John Deere 191.02 – PTI, PTP, or TCU: Transmission Output Speed Mismatch

The controller generates this code when there is a frequency discrepancy between the actual signal from the transmission output speed sensor (B63) and the calculated expected speed (derived via the CAN BUS from the wheel speed sensor, B84) by more than 200 RPM.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7020 Series
• 7720
• 7820
• 7920
• 8R Series
• 8320R IVT
• 7R Series
• 7310R
• 6M/6R Series
• 6820
• 6920
• 6100MC
• 6110RC
• 5E Series
• 640H
• 648H
• 644
• 250D
• 300D

1. 1

   Scan for additional DTCs (especially those related to the CAN bus, wheel speed sensors, or voltage irregularities). If secondary codes exist, resolve them first.

2. 2

   Attempt a system reset by restarting the tractor or returning the shift lever to Park to clear temporary communication glitches.

3. 3

   Inspect sensor alignment to ensure both the transmission output speed sensor (B63) and the wheel speed sensor (B84) are correctly aligned, seated, and free of metallic debris on their magnetic tips.

4. 4

   Examine wiring harnesses and connectors between the sensors and the transmission control unit for chafing, corrosion, disconnections, or shorts to ground.

1. 1

   Test the Sensor Circuit

   Use a multimeter to measure the voltage at the signal input of the transmission output speed sensor (B63). Ensure the sensor is receiving proper reference voltage (usually 12V DC for Hall effect sensors) and that the ground circuit has a voltage drop of less than 0.1V under load.

2. 2

   Repair Harness

   If continuity is broken or a short is found, repair or replace the damaged section of the wiring harness or the connector.

3. 3

   Replace the B63 Sensor

   If the wiring is intact but the sensor output signal remains erratic, noisy, or dead, replace the Transmission Output Speed Sensor (B63). Clean the mounting area thoroughly before removing the old sensor to prevent dirt from entering the transmission housing.

4. 4

   Verify the B84 Sensor

   If the B63 sensor is replaced and the mismatch code returns, test the Wheel Speed Sensor (B84) and replace it if it is sending inaccurate CAN BUS data.

5. 5

   Recalibrate/Clear

   Clear the codes from the CommandCenter or diagnostic tool, heat the transmission oil to operating temperature, and test drive the machine (exceeding 8 mph) to verify the repair.