Massey Ferguson 29.03 – Engine Control Unit (ECU): Engine Throttle Sensor Voltage Issue

Secondary Analog Throttle Signal (Hand Throttle Potentiometer / Throttle 2 sensor) is Out of Range High. The measured voltage signal from the hand throttle sensor to the controller is above the normal operating range (typically exceeding 3.0 volts), usually caused by an open circuit, a short circuit to the battery/power supply, or a defective potentiometer.

• 7724S
• 5712SL
• Interim Tier 4 (2012-2015)
• 7722S
• 7722
• 7615
• 5613
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7616
• 7618
• 5608
• 7619
• 7626
• 7726S
• 7624
• 5711SL
• 7614
• 7718S
• 5610
• 7620
• 7719
• 7714
• 7716S
• 5612
• 7622
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724
• 7600 Series
• 5600 Series
• 5700 Series
• 5709
• 5710
• 5711
• 5712
• 5713
• 6400 Series
• 6480
• 6600 Series
• 6615
• 6700 Series
• 6713S
• 7400 Series
• 7700 Series
• 8400 Series
• 8600 Series
• 8700 Series

1. 1

   Check system voltage to ensure the battery and alternator are functioning correctly, as voltage spikes or drops can cause erratic sensor readings.

2. 2

   Inspect the wiring harness from the hand throttle potentiometer to the ECU for chafed wires, micro-cracks, or a short to the battery.

3. 3

   Verify that the throttle sensor is receiving the correct reference voltage (power supply) from the ECU and that the ground connection is solid.

4. 4

   Test the output voltage of the hand throttle potentiometer with a multimeter while moving the lever. A voltage stuck high (> 3.0V) or an open internal circuit indicates a failed sensor.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical shorts during the repair.

2. 2

   Access the Sensor

   Locate the hand throttle potentiometer switch assembly inside the cab console/armrest.

3. 3

   Clean and Inspect Connections

   Disconnect the electrical connector to the sensor. Clean the terminals with contact cleaner and a wire brush to remove any corrosion. Apply dielectric grease to ensure a solid connection.

4. 4

   Repair Wiring

   If the diagnostic checks revealed a broken wire or short circuit in the harness, repair or replace the damaged section of the wiring.

5. 5

   Replace the Sensor

   If the wiring is intact but the sensor failed the multimeter test, remove the mounting hardware securing the hand throttle potentiometer and install the replacement OEM part.

6. 6

   Reassemble and Clear Codes

   Reconnect the sensor and the battery. Turn the ignition on, use a diagnostic tool to clear the 000029.03 fault code from the ECU, and test the hand throttle to ensure smooth RPM response and that the code does not return.