Case IH 18305 – ACML: CRPM2 Switch CAN Signal Error

The system is receiving an invalid, missing, or error-state signal from the Constant RPM 2 switch over the CAN network.

• VESTRUM CVX
• Farmall 80N
• Farmall 100N
• Farmall 100V
• Farmall 110N
• Farmall 110CL
• Farmall 120C
• Maxxum MXM120
• Maxxum MXM130
• Maxxum MXM140
• Maxxum MXM190
• Puma Series
• Magnum Series

1. 1

   Inspect the Constant RPM 2 (CRPM2) switch on the armrest console for physical damage, sticking, or liquid intrusion.

2. 2

   Check the wiring harness and connectors between the CRPM2 switch and the Armrest Control Module (ACML) for chafing, corrosion, or loose pins.

3. 3

   Verify the ACML is properly communicating on the CAN bus and check if there are other broader armrest communication fault codes present (indicating a module or bus failure rather than an isolated switch failure).

1. 1

   Power down the tractor and disconnect the battery.

2. 2

   Access the armrest console to reach the ACML and the CRPM switch cluster.

3. 3

   Replace the faulty CRPM switch if it has failed internally, or repair the damaged wiring harness between the switch and the ACML.

4. 4

   Reassemble the armrest, power on the tractor, and clear the fault codes to verify the repair.