Massey Ferguson 00.02.38 – Dash: Engine Speed Sensor Voltage Too High

The voltage reading returning from the engine speed sensor (crankshaft or flywheel position) is exceeding the maximum expected threshold. This condition is typically caused by a short-to-power in the sensor's wiring harness, a failed internal sensor component, or an incorrect sensor air gap. The Dash controller relies on this data to display RPMs and communicate with the transmission and engine controllers.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 3600 Series
• 4700 Series
• 5400 Series
• 5600 Series
• 5700 SL Series
• 6400 Series
• 6700 S Series
• 8400 Series
• 8700 Series

1. 1

   Visually inspect the sensor and connector pins for corrosion, moisture, or pushed-out pins

2. 2

   Perform a resistance test with the tractor stopped and the sensor disconnected at ambient temperature (should read approximately 450 Ohms +/- 20 Ohms)

3. 3

   Check for alternating voltage (AC) output from the sensor while the engine or gear is turning

4. 4

   Test the wiring harness between the sensor and the Dash/ECU for continuity, specifically checking for a short-to-power

1. 1

   Locate the sensor

   Find the engine speed sensor mounted on the flywheel housing or engine timing cover. Note: Access may require removing a rear tire or inner fender panels.

2. 2

   Remove the sensor

   Disconnect the electrical harness, remove the retaining bolt(s), and extract the sensor from the housing.

3. 3

   Clean the mounting surface

   Thoroughly clean the mounting area to ensure no dirt or debris prevents the new sensor from seating completely flush.

4. 4

   Install the new sensor

   Insert the new sensor, ensuring the sensor gap is correct (verify no shims are missing for a flush mount). Torque the retaining bolt to specification.

5. 5

   Reconnect wiring

   Plug the harness back in, ensuring the weather seal clicks securely into place.

6. 6

   Clear codes

   Turn the key to the ON position and navigate to the 'Clear Codes' or 'Reset Codes' option in the dash diagnostic menu to clear fault 00.02.38.

7. 7

   Verify repair

   Start the tractor and verify that the RPM gauge functions smoothly and the fault code does not return.