Massey Ferguson E108.03 – Engine ECU: Ambient pressure sensor voltage above normal or open circuit

The controller is receiving a voltage signal from the ambient (barometric) pressure sensor that exceeds the maximum expected threshold. This almost always indicates an open circuit in the wiring harness, a disconnected sensor plug, or an internally failed sensor.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 8600 Series
• Dyna 4

1. 1

   Visually inspect the ambient pressure sensor and electrical connector for disconnected plugs, backed-out pins, moisture, or corrosion.

2. 2

   Trace the wiring harness between the ambient pressure sensor and the Engine ECU to check for chafing, breaks, or pinched wires that would cause an open circuit.

3. 3

   Use a multimeter to verify that the sensor is receiving the correct 5V reference voltage and has a solid ground from the ECU.

4. 4

   Connect the AGCO Electronic Diagnostic Tool (EDT) to monitor the live voltage output of the ambient pressure sensor to see if it is pegged at maximum voltage.

1. 1

   Disconnect battery

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

2. 2

   Locate sensor

   Locate the ambient pressure sensor (typically mounted on or near the engine intake manifold or air filter housing, depending on the specific engine model).

3. 3

   Disconnect sensor

   Depress the locking tab and carefully unplug the electrical connector from the sensor.

4. 4

   Remove sensor

   Unbolt or unscrew the faulty ambient pressure sensor from its mounting point.

5. 5

   Install new sensor

   Install the new OEM sensor and tighten it to the manufacturer's specified torque.

6. 6

   Reconnect harness

   Reconnect the electrical harness, ensuring the locking tab clicks securely into place.

7. 7

   Reconnect battery

   Reconnect the battery.

8. 8

   Clear fault code

   Connect a diagnostic tool (such as the AGCO EDT) to clear the inactive E108.03 / SPN 108 FMI 3 fault code from the Engine ECU memory.