Case IH 2086 – Transmission Control Module: 5-8 range synchroniser solenoid - open circuit

The control system has detected a break in the electrical circuit for the solenoid responsible for actuating the 5-8 gear range synchroniser. The underlying condition is typically a disconnected electrical plug, a broken wire in the transmission wiring harness, or an internal failure (open coil) within the solenoid itself.

• Maxxum
• Puma 115
• Puma 125
• Puma 140
• Puma 155
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Magnum T8.275
• Magnum T8.300
• Magnum T8.330
• Magnum T8.360
• Magnum T8.390
• Farmall 115U
• Farmall 40 CVT
• Farmall 45 CVT
• Farmall 50 CVT
• CVX

1. 1

   Access the H2 or H3 menu screens on the tractor's lower central display to view stored calibration values and confirm the active fault channel.

2. 2

   Inspect the wiring harness leading to the transmission side cover or bell housing for chafed wires, rodent damage, or disconnected plugs.

3. 3

   Disconnect the plug at the 5-8 range synchroniser solenoid and check for moisture, corrosion, or pushed-back pins.

4. 4

   Measure the resistance across the pins of the 5-8 range synchroniser solenoid. If the multimeter reads 'OL' (infinite resistance), the solenoid coil is open. If resistance is normal, the open circuit is in the wiring harness.

1. 1

   Park and secure tractor

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Locate solenoid

   Locate the 5-8 range synchroniser solenoid. Depending on the specific model, this is typically located on the transmission control valve block, either inside the transmission side cover or externally on the bell housing.

3. 3

   Clean area

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

4. 4

   Disconnect connector or repair wiring

   Disconnect the electrical connector. (If the diagnostic checks revealed a broken wire in the harness, repair the wire or replace the pigtail connector and skip to step 8).

5. 5

   Remove retaining hardware

   Remove the retaining bolts or snap ring securing the faulty solenoid.

6. 6

   Install new solenoid

   Extract the old solenoid. Lubricate the O-rings on the new replacement solenoid with clean transmission fluid and carefully install it into the valve block.

7. 7

   Secure and reconnect

   Secure the solenoid with its retaining hardware and reconnect the electrical plug.

8. 8

   Clear fault codes

   Clear the fault codes from the Transmission ECU.

9. 9

   Perform calibration

   Perform a transmission calibration procedure (often the H8 procedure) to ensure the synchronisers and clutches are properly calibrated. During calibration, the system will determine the current required to turn the input/output shafts at the required speed. You may also need to adjust the 'quickfill' settings (between 30 and 190 ms) so that the tractor does not move unexpectedly when engaging the clutches.