New Holland NH 15012 – Steering Controller (KA): Split Valve spool stuck open

This code indicates a mechanical or hydraulic issue within the tractor's Fast Steer system. The Split Valve alters the steering ratio to reduce the number of steering wheel turns required lock-to-lock. When the split valve spool is physically stuck in the open position, the system cannot properly transition between standard and fast steering modes.

• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• T6 Series
• T8 Series
• T9 Series

1. 1

   Check hydraulic oil temperature to ensure it is up to operating temperature, as cold oil can cause sluggish spool movement

2. 2

   Verify if the Steering Controller is logging related electrical faults (e.g., 15006, 15007, 15008, 15009) which may falsely report the spool as stuck

3. 3

   Inspect the wiring harness and connectors leading to the Fast Steer manifold, specifically Connector X626 (LVDT) and Connector X627 (Change Valve Solenoid) for corrosion or damage

4. 4

   Check hydraulic filters and fluid condition for contamination, which is a primary cause of stuck valve spools

1. 1

   Depressurize the System

   Turn off the tractor and relieve all hydraulic pressure from the steering system.

2. 2

   Locate the Fast Steer Valve Block

   Identify the steering control manifold containing the split valve and change valve solenoids.

3. 3

   Disconnect Electronics

   Unplug the wiring harness from the Split Valve Position Sensor (LVDT) and the Change Valve Solenoid.

4. 4

   Remove the Spool

   Carefully extract the split valve spool from the valve body.

5. 5

   Inspect and Clean

   Inspect the spool and the internal bore of the valve block for scoring, burrs, or debris. Clean the spool and bore thoroughly with hydraulic solvent.

6. 6

   Replace if Damaged

   If the spool or the valve block bore is heavily scored, the valve assembly must be replaced, as tolerances are too tight for repair.

7. 7

   Reassemble

   Lubricate the spool with clean hydraulic oil and reinstall it along with the LVDT and solenoids.

8. 8

   Calibrate the System

   After repairing or replacing steering valve components, you must recalibrate the steering system. Failing to do so will trigger fault code NH 15024.