John Deere 191.09 – CCU / ECM: Incorrect CAN Bus Message / Abnormal Update Rate - Transmission Output Shaft Speed

The control unit is either receiving an incorrect message, experiencing an abnormal update rate, or missing the CAN message entirely from the PTQ (Power Train Quad) Control Software regarding the transmission output speed.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 9470RT
• 9520RT
• 9570RT

1. 1

   Inspect CAN Bus network wiring and connections between the transmission output speed sensor, PTQ controller, and CCU/ECM for loose, damaged, or corroded wires.

2. 2

   Use a John Deere diagnostic tool (Service ADVISOR) to monitor CAN Bus messages and verify proper communication between the CCU/ECM and PTQ control software.

3. 3

   Check for electrical interference by ensuring proper grounding and shielding of the CAN Bus cables.

4. 4

   Inspect the physical condition of the Transmission Output Shaft Speed Sensor and its pigtail connector for damage, moisture intrusion, or debris.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Repair CAN Bus Wiring

   If the diagnostic checks revealed chafed wires, broken pins, or corrosion in the harness between the PTQ and the CCU/ECM, repair or replace the affected harness section.

3. 3

   Replace the Speed Sensor

   If the wiring is intact but the PTQ is not registering an output speed (causing the missing CAN message), locate the Transmission Output Shaft Speed Sensor on the transmission housing. Remove the retaining bolt, pull the old sensor out, and install the new sensor.

4. 4

   Update Software

   Check if there are any available software updates or patches for the ECU and PTQ control software, as John Deere occasionally releases updates to resolve CAN communication bugs.

5. 5

   Clear Codes and Test

   Reconnect the battery, clear the 000191.09 fault code using a diagnostic tool, and test drive the machine to ensure the transmission output speed registers correctly and the code does not return.