Case IH 10 – Electronic Draft Control (EDC) module: Height limit control voltage low, short or open circuit

The signal voltage coming from the height limit control potentiometer (the knob used to set the maximum lift height of the 3-point hitch) has dropped below the acceptable threshold. This is typically caused by an open circuit, a short circuit to ground, or an internal failure of the potentiometer itself.

• MXM
• Maxxum 100
• Maxxum 110
• Maxxum 115
• Maxxum 125
• Maxxum 130
• Maxxum 135
• Maxxum 140
• Maxxum 145
• Maxxum 150
• Puma 115
• Puma 125
• Puma 140
• Puma 155
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Magnum 7200 series

1. 1

   Enter the tractor's diagnostic H-Menu (H9 Channel 31 on Maxxum/Puma models) to view the live signal value of the potentiometer.

2. 2

   Disconnect the EDC control panel harness, turn the key ON, and check for a steady +5 Volt reference supply at the connector.

3. 3

   With the tractor OFF, check resistance values at the EDC control panel connector (C120) between Pin 7 and Pin 1, and between Pin 7 and Pin 4.

4. 4

   Wiggle the harness while checking for continuity between the EDC connector and the central controller to rule out intermittent open circuits or chafed wires.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Access the EDC Panel

   Remove the trim panels on the right-hand operator console (armrest or side console, depending on the model) to access the underside of the Electronic Draft Control panel.

3. 3

   Disconnect Harness

   Unplug the main connector (C120) from the EDC panel.

4. 4

   Repair Wiring

   If your diagnostic checks revealed a short or open circuit in the wiring harness, repair the damaged section of the wire and apply heat-shrink tubing.

5. 5

   Replace the Control Panel

   If the wiring is intact but the potentiometer failed the resistance test, remove the mounting screws securing the EDC control panel. Install the new EDC control panel.

6. 6

   Reassembly and Calibration

   Reconnect the harness, reinstall the console trim, and reconnect the battery.

7. 7

   Clear Codes

   Turn the key ON, clear the stored fault codes, and verify that Code 10 does not return. You may need to perform a hitch calibration procedure via the H-Menu to sync the new potentiometer values with the XCM.