Case IH ICU14003 – ICU: Hyd Oil Filter Switch Closed to Ground on Power Up

The hydraulic oil filter pressure switch is electrically closed to ground at the moment the system is powered on. This is an abnormal state, as the switch should be open when the engine is off and there is no hydraulic pressure. This fault indicates a potential short circuit in the switch's wiring harness or an internal failure of the switch itself, which compromises the system's ability to monitor for a clogged hydraulic filter and pressure drops.

• Magnum 235
• Magnum 340
• Puma 160 CVT
• Maxxum 5240
• MX80C
• MX90C
• MX100
• MX100C
• MX110
• MX120
• MX135
• MX150
• MX170
• 5120
• 5130
• 5140
• 5220
• 5230
• 5240
• 5250
• 40XT
• 60XT
• 70XT
• 75XT
• 85XT
• 90XT
• 95XT
• 410
• 420
• 420CT
• 430
• 435
• 440
• 440CT
• 445
• 450
• 450CT
• 465
• 1825
• 1825B
• 1835C
• 1838
• 1840
• 1845C

1. 1

   Check hydraulic fluid level and condition to ensure it is not low or contaminated.

2. 2

   Inspect the hydraulic filter for clogs or severe restriction.

3. 3

   Visually inspect the hydraulic oil filter pressure switch and its wiring harness for damage, corrosion, loose connections, or areas where the harness may be rubbing.

4. 4

   Test the switch with a multimeter: disconnect the harness and check for continuity to ground with the engine off. Continuity indicates a shorted/failed switch.

5. 5

   Check the wiring harness for a short to ground in the wire leading from the ICU to the switch (if the switch itself tests open).

1. 1

   Safety First

   Park the tractor on a level surface, lower all implements to the ground, turn off the engine, and remove the key.

2. 2

   Clean the Area

   Thoroughly clean the area around the hydraulic filter and pressure switch to prevent contamination of the hydraulic system before disconnecting any components.

3. 3

   Replace the Hydraulic Oil Filter

   Place a drain pan underneath to catch residual fluid and replace the hydraulic oil filter, as a clogged filter may be a contributing factor to pressure issues.

4. 4

   Replace the Hydraulic Oil Filter Pressure Switch

   Disconnect the electrical connector, unscrew the old switch, clean the sealing surface on the filter housing, and install the new switch tightened to manufacturer specifications (avoid overtightening). Reconnect the harness.

5. 5

   Clear Fault Codes

   After the repair, start the tractor. On many Case IH models, the fault code will clear automatically if the issue is resolved. If the code remains, it may need to be cleared using a diagnostic tool or a specific key cycle sequence as outlined in the operator's manual.

6. 6

   Test Operation

   Run the tractor and operate the hydraulic systems to ensure everything is functioning correctly and that the fault code does not reappear. Check for any leaks around the new switch and filter.