Deutz-Fahr M75 – Engine ECU (EMR): Crankshaft Speed Sensor Fault

The engine control system has detected that the speed signal from the crankshaft sensor is either lost, implausible, or invalid. This can prevent the engine from starting, cause it to stall, or force it into a derated power mode.

• Deutz-Fahr Series 5 tractors
• Agrotron series tractors
• Agrofarm series tractors
• Equipment utilizing Deutz engines (TCD 3.6, TCD 2.9, TCD 2012, TCD 2013, BFM1013)

1. 1

   Check the physical condition of the crankshaft speed sensor and its connector

2. 2

   Inspect the wiring harness for open circuits, short circuits to ground, or short circuits to battery voltage

3. 3

   Ensure high-amperage power wires are not routed too close to the sensor wiring to prevent electromagnetic interference

4. 4

   Check the position and mounting of the sensor relative to the trigger wheel to ensure the gap is correct and it has not vibrated loose

5. 5

   Ensure the trigger wheel (flywheel or crankshaft gear) is not damaged, missing teeth, or heavily coated in metallic debris

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Sensor

   Locate the crankshaft speed sensor. Depending on the specific Deutz engine model, it is typically mounted on the side of the front timing cover or near the flywheel/injection pump.

3. 3

   Remove the Sensor

   Disconnect the 3-pin electrical connector. Remove the retaining bolt and carefully pull the sensor out of the engine block or cover.

4. 4

   Clean and Inspect

   Clean the mounting port. Inspect the old sensor for physical damage or heavy metallic sludge.

5. 5

   Install the New Sensor

   Insert the new sensor. Most OEM replacement sensors come with a new O-ring pre-installed to ensure a proper seal. Secure it with the retaining bolt to the specified torque.

6. 6

   Reconnect and Clear Codes

   Reconnect the 3-pin wiring harness. Reconnect the battery. Use a compatible diagnostic scan tool (such as SERDIA or Jaltest) to clear the M75 / SPN 190 fault code from the EMR.

7. 7

   Test Run

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