Case IH 518594-14 - ACM – ACM: Incorrect front PTO engage switch configuration

This fault indicates a configuration or signal mismatch regarding the front Power Take-Off (PTO) engagement switch. The controller is either receiving an invalid combination of electrical states from the switch, or the software is configured to expect a front PTO switch that is missing, malfunctioning, or improperly wired.

• MAGNUM AFS Connect
• Magnum series (250, 280, 310, 340, 380)
• Optum series (250, 270, 300)
• Puma series (150, 165, 175, 200)
• Maxxum and MXM series

1. 1

   Verify Tractor Build: Confirm whether the tractor is actually equipped with a front PTO. If the tractor does not have a front PTO, the ACM software configuration may have been incorrectly altered or corrupted, causing it to look for a switch that isn't there.

2. 2

   Visual Inspection: Inspect the yellow mushroom cap push-pull switch on the armrest console. Check for physical damage, sticking mechanical detents, or a broken knob.

3. 3

   Electrical Connection Check: Access the underside of the armrest console and inspect the sealed 4-pin rear electrical socket on the switch. Look for loose pins, micro-chaff/dust buildup, or moisture entry that could cause voltage dropouts.

4. 4

   Software/Configuration Check: Use the Case IH Electronic Service Tool (EST) to verify the ACM software version and ensure the front PTO configuration matches the physical hardware installed on the machine.

1. 1

   Reconfigure ACM software

   If the issue is purely a software configuration error on a tractor without a front PTO, simply reconfiguring the ACM via the dealer service tool will resolve the code. If the switch is faulty, proceed below.

2. 2

   Power down tractor

   Power down the tractor and disconnect the battery to prevent electrical shorts.

3. 3

   Remove trim panels

   Carefully remove the trim panels on the Multicontroller armrest to access the underside of the command console.

4. 4

   Disconnect switch harness

   Locate the front PTO engagement switch. Disconnect the integrated 4-pin inline male connection harness from the switch.

5. 5

   Remove retaining hardware

   Remove the locating screw or retaining clips holding the switch assembly in the console.

6. 6

   Replace switch

   Remove the faulty switch and install the replacement OEM electro-hydraulic PTO clutch solenoid actuator switch.

7. 7

   Reconnect electrical connector

   Reconnect the 4-pin electrical connector, ensuring the sealed terminal is fully seated to prevent dust ingress.

8. 8

   Reassemble trim

   Reassemble the armrest console trim.

9. 9

   Clear fault code

   Reconnect the battery, turn the key to the ON position, and use a diagnostic tool to clear the 518594-14 fault code from the ACM.

10. 10

    Test switch operation

    Test the mechanical pull-to-on / push-to-off action of the new switch to ensure the front PTO engages and disengages properly.