CLAAS Id7720h / 7720h (103 06) – ENG (A15): Intensity of the turbocharger speed sensor high.

This code indicates an electrical fault where the signal intensity (current/voltage) from the turbocharger speed sensor is excessively high. This typically points to a short circuit or an open circuit in the sensor's wiring harness, or an internal failure of the sensor itself. When this code is active, the engine continues to run normally, but the engine computer ignores the erroneous information delivered by the sensor.

• CLAAS Arion series (e.g., 640–510)
• CLAAS Axion series (e.g., 850–810)

1. 1

   Check the wiring harness for the turbocharger speed sensor for any signs of an open circuit or short circuit.

2. 2

   Check the turbocharger speed sensor itself (component B226).

3. 3

   Check the connections at the engine module ENG (A15) to ensure there is no pin damage or moisture intrusion causing the high-intensity reading.

4. 4

   Check the intake tract for boost leaks, as lack of pressure resistance can cause turbocharger over-spooling and erratic sensor behavior.

1. 1

   Locate the Sensor

   Identify the turbocharger speed sensor (B226) located on the turbocharger assembly.

2. 2

   Inspect Connectors

   Disconnect the sensor and inspect the electrical connectors for dirt, moisture, or corrosion. Clean and reseal the connectors if necessary.

3. 3

   Test the Wiring

   Trace the wiring harness from the B226 sensor back to the ENG (A15) module. Test for continuity and ensure there are no short circuits to power or ground.

4. 4

   Replace the Sensor

   If the wiring harness and module connections are intact and test within normal parameters, the internal circuitry of the turbocharger speed sensor has failed. Remove the mounting bolt, extract the old sensor, and install the replacement.

5. 5

   Clear Codes and Test

   Connect the CLAAS Diagnostic System (CDS), clear the active fault codes, and perform a test drive to ensure the engine module is receiving a valid speed signal and the code does not return.