Massey Ferguson 00.X.64 – Dash Module: Issue With Hydraulic Oil Temperature Signal Voltage (Dash)

The control module is receiving a voltage signal from the hydraulic/transmission oil temperature sensor that falls outside the expected operating parameters. This typically indicates an open circuit, a short to ground, a short to power within the sensor's wiring harness, or a complete failure of the sensor itself.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614 through 7626
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 5608 through 5613
• 4707
• 4708
• 4709
• 4710
• 8670
• 8690

1. 1

   Visually inspect the hydraulic oil temperature sensor (typically mounted on the transmission housing, hydraulic pump housing, or tandem pump).

2. 2

   Disconnect the wire harness from the sensor and inspect the connector for backed-out terminals, corrosion, moisture, or bent pins.

3. 3

   Check the wiring harness between the sensor connector and the Dash module for continuity, looking for chafed wires shorting to ground or power.

4. 4

   Test the sensor's internal resistance with a multimeter; infinite resistance (open circuit) or zero resistance (dead short) confirms internal failure.

1. 1

   Preparation

   Park the tractor on a level surface, turn off the engine, and relieve any residual hydraulic pressure if applicable. Allow the hydraulic oil to cool to a safe temperature.

2. 2

   Clean the Area

   Thoroughly clean the area around the sensor housing to prevent dirt or debris from entering the hydraulic system when the sensor is removed.

3. 3

   Removal

   Disconnect the electrical pigtail/connector. Using the appropriate wrench, carefully unthread the sensor. Note: Have a catch pan ready, as a small amount of hydraulic fluid will likely leak out.

4. 4

   Installation

   Thread the new sensor into the port. Tighten to the OEM torque specification (do not overtighten, as brass-bodied sensors can snap).

5. 5

   Reconnection

   Reconnect the electrical harness, ensuring the locking tab clicks into place.

6. 6

   Fluid Check & Clearing

   Top off the hydraulic/transmission fluid if a significant amount was lost. Turn the key to the ON position and use the Dash menu or a diagnostic tool to clear the 00.X.64 fault code. Start the tractor and verify the code does not return.