CLAAS Id7528h / 7528h – MFA (A100) - Armrest Multifunction Module: Voltage of the signal specified by the engine speed memory 2 incoherent contact.

This indicates that the system is receiving an erratic, conflicting, or out-of-range voltage signal from the engine speed memory 2 button. As a result, the system registers the engine speed memory 2 function as inactive.

• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Axion 920
• Axion 930
• Axion 940
• Axion 950
• Axion 960
• Arion 510
• Arion 530
• Arion 550
• Arion 610
• Arion 620
• Arion 630
• Arion 640
• Arion 650
• Arion 660

1. 1

   Test the engine speed memory 2 contact switch (S179)

2. 2

   Verify the operation and software status of the MFA (A100) armrest multifunction module

3. 3

   Inspect the connectors and test the continuity of the harnesses linking the S179 switch to the A100 module to rule out a short or open circuit

1. 1

   Power Down

   Turn off the tractor, remove the key, and allow the CAN bus network to power down.

2. 2

   Inspect the Switch (S179)

   Locate the engine speed memory 2 button on the multifunction armrest. Check for physical damage, sticking, or debris lodged around the button that could cause an incoherent contact signal.

3. 3

   Test the Switch

   Carefully remove the switch or access its rear connector. Use a multimeter to test the switch for proper continuity when pressed and released. If the switch shows erratic resistance or fails to close/open the circuit cleanly, it has failed internally and must be replaced.

4. 4

   Inspect the Wiring Harness

   If the switch tests good, trace the wiring from the S179 switch to the MFA (A100) module. Look for pinched, chafed, or broken wires inside the armrest assembly.

5. 5

   Check Connectors

   Disconnect the harness at the A100 module. Inspect the pins for corrosion, bent terminals, or loose seating. Clean with contact cleaner and reconnect securely.

6. 6

   Module Verification

   If the switch and wiring are perfectly intact, the fault lies within the MFA (A100) module itself. It may require a software update or recalibration via the CLAAS Diagnostic System (CDS). If software updates fail to resolve the incoherent signal processing, the A100 module must be replaced.

7. 7

   Clear Codes

   After repairs, use the diagnostic terminal to clear the 7528h fault code and test the engine speed memory 2 function to ensure the repair was successful.