CLAAS Id7744h / 7744h (636 08) – ENG (A15) - Engine module: No signal from the position sensor of the high pressure pump

The Engine Control Unit is not detecting the input signal from the high-pressure fuel pump's position sensor. The engine defaults to a degraded mode, relying on the crankshaft position sensor to maintain operation.

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

1. 1

   Identify the position sensor of the high-pressure pump (Component B232)

2. 2

   Check the connectors and continuity of the wiring harnesses linking the B232 sensor to the A15 Engine Module

3. 3

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

4. 4

   Check the sources of energy (fuses, 5V reference supply, and ground) at the sensor connector

5. 5

   Check the component's resistance and frequency (Hz) output while the engine is cranking/running

1. 1

   Analyze Codes

   Note all error codes present on the tractor (via the Cebis panel or METADIAG tool) and analyze their interactions to ensure another electrical fault isn't causing the signal loss.

2. 2

   Inspect the Sensor

   Locate the B232 sensor on the high-pressure fuel pump (typically a Denso or Bosch pump). Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-out terminals.

3. 3

   Test the Harness

   Perform a continuity test on the wiring harness from the sensor pigtail back to the ENG (A15) module.

4. 4

   Replace the Sensor

   If the wiring is intact, power and ground are present, but no frequency signal is being generated by the sensor, the B232 position sensor has failed internally and must be replaced.

5. 5

   Clear and Verify

   Clear all error codes using the diagnostic tool, then test run the tractor to confirm the anomaly does not reappear.