Case IH 518594-06 - ACM – ACM: High voltage on the front PTO engage switch

A circuit fault in the cab's Front PTO engage switch. A "voltage high" (06) typically indicates a short to power (B+).

• MAGNUM AFS Connect
• Magnum 200 AFS Connect
• Magnum 220 AFS Connect
• Magnum 250 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Verify the fault state by turning the key to the ON position without starting the engine to check if the code is active

2. 2

   Inspect the physical condition of the Front PTO switch located on the armrest console to ensure it is not physically stuck or damaged

3. 3

   Access the underside of the armrest and verify that the electrical connector to the Front PTO switch is securely plugged in

4. 4

   Inspect the armrest wire harness for pinched wires, chafing, or exposed copper that could be shorting to a power source (B+)

5. 5

   Back-probe the switch connector with a multimeter to verify if the ACM is sending the correct reference voltage

6. 6

   Test the switch with a multimeter for proper continuity when toggled between the ON and OFF positions

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground cable to prevent electrical spikes during repair.

2. 2

   Access the Armrest

   Carefully remove the trim panels or retaining screws on the ACM (Armrest Control Module) console to access the internal switch wiring.

3. 3

   Disconnect the Switch

   Unplug the wiring harness connector specifically routed to the Front PTO switch.

4. 4

   Test or Replace

   If your multimeter continuity test in the diagnostic phase showed the switch was internally shorted or open, remove the faulty switch from the armrest bezel and snap the replacement switch into place.

5. 5

   Repair Wiring (If Applicable)

   If the switch tested fine but the harness was damaged, repair the damaged section of the armrest wire harness using proper solder and heat-shrink tubing, or replace the armrest harness section if heavily damaged.

6. 6

   Reassembly

   Reconnect the switch, reassemble the armrest console, and reconnect the battery.

7. 7

   Clear and Verify

   Power up the tractor, clear the inactive fault codes from the display, and cycle the Front PTO switch to ensure the PTO engages and the code does not return.