CLAAS Id7747h / 7747h (637 05) – ENG (A15): Intensity of the crankshaft position sensor low.

The engine control unit is detecting an abnormally low electrical current or an open circuit from the primary crankshaft position sensor (B231). The engine will continue to run normally in a degraded mode, relying on the secondary timing position sensor (B232).

• 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 (A15) for obvious physical damage.

2. 2

   Check the connectors and the continuity of the wiring harness linking the B231 sensor to the A15 Engine ECU. Look for rubbed wires, corrosion, or loose pins.

3. 3

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

4. 4

   Measure the internal resistance of the crankshaft position sensor to see if it falls outside of the manufacturer's specified range.

5. 5

   Verify the physical adjustment and air gap of the sensor against the crankshaft target wheel.

1. 1

   Locate the Sensor

   The crankshaft position sensor (B231) is located on the front of the engine block, near the timing cover and crankshaft torsional absorber.

2. 2

   Clear Access

   Depending on the specific tractor model (4-cylinder vs. 6-cylinder), you may need to remove the fan belt or navigate around the oil pressure controller to gain clear access to the sensor.

3. 3

   Disconnect Wiring

   Carefully unplug the 2-pin electrical connector from the sensor.

4. 4

   Remove Harness Clamps

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

5. 5

   Remove the Sensor

   Unbolt and remove the old crankshaft position sensor (B231) from the timing cover/engine block.

6. 6

   Install the New Sensor

   Insert the new sensor and tighten the mounting bolt to the specified torque (refer to your specific engine's torque overview).

7. 7

   Re-secure Wiring

   Fit and tighten the bolts securing the wiring harness clamps, ensuring the wire is routed safely away from moving belts and hot engine components.

8. 8

   Reconnect and Clear Codes

   Plug the 2-pin connector back in. Turn on the tractor's ignition and use the CLAAS Metadiag or equivalent diagnostic tool to clear the Id7747h / 637 05 fault code.