Case IH 6 – Electronic Draft Control (EDC) unit: Slip control voltage low (short or open circuit)

The controller is receiving a voltage signal from the wheel slip control potentiometer (or the radar speed sensor circuit it relies on) that is below the expected minimum threshold, typically caused by a short to ground, a broken wire (open circuit), a blown fuse, or a failed potentiometer/radar sensor.

• MXM
• Case IH MXM Series
• Case IH Magnum Series
• Case IH Puma Series
• Case IH Steiger Series

1. 1

   Verify if the instrument panel displays the correct tractor speed (if incorrect, the issue is likely the radar assembly circuit rather than the cab potentiometer)

2. 2

   Check the dedicated fuse for the radar/slip control circuit (identified as Fuse 9 in MXM/TM series)

3. 3

   Perform a harness wiggle test with the shuttle lever in neutral to check continuity between slip control connectors (e.g., C075 pin 4 and C534 pin 27)

4. 4

   Perform a voltage test to check for the presence of approximately +12 Volts supply to the sensor

5. 5

   Test for a short to ground (e.g., check between connector C068 pin 1 and ground)

1. 1

   Inspect Wiring

   Visually inspect the wiring harness and connectors leading to the wheel slip control potentiometer (located on the armrest/Multicontroller) and the radar assembly (mounted under the cab/chassis). Look for chafed wires or loose pins.

2. 2

   Address Fuse Issues

   If the voltage test yielded less than +12 Volts, inspect the circuit fuse. If blown, replace it. If it blows again immediately, proceed to step 3 to find the short.

3. 3

   Repair Open/Short Circuits

   If an open circuit was indicated during the diagnostic continuity test, repair or replace the damaged section of the wiring harness. If a short circuit was found, locate the pinched or exposed wire grounding out against the chassis and repair it.

4. 4

   Replace Sensor/Radar

   If the harness, connectors, and fuses are all in good condition and the supply voltage is correct, the fault lies within the component itself. Remove and replace the slip control potentiometer or the radar assembly.

5. 5

   Verify Repair

   Clear the fault codes from the EDC/Hitch controller. Test the tractor's hitch and slip control functions during operation to verify the code does not return.