Massey Ferguson E974.04 – Engine ECU: Engine Throttle Sensor Voltage Below Normal or Shorted Low

The control module detects that the signal voltage from the accelerator pedal potentiometer has dropped below the minimum acceptable operating threshold (typically below 0.3V to 0.5V). This indicates a short to ground in wire E974, a broken/open wire, or an internal failure of the throttle sensor itself.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Inspect the foot throttle pedal assembly and its electrical connector for dirt, moisture, corrosion, or backed-out pins.

2. 2

   Trace wire E974 from the pedal to the ECU, looking for pinched, chafed, or melted insulation that could be shorting the signal wire to chassis ground.

3. 3

   Disconnect the throttle sensor, turn the ignition key to ON (engine off), and use a multimeter to verify the sensor is receiving a 5V reference signal and a solid ground from the ECU.

4. 4

   Test wire E974 for continuity between the sensor connector and the ECU pin, and test for continuity to ground to check for a shorted harness.

5. 5

   Perform a sensor sweep test by measuring the sensor's resistance with a multimeter while slowly pressing the pedal to check for internal potentiometer failure.

1. 1

   Turn off the tractor ignition and disconnect the negative battery cable to prevent electrical spikes.

   Ensure the tractor is powered down before beginning electrical repairs.

2. 2

   If the harness is faulty: Locate the shorted section of wire E974. Cut out the damaged section, splice in a new repair wire using solder and heat-shrink tubing, and secure the harness away from pinch points.

   Repair the wiring harness if continuity tests indicated a short to ground or open circuit.

3. 3

   If the sensor is faulty: Locate the mounting bolts securing the foot throttle pedal/sensor assembly to the cab floor.

   Begin removal of the failed throttle sensor assembly.

4. 4

   Unplug the electrical harness connector from the sensor.

   Disconnect the sensor from the tractor's wiring harness.

5. 5

   Remove the bolts and extract the old throttle assembly.

   Fully remove the faulty pedal assembly from the cab.

6. 6

   Install the new throttle sensor/pedal assembly and tighten the mounting hardware.

   Secure the replacement throttle assembly to the cab floor.

7. 7

   Reconnect the electrical harness and reconnect the battery.

   Restore electrical connections and power to the tractor.

8. 8

   Turn the key ON and clear the inactive fault codes.

   Depending on the specific Massey Ferguson model, a throttle pedal calibration procedure may be required via the tractor's dash menu or a dealer diagnostic tool (AGCO EDT) to allow the ECU to learn the new sensor's minimum and maximum voltage values.