Case IH 5701 – UCM (Universal Control Module): Pattern Switch Open Or Shorted To Ground

The electrical circuit monitoring the joystick control pattern switch (which allows the operator to toggle between ISO and H operating patterns) has lost continuity (open circuit) or the signal wire has chafed and is making direct contact with the machine's chassis/ground.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR130
• SR160
• SR175
• TR270
• TR320
• TV380
• TV450

1. 1

   Verify the Symptom: Check the text display on the instrument panel to see if the control pattern switch state is registering. The switch should illuminate only on the selected side (ISO or H).

2. 2

   Inspect the Switch: Remove the switch from the instrument panel and inspect the rear connector for loose pins, pushed-out terminals, or corrosion.

3. 3

   Test the Wiring Harness: Disconnect the harness from the pattern switch and the UCM. Using a digital multimeter, check the signal wire for continuity to ground. If there is continuity to ground, there is a short in the harness that must be located and repaired. Check for continuity from end-to-end on the signal wire. If there is no continuity, the wire is broken (open circuit).

4. 4

   Test the Switch: If the wiring harness tests good, use the multimeter to test the internal contacts of the rocker switch for proper open/closed states when toggled.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent electrical arcing.

2. 2

   Access the Switch

   Carefully pry or unscrew the instrument panel bezel where the Drive Pattern rocker switch is located.

3. 3

   Disconnect

   Unplug the electrical connector from the back of the pattern switch.

4. 4

   Harness Repair (If Applicable)

   If your diagnostic checks revealed a short to ground or open wire, trace the harness back to the UCM, locate the chafed or broken section, splice in a new section of wire using weather-sealed heat-shrink connectors, and re-loom the harness.

5. 5

   Switch Replacement (If Applicable)

   If the switch failed the continuity test, push the retaining tabs on the sides of the old switch to pop it out of the panel. Snap the new OEM rocker switch into the panel slot.

6. 6

   Reassembly

   Plug the electrical connector back into the switch, secure the instrument panel, and reconnect the battery.

7. 7

   Calibration/Testing

   Turn the key on, clear the inactive fault codes from the UCM, and press the pattern switch. Confirm that the switch illuminates on the selected side and that the joysticks respond in the correct ISO or H pattern.