John Deere 84.14 – PTQ / EPC: Wheel Speed Sensor Missing On CAN BUS

The transmission control unit detects that power is flowing through the transmission (the clutch pedal is released and the reverse drive lever is in the forward or reverse position), but it is receiving absolutely no wheel speed signal. This condition forces the control software to limit transmission functionality. The root cause is typically a defective wheel speed sensor (B09 or B35) or a failure in the CAN BUS wiring preventing the sensor's data from reaching the controller.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 7130
• 7230
• 7330
• 7630
• 7730
• 7830
• 7930
• 6230
• 6330
• 6430
• 7430
• 7530
• 5080R
• 5090R
• 5100R

1. 1

   Restart the Tractor: Sometimes the code is triggered by a temporary communication glitch on the CAN BUS. Restart the engine to see if the active Diagnostic Trouble Code (DTC) clears or reappears.

2. 2

   Inspect the Sensor (B09/B35): Locate the wheel speed sensor on the transmission/chassis. Check for obvious physical damage, heavy debris buildup, or metallic shavings on the magnetic sensor tip.

3. 3

   Verify CAN BUS Wiring and Connections: Inspect the wiring harness leading from the sensor to the PTQ/EPC module. Look for loose connectors, chafed wires, or corrosion inside the connector pins.

4. 4

   Check Software Versions: Verify with a dealer if the transmission control software is up-to-date, as updates can sometimes resolve CAN BUS communication errors.

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, and turn off the engine. Disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate the Sensor

   Locate the B09/B35 wheel speed sensor (typically mounted on the transmission housing or rear differential case, depending on the exact tractor model).

3. 3

   Disconnect the Harness

   Carefully unplug the 2-pin or 3-pin electrical connector from the sensor.

4. 4

   Remove the Sensor

   Unbolt the retaining fastener holding the sensor in place and pull the sensor straight out of its bore.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor (if applicable) with clean transmission fluid. Insert the new sensor into the bore and tighten the retaining bolt to factory specifications.

6. 6

   Reconnect Wiring

   Plug the electrical harness back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Test Operation

   Reconnect the battery. Start the tractor and clear the stored fault codes via the CommandCenter display or a diagnostic tool. Test drive the tractor (engaging the transmission in forward and reverse) to ensure the code does not return and full transmission functionality is restored.