New Holland UCM 5124 – UCM: Right Joystick F-B Axis - In Range Fault

The Universal Control Module (UCM) has detected that the Right Joystick Forward-Backward (F-B) signal has failed. The fault triggers when the voltage on the sensor circuit (specifically X-CN4A pin 17 and X-CN1B pin 13) drops below 0.2 V or exceeds 4.8 V. Normal operating voltage for the sensor output is between 0.5 V and 4.5 V, with the neutral position resting at approximately 2.5 V. When active, the machine will default to a 'Limp Home' Ground Drive operating mode, restricting normal movement and boom operations.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• L313
• L316
• L318
• L320
• C227
• C232
• C238
• C327
• C330
• C332

1. 1

   Voltage Sweep Test: Using a multimeter, probe the Right Joystick F-B sensor output. In the neutral position, the voltage should read approximately 2.5 V.

2. 2

   Range Test: Slowly move the right joystick fully forward and fully backward. The voltage should change in a smooth, linear fashion between 0.5 V and 4.5 V.

3. 3

   Evaluate Results: If the voltage is not 2.5 V in neutral, or if the voltage change is erratic/jumps out of range, the joystick base/potentiometer has failed.

4. 4

   Harness Inspection: If the joystick passes the sweep test, inspect the wiring harness between the right joystick and the UCM. Look for corrosion, burnt pins in the connectors, or rubbed wires causing a short to ground or short to power.

5. 5

   Component Isolation: Temporarily plug in a known-good joystick or UCM to confirm the elimination of the fault before purchasing expensive replacement parts.

1. 1

   Preparation

   Park the machine on a level surface, lower the boom (if possible), turn off the engine, and disconnect the battery negative cable.

2. 2

   Access the Connector

   Locate the right joystick connector (designated as X-UJMR or similar), which is typically routed behind the operator's right-hand accent panel/console.

3. 3

   Remove the Faulty Joystick

   Remove the mounting hardware securing the right joystick base to the console. Carefully pull the assembly up and disconnect the main wiring harness.

4. 4

   Install the New Joystick

   Connect the new joystick assembly to the machine's wiring harness. Secure the joystick base back into the console using the original hardware.

5. 5

   Restore Power

   Reconnect the battery negative cable and turn the ignition key to the ON position.

6. 6

   Clear Codes & Calibrate

   Use an Electronic Service Tool (EST) or a CAN-bus DTC eraser to clear the inactive 5124 fault code from the UCM. Note: Installing a new EH joystick often requires a 'Joystick Calibration' procedure via the instrument cluster or service tool to teach the UCM the new exact neutral, minimum, and maximum voltage values.

7. 7

   Operational Test

   Start the machine and test the forward/reverse ground drive and boom raise/lower functions to ensure the Limp Home mode is deactivated and full hydraulic response has returned.