Case IH 18263 (518733.02) - ACML – ACML: Front Hitch Height Limit Enable Switch - error state

The system has detected an invalid signal, an open circuit, or a short circuit in the Front Hitch Height Limit Enable Switch. The control module cannot verify the operator's input, often disabling front hitch automated functions for safety.

• MAXXUM T4E
• VESTRUM CVX
• Case IH Magnum 235 - 340 (Series 4)
• Case IH Puma series
• Case IH Vestrum CVXDrive

1. 1

   Install the diagnostic connector (OEM tool #380000843) into the diagnostic socket and turn the ignition key switch to the ON position.

2. 2

   Use the 'h', 'm', and 'dimming' buttons on the instrument cluster to navigate the HH menus to H5 on the LC controller.

3. 3

   Select the H5 menu by depressing the 'dimming' button. The lower central display will show 'd _ _'.

4. 4

   Operate the Front Hitch Height Limit Enable Switch. The designated input code for this switch is 'd92'.

5. 5

   When the switch is operated, the code 'd92' should be displayed and an audible tone should be heard to indicate the correct function.

6. 6

   If the switch code is not displayed and the tone is not heard, perform a 'wiggle' test on the related wiring harness while watching the display or listening for the tone to locate the break or short.

1. 1

   Inspect wiring harness

   Inspect the armrest wiring harness for crushed wires, damaged insulation, or poor electrical contact at the switch connector based on the H5 diagnostic test.

2. 2

   Replace the switch

   If the wiring is intact but the switch fails to register the 'd92' code during the H5 test, remove the armrest trim, disconnect the switch pigtail, and install a replacement switch.

3. 3

   Update ACML software

   Check the ACML software version. Update to revised software (e.g., v3.0 or v3.1) to increase fault detection time from 50ms to 500ms, preventing nuisance codes caused by minor voltage fluctuations.

4. 4

   Clear fault codes

   Once the repair is complete, cycle the key, re-enter the diagnostic menu, and clear the stored ACML fault codes.