Case IH U15 – Rear Electronic Hydraulic Remote Valves: Valve 30 and Valve 31 Solenoid connectors swapped / Piston accumulator pre-charge pressure problem

The code officially indicates Valve 30 (upper lockout) and Valve 31 (lower lockout) Solenoid connectors are swapped. It may also indicate a piston accumulator pre-charge pressure problem, meaning the accumulator has lost its nitrogen pre-charge (flat) or is leaking, or there is an electrical fault in the pressure switch circuit.

• Case IH Mid-Range Magnum (MRM) 180
• Case IH Mid-Range Magnum (MRM) 200
• Case IH Mid-Range Magnum (MRM) 220
• Case IH Mid-Range Magnum (MRM) 240
• Case IH Puma 165
• Case IH Puma 180
• Case IH Puma 195
• Case IH Puma 210
• Case IH Puma 225
• Case IH Steiger

1. 1

   Check the wiring harness leading to the pressure switch for open circuits, short circuits, or damaged pins

2. 2

   Inspect the rear remote valve block to ensure the wiring harness connectors for Valve 30 (upper lockout) and Valve 31 (lower lockout) have not been accidentally swapped during previous service

3. 3

   Test the pressure switch for proper continuity and operation

4. 4

   Safely relieve hydraulic system pressure, then perform a manual check on the piston accumulator's nitrogen pre-charge to determine if it is leaky or flat

1. 1

   Depressurize the System

   Turn off the engine and cycle the hydraulic remotes to vent any residual pressure in the hydraulic circuit before servicing the accumulator or valves.

2. 2

   Correct Wiring Routing

   If the diagnostic check reveals that the solenoid connectors for Valve 30 and Valve 31 are swapped (the standard U15 condition), disconnect and reverse them to their correct respective solenoids.

3. 3

   Service the Pressure Switch

   If the wiring harness is intact but the switch fails continuity testing, remove and replace the pressure switch.

4. 4

   Service the Piston Accumulator

   If the manual pre-charge check shows the accumulator is flat, attempt to recharge it with nitrogen to the OEM specification. If it will not hold a charge (leaky), unbolt the accumulator assembly from the hydraulic block and install a new replacement unit.

5. 5

   Recalibrate

   Clear the stored fault codes from the electronic module and run a hydraulic remote valve calibration to ensure the system recognizes the corrected parameters.