Case IH 2664-03 - ACM – ACM: Joystick 1 Theta-Axis Position - Voltage High

The voltage signal from the Theta-Axis of the joystick (proportional rocker switch on the multi-function handle) is above the normal operating range (usually reading a constant 5V or battery voltage). This indicates a short to a high voltage source, an open ground circuit, or an internal failure of the switch's potentiometer.

• MAGNUM AFS Connect
• Magnum
• Steiger
• Puma
• Maxxum
• CVX

1. 1

   Visual Inspection: Inspect the wiring harness running between the joystick rocker switch and the ACM for chafing, pinched wires, or exposed copper that could cause a short to power.

2. 2

   Connector Check: Examine the connector at the base of the joystick and the main connection at the ACM. Look for corrosion, bent pins, or loose terminals.

3. 3

   Voltage Sweep Test: Use a multimeter to measure the signal voltage from the rocker switch while moving it. If it reads a constant high voltage (e.g., 5V) regardless of the switch position, there is a short to a high source or the switch has failed internally.

4. 4

   Ground Circuit Verification: Verify that the ground circuit for the joystick switch is intact. An open ground will cause the signal voltage to float high, triggering the -03 fault.

1. 1

   Turn off the machine, engage the parking brake, and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Remove the armrest cover panels to access the base of the multi-function joystick and the ACM connections.

3. 3

   Disconnect the joystick harness from the ACM.

4. 4

   If the diagnostic checks revealed damaged wiring, repair or replace the affected section of the armrest harness.

5. 5

   If the wiring and ground circuits tested good but the switch failed the voltage test, the rocker switch or the entire joystick assembly must be replaced (depending on whether the switch is serviced separately for your specific model).

6. 6

   Install the new component and reconnect all harnesses.

7. 7

   Restore battery power and turn the key to the ON position.

8. 8

   Clear the inactive fault codes from the system.

9. 9

   Access the tractor's AFS Pro monitor to perform a joystick/armrest calibration procedure to ensure the ACM recognizes the full travel range of the new Theta-axis rocker switch.