John Deere 000127.01 – TCU / PTP / PTI / CCU / PTQ: Transmission System Fault

The system has detected a fault within the transmission system, specifically related to low transmission oil pressure or an abnormal voltage reading from the transmission oil pressure sensor circuit. This indicates either a genuine low hydraulic pressure condition or a sensor/wiring malfunction. If left unresolved, this fault can lead to restricted transmission function or cause the system to disable movement entirely, defaulting the machine to neutral or park.

• 9230
• 9330
• 9430
• 9530
• 9630
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R

1. 1

   Check transmission and hydraulic oil level for low fluid

2. 2

   Visually inspect the transmission housing, lines, and cooler for external oil leaks

3. 3

   Check transmission oil filters for restrictions or clogs

4. 4

   Inspect the transmission filter bypass valve to ensure it is not stuck open

5. 5

   Cycle the tractor's key switch power to clear potential temporary electronic glitches

1. 1

   Correct oil level

   If the transmission/hydraulic oil level is low, top it up to the manufacturer's specified level using the correct type of hydraulic oil. Run the tractor and check if the fault code returns.

2. 2

   Replace transmission oil filter(s)

   If the oil level is correct but the code persists, replace the transmission oil filter(s). Note that some models, like the 9x30 series, may have two filters to change. Operate the tractor to see if the code clears.

3. 3

   Inspect and test pressure sensor and wiring

   Locate the transmission oil pressure sensor. Test the sensor's output voltage and compare it to specifications. Inspect the wiring harness and connectors between the sensor and the control unit for damage, corrosion, or loose connections.

4. 4

   Replace transmission oil pressure sensor

   If the sensor fails the voltage test or is otherwise determined to be faulty, replace it with a new sensor.