CLAAS 7724h – ENG A15: Mixed Air Input Voltage Too High

The engine control module (ENG A15) has detected that the input voltage from the mixed air temperature sensor is too high. When this fault occurs, the system disregards the information coming from the faulty sensor. The engine will continue to run normally, but it will not use the mixed air temperature reading for any system calculations.

• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Arion 510
• Arion 610
• Arion 620
• Arion 630
• Arion 640

1. 1

   Visually inspect the mixed air temperature sensor (B223) for physical damage or corrosion.

2. 2

   Test the sensor's resistance using a multimeter set to Ohms (look for resistance changes with temperature; 'OL' indicates an open circuit, near zero indicates a short).

3. 3

   Perform a general electrical system check of connectors, wiring harness continuity, power sources, fuses, and ground connections for short or open circuits.

4. 4

   Check the engine module (ENG A15) for proper connections and correct functioning.

1. 1

   Locate the Mixed Air Temperature Sensor (B223)

   Locate the mixed air temperature sensor (B223) situated within the engine's air intake system.

2. 2

   Perform Diagnostic Tests

   Conduct the electrical and resistance tests on the sensor as described in the diagnostic checks.

3. 3

   Replace the Sensor if Faulty

   If the sensor is determined to be faulty, it should be replaced.

4. 4

   Inspect Wiring and Connectors

   If the sensor tests as functional, thoroughly inspect the wiring harness and connectors between the sensor and the engine module (ENG A15) for any damage, corrosion, or loose connections. Repair or replace any damaged wiring.

5. 5

   Clear Fault Codes

   After performing repairs, clear all error codes from the system.

6. 6

   Test Operation

   Operate the tractor to see if the fault code reappears. If it does, further diagnostics on the engine module (ENG A15) may be necessary, which might require assistance from a certified CLAAS service technician.