Case IH 18335: CAN Signal Error State: MFH Aggressivity Switch

A control module is receiving an 'error state' signal from the Armrest Control Module (ACML) regarding the Multi-Function Handle (MFH) Aggressivity Switch, indicating the ACML is unable to validate the physical position of the switch.

• VESTRUM CVX
• Magnum
• Puma
• Maxxum
• Vestrum

1. 1

   Inspect the physical aggressivity switch on the Multi-Function Handle for sticking, mechanical damage, or liquid intrusion.

2. 2

   Check if the ACML software is up to date. Some Case IH CVT models require an ACML software revision (e.g., SW Version 3.0) that relaxes error code parameters and increases the fault detection time from 50ms to 500ms to prevent false CAN signal errors.

3. 3

   Inspect the wiring harness connecting the MFH to the ACML for shorts to a high source or open circuits, which cause the switch to report incorrect phasing.

1. 1

   Disconnect battery

   Disconnect battery power before servicing the armrest console.

2. 2

   Access switch

   Disassemble the Multi-Function Handle / Armrest to access the aggressivity switch and its sub-harness.

3. 3

   Test and replace switch

   If the switch fails a continuity/phasing test, replace the switch or the entire MFH joystick assembly (depending on whether the switch is serviced separately on your specific model).

4. 4

   Replace ACML

   If the switch and wiring are intact, the ACML itself may be faulty and require replacement.

5. 5

   Calibrate armrest

   After replacing armrest components, a software calibration of the armrest controls via the EST (Electronic Service Tool) is usually required to clear the error state.