CLAAS Id774Ah / 774Ah (637 08) – ENG (A15) - Engine module / Engine calculator: No signal from the crankshaft position sensor

The crankshaft position sensor (B231) indicates the engine's rotation speed and the precise crankshaft position. When this signal is lost, the engine management system relies on the timing position sensor (B232) on the high-pressure pump to manage engine speed, and the system enters a degraded mode: the engine calculator reduces engine power by 20% per minute until it reaches 50% of its nominal power.

• CLAAS Axion 800 series (810, 820, 830, 840, 850)
• CLAAS Arion 600 series (620, 640, 650)
• CLAAS Arion 500 series (510, 520, 550)
• CLAAS Arion 400 series (410, 430)

1. 1

   Check the crankshaft position sensor (B231) and the engine module ENG (A15).

2. 2

   Check the connectors and the continuity of the harnesses linking the sensor to the engine module.

3. 3

   Inspect the wiring for any short-circuits or open circuits.

4. 4

   Check the sources of energy (fuses, power supply, and ground).

5. 5

   Perform a resistance check, power check, and frequency check on the B231 sensor.

6. 6

   Check the component's adjustment and operating conditions (e.g., mechanical seizing, temperature).

1. 1

   Depending on the engine configuration and access, you may need to remove the crankshaft torsional absorber or access the timing cover area.

   Depending on the engine configuration and access, you may need to remove the crankshaft torsional absorber or access the timing cover area.

2. 2

   Locate the crankshaft position sensor (B231) on the engine block/timing cover.

   Locate the crankshaft position sensor (B231) on the engine block/timing cover.

3. 3

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

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

4. 4

   Remove the faulty crankshaft position sensor (B231).

   Remove the faulty crankshaft position sensor (B231).

5. 5

   Install the new crankshaft position sensor.

   Install the new crankshaft position sensor.

6. 6

   Fit and tighten the bolts securing the clamps on the wiring harness for the sensor, respecting the technical torque specifications for your specific engine.

   Fit and tighten the bolts securing the clamps on the wiring harness for the sensor, respecting the technical torque specifications for your specific engine.

7. 7

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

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