Massey Ferguson 9090 – EEM3: Engine Speed Signal Evaluation Error

This fault code is technically defined as an "Engine speed signal, evaluation error". It is triggered by the Engine Control Unit (ECU) when it detects that the signals from the crankshaft speed sensor and the camshaft speed sensor are either defective or not in the correct phase relative to each other. The ECU relies on these two signals to accurately determine the engine's speed and the precise rotational position of its internal components. A discrepancy between these signals can lead to issues such as rough running, starting problems, or a complete shutdown of the engine.

• 5400 Series
• 5460
• 5465
• 5470
• 5475
• 5480
• 6400 Series
• 6485
• 6490
• 6495
• 6497
• 6499
• 7400 Series
• 7465
• 7475
• 7480
• 7485
• 7490
• 7495
• 7600 Series
• 8600 Series
• 8700 Series

1. 1

   Visually inspect the wiring harnesses and connectors for both the crankshaft and camshaft position sensors for frayed wires, broken wires, corrosion on pins, or loose connections

2. 2

   Disconnect the suspect sensor and measure its resistance with a multimeter (should be approximately 450 ohms +/- 20 ohms; an open circuit or out-of-spec value indicates a faulty sensor)

3. 3

   With the sensor and ECU disconnected, check the continuity of the signal and ground wires between the sensor connector and the ECU connector to rule out breaks

4. 4

   For active (three-wire) sensors, verify that the sensor is receiving the correct voltage (typically 5V or 12V) and has a solid ground connection

5. 5

   Visually inspect the tone/reluctor ring for damage such as missing or bent teeth, and ensure it is free from debris like metal shavings or mud

1. 1

   Isolate the faulty component

   Based on the diagnostic checks, determine whether the issue lies with the crankshaft sensor, camshaft sensor, wiring, or the ECU itself. If an additional fault code for a specific sensor (e.g., crank or cam sensor signal missing) is present, start with that sensor.

2. 2

   Sensor Replacement (if necessary)

   Disconnect the electrical connector from the faulty sensor. Remove the mounting bolt(s) and carefully extract the sensor from the engine block. Clean the sensor mounting surface to ensure a proper fit for the new sensor.

3. 3

   Sensor Installation and Adjustment

   Apply a light coat of anti-seize lubricant to the threads of the new sensor. Manually screw the new sensor in until it makes contact with the gear/tone ring. Back the sensor out by approximately 3/4 of a turn to set the correct air gap. Tighten the locknut to the specified torque, which is approximately 6 Nm. Reconnect the electrical connector, ensuring it is secure.

4. 4

   Final Steps

   Clear any stored fault codes using a diagnostic tool. Start the engine and verify that the fault code does not reappear. If the problem persists after replacing the sensors and verifying the wiring, the issue may be with the Engine Control Module (ECU).