CLAAS Id787Bh / 787Bh – MFT (A30): Voltage delivered by the loudspeaker is too high

Voltage delivered by the loudspeaker is too high. The system response to this fault is that the loudspeaker of the Cebis terminal remains active.

• CLAAS Axion 800 series (810, 820, 830, 840, 850)
• CLAAS Axion 900 series (920, 930, 940, 950)
• CLAAS Arion 500 and 600 series (e.g., 510-640)

1. 1

   Inspect the loudspeaker (C22) of the Cebis terminal

2. 2

   Verify the connections at the Cebis Terminal Module MFT (A30)

3. 3

   Check the wiring harness between the MFT (A30) module and the C22 loudspeaker for any short-circuits to a power source or open circuits

4. 4

   Check the internal resistance of the loudspeaker component to ensure it has not failed internally

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes during testing.

2. 2

   Access the Terminal

   Remove the necessary trim panels on the right-hand console to access the rear of the Cebis terminal (MFT A30) and the loudspeaker (C22).

3. 3

   Inspect Wiring

   Visually inspect the wiring harness connecting the terminal to the loudspeaker. Look for chafed wires that might be shorting to a 12V source.

4. 4

   Test the Loudspeaker

   Disconnect the loudspeaker and test it with a multimeter. If the resistance is out of specification or shorted, replace the loudspeaker.

5. 5

   Test the Terminal Output

   If the wiring and loudspeaker are intact, the fault likely lies within the internal audio amplification circuitry of the Cebis terminal itself.

6. 6

   Replace/Repair

   Replace the faulty component (either the C22 loudspeaker or the MFT A30 terminal). Note that Cebis terminals are often sent out for specialized remanufacturing if the internal board fails.

7. 7

   Clear Codes

   Reconnect the battery, turn on the ignition, and clear the fault codes from the system memory.