Case IH 2227 (6154.17) - DEC – DEC: Synchro 3 Solenoid - LSD short to GND

The module has detected that the ground circuit for the 'Synchro 3' solenoid is shorted to the chassis or battery negative. This usually means the wire between the solenoid and the module is chafed and touching bare metal, or the solenoid coil itself has suffered an internal short circuit.

• MAXXUM T4E
• CX50
• CX60
• CX70
• CX80
• CX90
• CX100
• MX80C
• MX100
• MX120
• MX135
• MX150
• MX170
• MX200 to MX285
• Magnum 225
• Magnum 235
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Steiger 350 to 620
• Quadtrac 350 to 620
• Farmall 35C
• Farmall 105U
• Farmall 120C

1. 1

   Visually inspect the wiring harness from the Synchro 3 solenoid on the transmission valve block back to the DEC module for pinched wires, melted insulation, or areas rubbing against the tractor frame.

2. 2

   Disconnect the connector at the Synchro 3 solenoid and turn the key ON. Check the voltage at the module pin. It should read 12V in a normal OFF state. If it reads 0V, there is a short to ground in the wiring harness.

3. 3

   Measure the resistance across the two pins of the solenoid coil. A healthy coil measures between 6.8 Ohms and 7.3 Ohms. If it reads 0 Ohms, the coil is internally shorted and must be replaced.

1. 1

   Disconnect battery

   Turn off the tractor, remove the key, and disconnect the battery to prevent damage to the DEC module.

2. 2

   Locate solenoid

   Locate the Synchro 3 solenoid on the transmission control valve block.

3. 3

   Clean area

   Thoroughly clean the area around the solenoid to prevent dirt from entering the hydraulic system.

4. 4

   Disconnect connector

   Disconnect the 2-pin electrical connector from the solenoid.

5. 5

   Remove retaining nut

   Remove the retaining nut or bolt at the end of the solenoid stem.

6. 6

   Remove faulty coil

   Slide the faulty solenoid coil off the hydraulic valve cartridge. (Note: You usually do not need to remove the hydraulic cartridge itself, which prevents fluid loss).

7. 7

   Install new coil

   Slide the new OEM solenoid coil onto the stem and secure it with the retaining nut.

8. 8

   Reconnect plug

   Reconnect the 2-pin electrical plug.

9. 9

   Test transmission

   Reconnect the battery, turn the key on, and clear the fault codes from the DEC module. Test the transmission through its ranges to ensure the Synchro 3 engages properly.