John Deere 191.03 – PTA (Power Train) / TCU (Transmission Control Unit): Sensor for Transmission Output Speed, Voltage at Channel 1 Too High

The control unit detects that the voltage at the signal input from channel 1 of the transmission output speed sensor is excessively high, indicating a short to power/battery in the sensor circuit or an internal failure of the sensor itself.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 6820
• 6920
• 6920S
• 5050E
• 5065E
• 5075E
• 5085E
• 5090E
• 310SK
• 315SK
• 6R Series
• 7R Series
• 8R Series
• 5000-series
• S690
• 250D
• 300D

1. 1

   Inspect the sensor circuit (lead 6081 for channel 1) between the transmission output speed sensor and the TCU/PTA for any signs of a short to power/battery.

2. 2

   Examine the connectors at the sensor and the module to ensure they are secure, clean, and free of corrosion or bent pins.

3. 3

   Use a multimeter to measure the voltage at the signal input of channel 1. If the voltage is pegged high and the wiring harness tests good, the sensor has failed internally.

4. 4

   Check for related codes (such as 000191.11 or 000191.02) which indicate a frequency discrepancy between the transmission output speed sensor and the wheel speed sensor.

1. 1

   Safety First

   Park the machine on a level surface, engage the parking brake, turn off the engine, and relieve any hydraulic pressure.

2. 2

   Locate the Sensor

   Locate the transmission output speed sensor on the transmission housing (labeled as sensor B63 or B14 depending on the model).

3. 3

   Disconnect the Harness

   Carefully unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Unbolt and remove the faulty transmission output speed sensor from the transmission housing. Have a catch pan ready, as a small amount of transmission fluid may leak.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor with clean transmission fluid (e.g., Hy-Gard) and install it into the housing. Torque the retaining bolt to OEM specifications.

6. 6

   Reconnect and Clear

   Reconnect the wiring harness. Turn the key on and use a diagnostic tool to clear the 000191.03 fault code from the PTA/TCU.

7. 7

   Test Drive

   Operate the machine to verify that the transmission shifts correctly and no longer defaults to manual mode.