Case IH 9038 - UCM – UCM: Front hitch setpoint potentiometer short circuit to 12V

The control module is detecting an abnormally high voltage on the signal circuit for the front hitch position sensor, indicating that the signal wire is shorted directly to a 12-volt power source. This condition prevents the system from accurately reading the physical position or setpoint of the front hitch.

• VESTRUM CVX
• MXM120
• MXM130
• MXM140
• MXM155
• MX215
• MX285
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Maxxum Series

1. 1

   Inspect the wiring harness leading from the front hitch potentiometer to the UCM for rubbed or chafed wires that could cause the signal wire to short against a 12V power supply wire.

2. 2

   Unplug the connector at the front hitch potentiometer and the main connector at the UCM. Inspect the pins for corrosion, dirt, or water intrusion.

3. 3

   With the sensor unplugged and the key ON, verify the voltage at the sensor connector to determine if the short to 12V is in the wiring harness or internal to the potentiometer itself.

1. 1

   Repair or replace

   Repair the shorted wire in the front hitch harness or replace the internally shorted potentiometer.

2. 2

   Clear codes

   Clear the UCM fault codes.

3. 3

   Recalibrate

   Recalibrate the front hitch limits.