Fendt B042 – ECU: EMR Crankshaft Sensor Position Issue

The Engine Control Unit (ECU) has detected an erroneous or lost signal from the crankshaft position sensor during Electronic Engine Control (EMR) operation. This sensor provides critical data on the rotational speed and position of the crankshaft, which is essential for controlling fuel injection timing and ignition. The fault is typically caused by an incorrect air gap between the sensor and the flywheel, damaged wiring, or a failed sensor.

• 300 series
• 400 series
• 700 series
• 800 series
• 900 series
• Farmer 400
• Favorit 700
• Favorit 900
• Vario 200
• Vario 300
• Vario 700
• Vario 800
• Vario 900

1. 1

   Retrieve fault codes using the onboard diagnostic system to confirm B042 and check for related codes like B041 (camshaft sensor).

2. 2

   Visually inspect the crankshaft sensor (typically located on the flywheel housing, engine block side, or front timing cover) and its wiring harness for frayed wires, loose connections, or corrosion.

3. 3

   Check the sensor mounting to ensure it is secure and that there is no debris between the sensor and the flywheel.

4. 4

   Measure the air gap between the sensor and the flywheel to ensure it is within manufacturer specifications (an incorrect gap is a common cause).

5. 5

   Test the wiring harness between the sensor and the ECU for continuity and potential short circuits.

6. 6

   Use Fendt-specific diagnostic software (SERDIA or EDT) to monitor live data from the sensor and access detailed troubleshooting plans.

1. 1

   Safety First

   Park the tractor on level ground, engage the parking brake, and disconnect the battery.

2. 2

   Locate the Sensor

   Identify the crankshaft sensor's location on the engine. This is typically on the flywheel housing.

3. 3

   Access the Sensor

   Remove any components that may be obstructing access to the sensor, such as covers or other parts.

4. 4

   Disconnect the Electrical Connector

   Carefully release the locking tab on the electrical connector and pull it from the sensor. Inspect the connector for any signs of corrosion or damage.

5. 5

   Remove the Old Sensor

   Unscrew the mounting bolt holding the sensor in place. Gently twist and pull the sensor to remove it from its housing. It may be snug due to an O-ring seal.

6. 6

   Install the New Sensor

   Compare the new sensor with the old one to ensure they match. Lightly lubricate the new sensor's O-ring with clean engine oil and insert it into the mounting hole.

7. 7

   Secure the New Sensor

   Reinstall the mounting bolt and tighten it to the manufacturer's specified torque. Do not over-tighten, as this can damage the sensor.

8. 8

   Reconnect and Reassemble

   Reconnect the electrical connector, ensuring it clicks into place. Reinstall any parts that were removed to gain access.

9. 9

   Clear Fault Codes and Test

   Reconnect the battery. Start the engine and use a diagnostic tool or the tractor's onboard system to clear the B042 fault code. Test drive the tractor to ensure the issue is resolved and the code does not reappear.