Massey Ferguson 91.03 – Engine Control Unit (ECU): Engine Throttle Sensor Voltage Issue

Triggered when the control unit measures a voltage in excess of the normal operating range (typically greater than 4.7 volts) at the signal input of the accelerator pedal potentiometer. This high voltage reading indicates that the sensor circuit is either shorted to a power supply lead or has an open ground circuit.

• 4710
• 7724S
• 5712SL
• 7722
• 7722S
• 5613
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 4708
• 5608
• 7726S
• 4707
• 4709
• 5711SL
• 7718S
• 5610
• 7719
• 7714
• 7716S
• T4 (2015-2021)
• 5612
• 7720
• Tier 4 (2015-2021)
• 5611
• 7715S
• 5609
• 7724

1. 1

   Visual Inspection: Inspect the accelerator pedal assembly and its wiring harness for physical damage, debris, or moisture.

2. 2

   Connector Check: Disconnect the throttle position sensor (TPS) and check the pins for corrosion, bent terminals, or loose connections.

3. 3

   Voltage Test: Use a multimeter to measure the voltage at the TPS signal wire with the key ON. A reading above 4.7V confirms the 'Out of Range High' condition.

4. 4

   Harness Continuity: Check the wiring harness between the pedal and the ECU for continuity. Specifically, test for a short to power (which would cause the high voltage) or a broken/open ground wire.

5. 5

   ECU Verification: If the wiring harness is completely intact and the sensor tests fine, the issue may be internal to the ECU (e.g., damaged MOSFETs, micro-cracks in circuit traces, or degraded solder joints distorting the voltage interpretation).

1. 1

   Disconnect Power

   Disconnect the negative battery terminal to ensure safety and prevent electrical spikes.

2. 2

   Access the Sensor

   Locate the accelerator pedal potentiometer in the cab footwell.

3. 3

   Disconnect Harness

   Unplug the electrical connector from the throttle sensor.

4. 4

   Repair Wiring (If Applicable)

   If your diagnostic checks revealed a short or open wire in the harness, repair the damaged section of the wiring or replace the harness pigtail.

5. 5

   Replace Sensor (If Applicable)

   If the wiring is good but the sensor is faulty, remove the mounting bolts securing the throttle pedal/sensor assembly to the floorplate. Install the new throttle pedal potentiometer and secure the hardware.

6. 6

   Reassemble

   Reconnect the electrical harness to the new sensor.

7. 7

   Restore Power & Clear Codes

   Reconnect the battery. Turn the ignition key to the ON position and use a diagnostic service tool to clear the 000091.03 fault code.

8. 8

   Test Operation

   Start the tractor and test the throttle pedal operation to ensure smooth engine RPM response and verify that the code does not return.