Case IH 5323 – UCM: Enhanced High-Flow Auxiliary Option: EHF Fwd/Rev Switch Short to Power

The control module has detected a voltage on the Enhanced High-Flow (EHF) Forward/Reverse switch circuit that is higher than the expected normal operating range, indicating the signal circuit is shorted to a 12V power source due to a wiring failure or an internal short within the switch.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR175
• L220

1. 1

   Inspect the EHF Fwd/Rev switch (typically located on the joystick/control handle) for physical damage, sticking buttons, or debris.

2. 2

   Inspect the wiring harness running from the EHF Fwd/Rev switch to the UCM for chafed wires, pinched harnesses, or exposed copper that might be making contact with a power source.

3. 3

   Disconnect the switch from the harness and use a multimeter to check if the short to power is present on the harness side. If the short disappears when unplugged, the switch is internally shorted. If the short remains, the wiring harness is at fault.

4. 4

   Inspect the electrical connectors at both the switch and the UCM for corrosion, moisture, or bent pins.

1. 1

   Power down machine

   Power down the machine and disconnect the battery to ensure safety.

2. 2

   Repair or replace wiring harness

   Based on your diagnostic results, if the wiring harness is shorted, locate the damaged section and repair the wiring or replace the affected harness section.

3. 3

   Remove shorted switch

   If the switch is internally shorted, remove the EHF Fwd/Rev switch from the control handle/panel.

4. 4

   Install new switch

   Install the new EHF Fwd/Rev switch and securely connect the electrical harness.

5. 5

   Reconnect battery

   Reconnect the battery.

6. 6

   Clear fault codes

   Turn the key to the ON position and use a diagnostic tool (or the machine's display) to clear the stored fault codes.

7. 7

   Test auxiliary system

   Test the Enhanced High-Flow auxiliary system in both forward and reverse to verify the repair and ensure the code does not return.