New Holland NH 1066 – EDC (Electronic Draft Control) module: EDC Hydraulic Valve Raise Solenoid Short Circuit

Indicates that the electrical circuit controlling the solenoid valve responsible for raising the rear hitch (via the Electronic Draft Control system) has experienced a short circuit. The short could be internal to the solenoid coil itself or located within the wiring harness connecting the solenoid to the control module.

• T5.95
• T5.105
• T5.115
• T6010 through T6070
• T7 Series
• TM115
• TM125
• TM175
• TL70A
• TL80A
• TL90A
• TL100A

1. 1

   Inspect the wiring harness between the EDC controller (XCM) and the EDC valve raise solenoid for chafing, pinched wires, or melted insulation that could cause a short to ground or another wire.

2. 2

   Disconnect the electrical connector at the EDC valve raise solenoid and use a digital multimeter to measure the resistance across the solenoid coil pins to check for an internal short.

3. 3

   If the solenoid and harness test fine, verify that the EDC central controller is not internally shorted and is sending the correct voltage signal.

1. 1

   Safety First

   Park the tractor on a level surface, fully lower the rear hitch to relieve hydraulic pressure, turn off the engine, and remove the key.

2. 2

   Locate the EDC Valve

   Locate the Electronic Draft Control valve block, which is typically mounted at the rear of the tractor near the remote control valves.

3. 3

   Disconnect Wiring

   Disconnect the electrical harness connector from the Raise Solenoid.

4. 4

   Remove the Solenoid Coil

   Remove the retaining nut or clip holding the solenoid coil to the valve stem. Slide the old coil off the valve cartridge. (Note: You usually do not need to open the hydraulic system to replace just the coil).

5. 5

   Install the New Coil

   Slide the new solenoid coil onto the valve stem. Ensure any external O-rings or back-up rings are in good condition and properly seated. Secure it with the retaining nut/clip.

6. 6

   Reconnect Wiring

   Plug the electrical harness back into the new solenoid.

7. 7

   Clear Codes and Calibrate

   Turn the ignition on and clear the NH 1066 fault code using the tractor's instrument panel or a diagnostic tool. You must then perform the "EDC Valve Solenoids Calibration" procedure as outlined in the service manual to ensure proper hitch operation.

8. 8

   Test Operation

   Start the tractor and test the raise and lower functions of the rear hitch to confirm the repair.