Case IH 19887 – Engine ECU (Diesel Engine) or Vehicle Control Module (VCM) / Heater Control Unit (HCU): Signal error for cardan speed over CAN

The vehicle speed sensor (or cardan speed sensor) connected via the CAN bus is broadcasting an invalid signal, typically due to a defective speed measuring device, an incorrect speed evaluation, or a disturbed CAN communication signal.

• Tier 4b
• Case N-series TLBs
• Case IH MX/TG series
• Case IH Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Luxxum
• Axial-Flow models

1. 1

   Visually inspect the vehicle speed sensor (cardan speed sensor) for physical defects or damage

2. 2

   Inspect the wiring harness for open circuits, short circuits to the battery, or short circuits to ground

3. 3

   Check the CAN bus communication lines for timeouts or disturbed signals

4. 4

   Note if the error only occurs during cold starts (can be triggered by high torque requests when hydraulic/transmission oil is cold and non-liquid)

1. 1

   Inspect and clean connectors

   Inspect and clean the electrical connectors associated with the vehicle speed sensor / cardan speed sensor.

2. 2

   Repair wiring

   Repair any broken wires or short circuits found in the sensor's harness.

3. 3

   Verify voltage

   Verify that the voltage supply to the sensor is within the correct physical signal range.

4. 4

   Replace sensor

   If the wiring and voltage are correct but the CAN signal remains invalid, replace the defective vehicle speed sensor.

5. 5

   Check and replace ECU

   If the sensor has been replaced and the wiring is verified as good, check the ECU for internal faults. Replace the ECU if it is determined to be the root cause.