John Deere 177.04 – PTA / PTP / EPC / TCU / BIF: Transmission Oil Temperature Sensor Short to Ground / Voltage Too Low

The control unit has detected the voltage at the signal input of the transmission oil temperature sensor (often designated as lead 6062 or 6002, or the B60 sensor) is below the acceptable threshold. This typically indicates a short to ground within the sensor's circuit. When this occurs, the equipment cannot accurately read the transmission oil temperature, which may cause the system to enter a protective mode with limited operational capabilities.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6M Series
• 9230
• 9330
• 9430
• 9530
• 9630
• 6120-6520L Series
• 450J
• 550J
• 650J
• 750J
• 850J
• 770G
• 770GP
• 772G
• 772GP
• 540G-III
• 548G-III
• 210L EP

1. 1

   Visually inspect the wiring and connectors associated with the transmission oil temperature sensor for any signs of rubbing, melting, or shorting to ground

2. 2

   Ensure all connectors and terminals in the sensor circuit are secure, fully seated, and free of moisture or corrosion

3. 3

   Use a multimeter to measure the voltage at the sensor input to verify if the voltage is actually dropping out or if the sensor is providing out-of-range low voltage readings

4. 4

   Verify control unit functionality to ensure the PTA/TCU is correctly processing signals and that the software is up to date

1. 1

   Disconnect Power

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

2. 2

   Repair Wiring

   If the diagnostic checks revealed damaged wiring or a short to ground in the harness (leads 6062/6002), splice and repair the damaged wires, or replace the affected connector pigtail.

3. 3

   Replace the Sensor

   If the wiring harness tests good (no shorts to ground) but the sensor itself is internally shorted or providing low voltage, remove the faulty transmission oil temperature sensor and install a new one.

4. 4

   Reassemble and Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic tool or the onboard CommandCenter display to clear the 000177.04 fault code.

5. 5

   Test Operation

   Start the machine, allow it to reach operating temperature, and monitor the transmission oil temperature readings to ensure they are accurate and the code does not return.