John Deere 127 – PTP / TCU / PTI / CCU: Transmission Oil Pressure Signal

The transmission control module has detected an abnormal signal related to the transmission oil pressure. This indicates either a voltage issue within the sensor circuit or dangerously low oil pressure within the transmission, which may result in restricted transmission function.

• 6410
• 6000 Series
• 9120
• 9220
• 9230
• 9320
• 9330
• 9420
• 9430
• 9530
• 9630
• 6M Series
• 6R Series
• 9030 Series

1. 1

   Check transmission/hydraulic oil level (park on level surface, warm oil above 35°C/95°F, run at 1200 rpm for 3 minutes in Park, reduce to slow idle, shut off, and wait 5 minutes before checking sight glass). Do not check within 8 hours of transporting the tractor in higher gears

2. 2

   Inspect the transmission oil filter for restrictions or clogs

3. 3

   Remove and clean the transmission sump screen with solvent, and inspect the cavity for debris

4. 4

   Cycle tractor power by turning the key switch off or restarting the engine after returning the shift lever to Park to see if the fault clears

1. 1

   Locate the transmission oil pressure sensor

   The sensor's location varies by model (e.g., above the transmission filter on some 6000 series tractors, or on the front right-hand corner of the shift cover).

2. 2

   Inspect wiring and connector

   Visually inspect the wiring harness leading to the sensor for any signs of damage, corrosion, or loose connections. Clean the connector and ensure it is securely seated.

3. 3

   Test the pressure sensor

   Check for a change in the sensor's state by grounding it and applying low air pressure (e.g., 10 psi) to see if the dash warning light responds, or use a pressure gauge on the sensor port to verify actual oil pressure.

4. 4

   Replace transmission oil pressure sensor

   If oil level and filters are good and wiring is intact, the sensor is likely faulty. Disconnect the electrical connector and remove the old sensor using a 30mm deep well socket or crowsfoot wrench. Install the new sensor to manufacturer specifications and reconnect.

5. 5

   Replace transmission oil filter(s)

   If not already done during preliminary checks, replace the transmission oil filter(s) to ensure proper fluid flow.

6. 6

   Perform transmission calibration

   After changing the transmission oil and filter, perform a transmission recalibration if the shifting characteristics have changed.