John Deere 524109.1 – TCU: B84 Wheel Speed Sensor Fault

The PLC reports a faulty wheel speed sensor (B84) over the CAN BUS network, which may cause inaccurate wheel speed readings, performance issues, warnings, or the system entering a protective mode.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6030 Series
• 6230
• 6330
• 6430
• 6M
• 6R
• 7000 Series
• 8000 Series
• 7130
• 7230
• 7430
• 8110
• 8410
• 6130
• 6530
• 6930

1. 1

   Check for active PLC (Powertrain/Programmable Logic Controller) codes, as they take priority over this TCU code

2. 2

   Inspect the physical condition and mounting of the B84 wheel speed sensor to ensure it can provide accurate readings

3. 3

   Examine the B84 sensor wiring and connectors for physical damage, corrosion, disconnections, or shorts to ground/power

4. 4

   Verify PLC functionality to ensure it is correctly processing signals, and check if a software update is required

1. 1

   Address Priority Codes

   Read all system codes. If a PLC code is present alongside TCU 524109.10, diagnose the PLC code first.

2. 2

   Access the Sensor

   Locate the B84 wheel speed sensor on the transmission/drivetrain housing.

3. 3

   Harness Testing

   Disconnect the sensor and use a multimeter to test the harness back to the PLC for continuity, open circuits, or shorts to ground.

4. 4

   Repair Wiring

   If the harness fails the test, repair or replace the faulty wiring or connectors.

5. 5

   Replace the Sensor

   If the wiring harness tests good but the sensor is failing to provide accurate rotational speed readings, remove the retaining hardware and replace the B84 wheel speed sensor.

6. 6

   Clear and Test

   Reconnect the system, clear the TCU and PLC codes, and test drive the tractor to ensure accurate wheel speed readings and that the transmission does not re-enter protective mode.