CLAAS Id7525h / 7525h – MFA (A100): Voltage of the signal specified by the engine speed memory 1 incoherent contact.

The system has detected an implausible or conflicting (incoherent) voltage signal coming from the engine speed memory 1 contact switch. As a direct system response to this fault, the engine speed memory 1 function is rendered inactive.

• Axion 800
• Axion 810
• Axion 830
• Axion 850
• Axion 870
• Axion 920
• Axion 930
• Axion 940
• Axion 950
• Arion 500
• Arion 600
• Arion 640
• Arion 650

1. 1

   Inspect the engine speed memory 1 contact switch (S178) for physical damage or sticking.

2. 2

   Inspect the wiring harness between the S178 switch and the MFA (A100) module, specifically Connector X5 for corrosion, loose pins, or short circuits.

3. 3

   Verify the condition and connections of the MFA (A100) armrest multifunction module itself.

1. 1

   Access the Armrest Control Panel

   Carefully disassemble the right-hand armrest control panel to access the internal switches and the MFA (A100) module.

2. 2

   Inspect Connector X5 / S178 Wiring

   Locate the engine speed memory 1 contact switch (S178). Disconnect its connector and inspect the terminals. Clean any corrosion and ensure the pins are seated tightly.

3. 3

   Test the Switch

   Using a multimeter, test the S178 switch for continuity and proper voltage output when toggled. The signal must be coherent (distinct open/closed voltage states without fluctuation).

4. 4

   Replace the Switch

   If the switch fails the continuity or voltage test, replace the S178 engine speed memory 1 contact switch.

5. 5

   Test the MFA Module

   If the switch and wiring harness test perfectly, the fault lies within the MFA (A100) armrest multifunction module failing to read the signal correctly. The module may require a software reflash by a dealer or complete replacement.

6. 6

   Clear Codes

   Reassemble the armrest, turn on the ignition, and clear the fault codes via the CEBIS monitor or dealer diagnostic tool. Test the engine speed memory 1 function to ensure it is active.