Case IH 7 – Electronic Draft Control (EDC): Slip control voltage high (damaged potentiometer or short to +12 Volts)

The controller is receiving a voltage signal from the slip control potentiometer that exceeds the maximum expected threshold. This condition is typically caused by an internally shorted/damaged potentiometer or a wiring harness that has shorted to a positive voltage source (+12V).

• MXM
• Case IH MXM Series
• MXM 120
• MXM 135
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Case IH MX Series
• Magnum Series

1. 1

   Disconnect the slip control potentiometer and test its resistance/voltage sweep with a multimeter to see if it is internally shorted or out of specification

2. 2

   Check the wiring harness between the potentiometer and the EDC controller. Probe the signal wire to check for a short circuit to +12V

3. 3

   Inspect the central controller (XCM) or secondary controller (CFPS) connectors (e.g., C330). Ensure the connectors are not damaged, the pins are in the correct position, the fit is tight, and there is no corrosion

1. 1

   Isolate the Fault

   Based on the diagnostic checks, determine if the fault lies in the wiring harness or the potentiometer itself.

2. 2

   Repair Wiring (If Applicable)

   If a short to +12V is found in the harness, trace the wire, repair the damaged insulation or broken wire, and secure it away from pinch points.

3. 3

   Replace Potentiometer (If Applicable)

   If the harness tests good, remove the faulty slip control potentiometer and install the replacement OEM part.

4. 4

   Clear the Code

   Once the physical repair is complete, use the tractor's instrument cluster or a diagnostic tool to clear the error code from the controller's memory.

5. 5

   System Test

   Test the electronic draft/slip control system under load to ensure normal operation and verify that the code does not return.