Case IH 18318 (4156.02, 4156.13, 518661.07, 520630.07) - ACML – ACML: Mouse Rear Hitch Fast Lower Switch ACML - error state

The control module has detected an implausible signal, open circuit, or short circuit coming from the Rear Hitch Fast Lower Switch (S117) located on the 'Mouse' (Multi-Function Handle).

• VESTRUM CVX
• Puma 125
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Maxxum Series
• Maxxum 135
• Magnum Series
• Magnum 290
• Optum Series
• Steiger Series

1. 1

   Inspect the S117 Rear Hitch Fast Lower Switch on the Multi-Function Handle for physical damage, sticking, or debris preventing it from returning to neutral

2. 2

   Access the armrest internals and inspect connector X846 for loose connections, backed-out pins, or corrosion

3. 3

   Test the wiring between the S117 switch and the ACML for continuity and shorts to ground

4. 4

   Ensure the ACML software is up to date, as outdated software can trigger false error states

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Disassemble the Armrest

   Remove the retaining screws on the armrest console cover to access the base of the Multi-Function Handle.

3. 3

   Disconnect Wiring

   Locate and disconnect the main harness connector (X846) from the bottom of the Multi-Function Handle.

4. 4

   Remove the Handle

   Remove the mounting hardware securing the Multi-Function Handle to the armrest console and lift the handle out.

5. 5

   Install the New Handle

   Seat the new Multi-Function Handle into the console and secure it with the mounting hardware.

6. 6

   Reconnect and Reassemble

   Plug in the X846 connector, ensuring the locking tab clicks into place. Reinstall the armrest console cover.

7. 7

   Clear Codes and Calibrate

   Reconnect the battery. Turn the key to the ON position, use the tractor's diagnostic display (or EST tool) to clear the 18318 fault code, and perform any required armrest/hitch calibrations.