Case IH 2221 (6153.17) - DEC – DEC: Synchro 2 Solenoid - LSD short to GND

This fault code indicates an electrical circuit failure related to the Synchro 2 Solenoid. A Low Side Driver short to Ground means the ground path is permanently connected to the chassis or another ground source, preventing the controller from regulating the solenoid.

• MAXXUM T4E
• Puma
• Maxxum
• Magnum

1. 1

   Inspect the wiring harness between the DEC and the Synchro 2 solenoid for chafing, rubbed-through insulation, or pinched wires that could cause a short to the chassis.

2. 2

   Inspect connectors at both the solenoid and the DEC module for looseness, moisture intrusion, or bent pins.

3. 3

   Test the internal resistance of the Synchro 2 solenoid coil (normal resistance is typically around 10 Ω ± 2).

4. 4

   If wiring and solenoid test good, check for a DEC internal failure (internal Low Side Driver stuck closed).

1. 1

   Power Down

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

2. 2

   Locate the Solenoid

   Locate the Synchro 2 Solenoid valve on the side of the transmission housing control valve block.

3. 3

   Disconnect and Inspect

   Unplug the harness connector from the Synchro 2 solenoid. Inspect the pins for corrosion or damage.

4. 4

   Measure Resistance

   Using a multimeter, measure the resistance across the pins of the solenoid. If it reads as a dead short (0 Ω) or significantly out of spec, the solenoid is internally failed and must be replaced.

5. 5

   Check Harness for Shorts

   With the solenoid disconnected, measure the continuity between the Low Side wire on the harness connector and the tractor chassis ground. If there is continuity, the wiring harness is shorted and must be traced and repaired.

6. 6

   Replace Component

   If the solenoid is faulty, unbolt the retaining hardware, remove the old solenoid cartridge/coil, and install the new one. Ensure O-rings are lubricated with clean transmission fluid.

7. 7

   Clear Codes

   Reconnect the battery, power on the tractor, and use the instrument cluster or a diagnostic tool (like the Jaltest AGV or Case IH AFS display) to clear the fault codes and perform any necessary transmission clutch/synchro calibrations.