Massey Ferguson 04.03.86 – TRANS: Transmission High Pressure Sensor Signal Voltage Issue

Triggered when the onboard diagnostic system detects an abnormal signal voltage (such as an open circuit, short to ground, or out-of-range value) from the sensor responsible for measuring the instantaneous oil pressure in the high-pressure hydrostatic system of the transmission.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 8690

1. 1

   Check transmission/hydraulic fluid levels and ensure fluid is not contaminated. Park on level ground with engine off and implements lowered.

2. 2

   Inspect the wiring harness for the transmission high-pressure sensor (designated as X34 and X9) for chafing, breaks, or shorts.

3. 3

   Disconnect the sensor and check connector pins for corrosion or pushed-out terminals. Use a multimeter to verify correct reference voltage and ground from the TRANS module.

1. 1

   Preparation

   Park the tractor on a flat surface, engage the ParkLock or hand brake, lower all implements to relieve hydraulic pressure, and turn the engine off.

2. 2

   Removal

   Disconnect the electrical harness from the transmission high-pressure sensor. Unthread the faulty sensor from the transmission housing (be prepared with a catch pan for a small amount of hydraulic fluid loss).

3. 3

   Installation

   Thread the new OEM sensor into the port and tighten to factory specifications. Reconnect the electrical harness.

4. 4

   Mandatory Calibration

   A transmission calibration procedure must be carried out systematically after changing the transmission high-pressure sensor. Preliminary conditions for calibration: Hand brake applied or ParkLock engaged, Power Control lever in neutral, and the High/Low (Hare/Tortoise) speed range in neutral.

5. 5

   Clear Codes

   Use a diagnostic tool to clear the 04.03.86 DTC from the TRANS module and test drive the tractor to ensure the code does not return.