Massey Ferguson 00.00.4B – Dash: Issue With Hand Throttle Circuit, Open Circuit

The system is detecting an "open circuit" in the hand throttle control circuit. This means the electrical signal from the hand throttle potentiometer is missing or interrupted. This is typically caused by a disconnected plug, a broken wire in the harness, or a complete internal failure of the hand throttle potentiometer itself.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5700SL
• 7600

1. 1

   Visually inspect the electrical connector plugging into the hand throttle potentiometer for unplugged connectors, backed-out pins, or corrosion.

2. 2

   Using a multimeter, check the continuity of the wiring harness between the hand throttle connector and the Dash controller to look for pinched or broken wires.

3. 3

   Turn the key to the ON position and check for a 5V reference signal and a good ground at the throttle sensor connector.

4. 4

   Perform a sensor sweep test by measuring the resistance of the hand throttle potentiometer while slowly moving the lever. If the resistance reads 'OL' (Open Loop) or drops out entirely, the sensor has failed internally.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Console

   Remove the retaining screws and carefully pry up the plastic trim panels on the right-hand control console to expose the base of the hand throttle lever.

3. 3

   Disconnect the Sensor

   Unplug the electrical harness connector from the hand throttle potentiometer.

4. 4

   Remove the Assembly

   Remove the mounting bolts securing the hand throttle bracket/sensor to the console frame.

5. 5

   Install the New Part

   Mount the replacement hand throttle assembly or potentiometer switch and tighten the retaining hardware.

6. 6

   Reconnect and Reassemble

   Plug the electrical connector into the new sensor. Ensure it clicks securely into place. Reinstall the console trim panels.

7. 7

   Test

   Reconnect the battery. Turn the ignition on and verify that the Dash SIS (Setup and Information Screen) no longer displays the 00.00.4B error. Start the tractor and verify smooth engine RPM response when moving the hand throttle.