inactive 19889 fault code. Test drive the machine to ensure the speedometer registers correctly and the code does not return.