New Holland UCM 5212 – UCM: Ground Drive: Pin A Short to Power

The control module is detecting an electrical short circuit to a power source on the Pin A circuit of the left joystick's forward/reverse axis sensor. This short circuit disrupts the machine's ability to safely command movement.

• New Holland 200 Series
• L218
• L220
• C-Series CTLs
• SR130
• SR150
• SR175
• SV185
• SR200
• SR220
• SR250
• SV250
• SV300
• TR270

1. 1

   Turn off the machine and disconnect the battery negative cable or use the battery disconnect switch

2. 2

   Visually inspect the wiring harness connecting the Left Joystick to the UCM for pinched wires, rubbed insulation, or melted sections

3. 3

   Disconnect the left joystick and use a multimeter to test the harness side of Pin A on the left joystick connector for continuity to any power source

4. 4

   If the harness shows no short to power, isolate the component as the short is likely internal to the joystick's forward-back axis sensor

1. 1

   Power down the machine and disconnect the negative battery cable.

2. 2

   Gain access to the base of the left joystick and disconnect its electrical connector.

3. 3

   Test the wiring harness.

   If a short to power is found in the harness, trace the wire back to the UCM, locate the damaged section, and repair or replace the wiring harness.

4. 4

   Remove the faulty left joystick unit.

   If the wiring harness tests good, the fault lies within the joystick's internal sensor. Remove the mounting hardware for the left joystick and remove the faulty unit.

5. 5

   Install the new left joystick assembly and plug in the electrical connector.

6. 6

   Reconnect the negative battery cable and power on the machine.

7. 7

   Perform a ground drive calibration.

   Replacing or recalibrating these components can trigger code 1212 (Calibration Functions - Ground Drive Calibration Not Complete) until the calibration procedure is successfully finished.