New Holland UCM 5513 – UCM: Aux Control Function: Implausible State Sensor versus Auxiliary Command

This fault code indicates a mismatch between the electrical command sent by the UCM to the auxiliary hydraulic system and the actual physical position of the auxiliary valve spool. The UCM monitors the spool's movement via a spool position sensor. When the operator commands auxiliary hydraulic flow, the UCM expects the sensor to report a corresponding shift in the spool. If the sensor reports an implausible state, code 5513 is triggered.

• L213
• L218
• L220
• L223
• L230
• C227
• C238
• SR175
• SV185
• TR270
• SV300

1. 1

   Inspect the wiring harness leading to the auxiliary valve spool position sensor on the main EH control valve for chafed wires, loose pins, or corrosion inside the connector.

2. 2

   Verify that the sensor is receiving the correct reference voltage (typically 5V) and has a solid ground from the UCM.

3. 3

   Determine if the auxiliary spool is physically stuck. A stuck spool or a stuck Pressure Relief Valve (PRV) will prevent the spool from shifting when the solenoids are energized.

4. 4

   Monitor the sensor's signal voltage while commanding the auxiliary hydraulics. If the voltage does not change smoothly or is completely out of range, the sensor has likely failed.

1. 1

   Relieve Hydraulic Pressure

   Lower the loader arms, turn off the engine, and cycle the hydraulic controls to relieve all residual pressure in the system.

2. 2

   Access the Control Valve

   Locate the main EH loader control valve block, typically situated under the cab (the cab will need to be tilted and safely locked into place).

3. 3

   Inspect/Clean the Valve Spool

   If diagnostics point to a stuck spool, carefully remove the spool position sensor end cap. Inspect the spool and the bore for metal debris, scoring, or contamination. Clean the spool and bore. If the spool is heavily scored, the valve section may need to be replaced.

4. 4

   Replace the Sensor

   If the spool moves freely but the sensor output is erratic or dead, remove the faulty spool position sensor from the auxiliary section of the control valve.

5. 5

   Install New Components

   Install the new spool position sensor. It is highly recommended to replace the associated O-rings on the EH spool cap and passages during this process to prevent leaks.

6. 6

   Calibrate the Hydraulics

   After replacing the sensor or freeing a stuck spool, use the machine's display or a diagnostic service tool to perform an Electro-Hydraulic (EH) calibration. This allows the UCM to learn the new neutral, minimum, and maximum voltage values for the auxiliary spool sensor.

7. 7

   Test Operation

   Start the machine and test the auxiliary hydraulic functions to ensure smooth operation and verify that code 5513 does not return.