New Holland 1066 – EDC: EDC Raise Solenoid Short Circuit

The Electronic Draft Control (EDC) module has detected an electrical short circuit within the wiring or coil of the EDC hydraulic raise solenoid. Electrical current is diverting from its intended path, likely to ground, causing excessive current flow. This electrical issue prevents the proper electronic operation of the hydraulic valve responsible for raising the three-point hitch.

• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TM175
• TM190
• TL70
• TL80
• TL90
• TL100
• TL70A
• TL80A
• TL90A
• TL100A
• TS90
• TS100
• TS110
• TS115
• TS100A
• TS110A
• TS115A
• T4020
• T4030
• T4040
• T4050
• T8.380
• M100
• M115
• M135
• M160
• 8160
• 8260
• 8360
• 8560

1. 1

   Visually inspect the wiring harness leading to the EDC raise solenoid (typically located on the main EDC valve block) for physical damage, chafing, melted insulation, or corrosion on the connectors.

2. 2

   Check for low battery voltage, as New Holland electronics can be sensitive to low voltage and trigger erroneous fault codes. Ensure the battery is fully charged and the charging system is functioning.

3. 3

   Perform a solenoid resistance test: Disconnect the harness from the EDC raise solenoid and measure resistance across the two coil terminals. Expected resistance is 6 to 8 ohms. A reading close to 0 ohms indicates a short circuit within the coil.

4. 4

   Perform a wiring harness test: With the solenoid disconnected, check the wiring harness for a short to ground. Measure continuity between the signal wire pin in the harness connector and a clean chassis ground. Continuity indicates a short in the harness that must be repaired.

1. 1

   Prepare machine for service

   Ensure the tractor is on a level surface, the engine is off, the parking brake is engaged, and the key is removed. Relieve any residual pressure in the hydraulic system.

2. 2

   Locate and disconnect solenoid

   Identify the EDC valve block and locate the raise solenoid (often on the left-hand side of the valve). Disconnect the electrical connector from the solenoid.

3. 3

   Remove faulty component

   If replacing only the coil, remove the retaining nut on the end of the solenoid stem and slide the old coil off. If replacing the entire solenoid cartridge, unscrew it from the valve body (be prepared for hydraulic fluid leakage).

4. 4

   Install new part

   For a new coil, slide it onto the solenoid stem and secure with the retaining nut. For a new solenoid cartridge, lubricate the O-rings with clean hydraulic fluid, screw it into the valve body, and torque to manufacturer specifications.

5. 5

   Reconnect and test

   Reconnect the electrical harness securely. Start the tractor, clear the fault codes, and operate the three-point hitch to ensure the system is functioning correctly.

6. 6

   Calibrate EDC system

   If required, enter the tractor's diagnostic mode (e.g., 'H' routines) and follow the specific calibration procedure, which may involve setting the engine to a certain RPM and cycling the hitch controls.