New Holland NH 3090 – Engine Control Unit (ECU) / Engine Control Module (ECM): Segment speed signal - NOT PLAUSIBLE

The engine control module is either receiving no signal from the camshaft position/speed sensor, or the signal it is receiving is out of phase and does not logically align (is "not plausible") with the data coming from the crankshaft speed sensor. When this occurs, the engine may be forced into a "Backup Mode" (operating on the crankshaft sensor only).

• T4.75
• T4.85
• T4.95
• T4.105
• T4.115
• T5.95
• T5.105
• T5.115
• T6 Series
• T7 Series
• T8 Series
• TJ Series
• L216
• L220
• L228
• C227
• C327
• Super Boom models
• ISM-DI
• ISM-IDI
• NEF engines

1. 1

   Check the camshaft speed sensor wiring harness and connectors for open circuits, short circuits, corrosion, or reversed connections.

2. 2

   Verify the physical offset between the camshaft and crankshaft speed sensors. The ECM relies on the correct position of both the camshaft signal wheel and the crankshaft signal wheel.

3. 3

   Ensure the sensor is receiving the correct reference voltage from the ECU (check for high/low voltage source codes like 3091, 3093, or 3094 which often accompany this issue).

4. 4

   Remove the sensor and inspect the magnetic tip for metal shavings or debris that could be blocking the segment speed signal.

1. 1

   Locate the Sensor

   Locate the camshaft speed sensor on the engine block (typically near the timing gear cover or cylinder head, depending on the specific engine model like the F5C or ISM-DI).

2. 2

   Disconnect the Battery

   Always disconnect the negative battery terminal before servicing engine electronics.

3. 3

   Remove the Sensor

   Unplug the wiring harness connector from the sensor. Remove the retaining bolt and carefully pull the sensor out of its bore.

4. 4

   Inspect the Signal Wheel

   Shine a flashlight into the mounting hole to inspect the camshaft signal wheel/tone ring for missing teeth or physical damage.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor with clean engine oil. Insert the sensor into the bore until it is fully seated.

6. 6

   Secure and Reconnect

   Tighten the retaining bolt to OEM torque specifications and reconnect the wiring harness, ensuring the locking tab clicks into place.

7. 7

   Clear Codes

   Reconnect the battery. Use the New Holland Electronic Service Tool (EST) or a compatible DTC eraser to clear the inactive 3090 fault code from the Engine ECU. Run the machine to verify the code does not return.