New Holland NH 7016 – Transmission Control Module: Difflock Solenoid Stuck on

Indicates that the electro-hydraulic solenoid responsible for engaging the tractor's differential lock is mechanically stuck in the activated position, or the electrical circuit is experiencing a fault (such as a short circuit) that keeps the solenoid continuously energized.

• T4.75
• T4.100F
• T4.100LP
• T5.95
• T5.105
• T5.115
• T8
• T5060
• T5070
• T6010 through T6070
• TD55D through TD95D
• TL65 through TL100A
• TS110
• TM175
• 7635/L95
• 8870
• 4635
• 4835
• 5635
• 6635

1. 1

   Inspect the wiring harness and the 2-terminal connector leading to the differential lock solenoid for visible cable damage, broken wires, or short circuits to power/ground

2. 2

   Check the differential lock switch in the cab to ensure it is not physically stuck in the closed/engaged position or internally shorted

3. 3

   Test the voltage at the solenoid connector to see if the transmission controller is continuously commanding the solenoid 'on' due to a wiring short

4. 4

   Remove the solenoid and check for mechanical binding, damaged scraper rings, or debris inside the hydraulic valve spool that could cause the valve to stick open

1. 1

   Locate the differential lock solenoid valve assembly

   It is typically mounted on the rear transmission hydraulic manifold or the transmission support valve block.

2. 2

   Clean the area around the valve

   Thoroughly clean the area around the valve to prevent dirt and debris from entering the hydraulic system.

3. 3

   Disconnect the electrical connector

   Disconnect the 2-terminal plug-and-harness electrical connector from the solenoid.

4. 4

   Remove the solenoid coil or valve cartridge

   Depending on the specific valve assembly, either remove the retaining nut to slide the solenoid coil off the valve stem, or unscrew the entire electro-hydraulic valve cartridge from the manifold.

5. 5

   Inspect the hydraulic valve ports and scraper ring

   Inspect for contamination. If the valve is mechanically seized, replace the entire cartridge.

6. 6

   Install the new differential lock solenoid/valve assembly

   Install and tighten to the manufacturer's specified torque.

7. 7

   Reconnect the electrical harness

   Reconnect the 2-terminal plug-and-harness electrical connector to the solenoid.

8. 8

   Clear fault codes and test

   Clear the fault codes from the transmission controller using a diagnostic tool (or DTC eraser) and test the differential lock engagement/disengagement to verify the repair.