John Deere 191.19 – TIA, UIC, CCU, ECM: Incorrect CAN BUS Message: Transmission Output Speed

The Powertrain (PTA) control software or Transmission Control Unit (TCU) fails to register any transmission output speed from the speed sensor. Because the TCU does not know the speed, it broadcasts a replacement value over the CAN BUS network, triggering this communication fault code in receiving modules.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 9470RT
• 9520RT
• 9570RT

1. 1

   Diagnose TCU Faults First: Use a diagnostic scan tool to read the codes stored directly in the TCU. Look for a specific sensor-level code (e.g., open circuit, short to ground) that takes priority over the CAN communication code.

2. 2

   Inspect Sensor Connections: Check the wiring and connections at the Transmission Output Speed Sensor and the TCU. Look for loose, corroded, or damaged pins.

3. 3

   Verify CAN BUS Communication: Inspect the CAN BUS network for proper termination resistance (typically 60 ohms across CAN High and CAN Low with the battery disconnected) to ensure the network itself isn't dropping packets.

1. 1

   Locate the Sensor

   Identify the Transmission Output Speed Sensor on the transmission housing.

2. 2

   Test the Wiring Harness

   Disconnect the sensor and use a multimeter to check the harness back to the TCU for continuity, shorts to ground, or shorts to battery voltage.

3. 3

   Replace the Sensor

   If the wiring is intact and the TCU is outputting the correct reference voltage, the Transmission Output Speed Sensor has likely failed internally and must be replaced.

4. 4

   Inspect the TCU

   If a new sensor does not resolve the issue, inspect the TCU for internal faults or water ingress. Replace the TCU if it is found to be faulty.

5. 5

   Software Update

   Ensure the TCU and TIA/UIC software are flashed to the latest versions to prevent CAN BUS message compatibility issues.

6. 6

   Clear Codes

   Clear the codes from the TIA/UIC and TCU, then test drive the machine to verify the transmission output speed registers on the live data/dash.