Massey Ferguson T4107 – Transmission Control Module (TRANS / TCU): Signal error - 8.5 V supply error

The transmission controller detects that the 8.5-volt reference supply to the high-pressure sensor is out of range, shorted, or missing, resulting in an invalid signal voltage.

• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 7615
• 7620
• 7616
• 7618
• 7619
• 7626
• 7624
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726
• 8670
• 8690

1. 1

   Verify the 8.5V supply by probing the connector for the Transmission High Pressure Sensor (X9/X34) using a multimeter.

2. 2

   Inspect the wiring harness between the sensor and the transmission controller for chafing, pinched wires, open circuits, or a short to ground.

3. 3

   Disconnect the sensor and inspect the connector pins for corrosion, moisture ingress, or pushed-out terminals.

4. 4

   Perform sensor isolation: disconnect the sensor to see if the 8.5V supply returns on the harness side, which indicates an internally shorted sensor.

1. 1

   Resolve Wiring Issues

   If the diagnostic checks reveal a wiring fault, repair the damaged section of the harness or replace the connector pigtail.

2. 2

   Replace the Sensor

   If the wiring is intact but the sensor is internally shorted or failing to read the pressure correctly, remove and replace the Transmission Oil High Pressure Sensor.

3. 3

   Perform Transmission Calibration

   A transmission calibration must be carried out systematically after changing the transmission high pressure sensor, the transmission control module, or the transmission itself. The calibration must be performed immediately after the range calibration. The hand brake must be applied (or ParkLock engaged), the Power Control lever must be in the neutral position, and the High/Low speed range (Hare/Tortoise) must be in neutral.