CLAAS Id7746h / 7746h (637 02) – ENG (A15): Signal of the crankshaft position sensor non valid

The engine control unit is receiving an invalid, missing, or erratic signal from the crankshaft position sensor (Component B231). As a protective measure, the engine calculator reduces engine power by 20% per minute until it reaches 50% of its nominal power.

• Axion 800
• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Arion 410
• Arion 430
• Arion 510
• Arion 520
• Arion 530
• Arion 550
• Arion 610
• Arion 620
• Arion 630
• Arion 640
• Arion 650

1. 1

   Inspect the crankshaft position sensor (B231) and the engine module ENG (A15) for obvious physical damage.

2. 2

   Check the connectors and continuity of the wiring harnesses linking the B231 sensor to the A15 module.

3. 3

   Test the circuit for any short-circuits to ground, short-circuits to power, or open circuits.

4. 4

   Check the sensor's resistance and frequency signal output. Verify the sources of energy (fuses, 5V supply, and ground).

5. 5

   Ensure there is no mechanical seizing, excessive temperature, or debris interfering with the sensor's magnetic pickup.

1. 1

   Locate the Sensor

   Locate the crankshaft position sensor (B231) on the engine block (typically near the timing cover or flywheel housing).

2. 2

   Document Hardware

   Note the exact position of the bolts and nuts before removing them.

3. 3

   Free the Harness

   Remove the bolts securing the clamps on the wiring harness for the crankshaft position sensor to allow for slack.

4. 4

   Disconnect

   Unplug the 3-pin electrical connector from the sensor.

5. 5

   Remove Sensor

   Remove the mounting hardware and extract the B231 crankshaft position sensor.

6. 6

   Install New Sensor

   Insert the replacement sensor. If required by the specific engine model, ensure the component's adjustment/air gap is calibrated correctly.

7. 7

   Reassembly

   Secure the mounting bolts, reconnect the electrical plug, and reattach the wiring harness clamps.

8. 8

   Clear Codes

   Clear the error codes from the ENG (A15) module and test the tractor to ensure the anomaly does not reappear and full engine power is restored.