New Holland NH 3093 – Engine Control Module (ECM / ECU): Engine Speed Sensing - SOURCE HIGH

The engine control system is detecting a voltage signal from the engine speed sensor that exceeds the maximum expected threshold (a short to power condition), or the synchronization/timing offset between the camshaft and crankshaft signal wheels is implausible or out of the acceptable mechanical range.

• T4
• T5
• T6
• T7
• T8
• T9
• TG
• TJ
• TD5
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• B90B
• B110B
• B115B

1. 1

   Inspect the wiring harness between the engine speed sensor and the ECM for chafed wires that may be shorting to a 12V or 5V power source.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, water ingress, or bent pins that could bridge the signal wire to a power wire.

3. 3

   Remove the engine speed sensor and inspect the magnetic tip for metal shavings or debris that could distort the signal.

4. 4

   Verify the correct physical positions of the camshaft and crankshaft signal wheels to ensure the timing gears have not slipped (mechanical timing check).

5. 5

   Test the sensor's resistance and output voltage with a multimeter while cranking to determine if the sensor has failed internally.

1. 1

   Safety First

   Turn off the machine, remove the key, and disconnect the negative battery terminal to protect the ECM.

2. 2

   Locate the Sensor

   Locate the engine speed sensor (crankshaft or camshaft position sensor) on the engine block or timing cover.

3. 3

   Test/Repair Wiring

   If the diagnostic checks revealed a short to power in the harness, repair the damaged section of the wiring loom or replace the pigtail connector.

4. 4

   Replace the Sensor

   If the wiring is intact and tests confirm the sensor is outputting out-of-range high voltage (or is internally shorted), remove the mounting bolt and pull the old sensor out.

5. 5

   Install New Sensor

   Lightly lubricate the O-ring on the new OEM engine speed sensor with clean engine oil. Insert it into the port and torque the mounting bolt to OEM specifications.

6. 6

   Address Mechanical Timing

   If a new sensor and good wiring do not clear the code, the front timing cover must be removed to inspect the camshaft and crankshaft tone rings/gears for mechanical misalignment.

7. 7

   Clear Codes

   Reconnect the battery. Use an Electronic Service Tool (EST) to clear the inactive NH 3093 fault code from the ECM's memory.

8. 8

   Test Run

   Start the engine and verify that the RPM reads correctly on the dash and that the fault code does not return.