Case IH 2087 – Transmission Control Unit (TCU): 1-4 range synchroniser solenoid - short to ground or high voltage

Electrical fault in the circuit controlling the solenoid responsible for shifting the transmission into the 1-4 gear range. The controller has detected that the circuit either has a direct path to ground (short circuit) or is exposed to a power source (short to battery/high voltage). This prevents the transmission from properly actuating the 1-4 range synchronizer, which can result in a loss of those gears or a transmission default/limp mode.

• Maxxum
• Puma 115
• Puma 125
• Puma 140
• Puma 155
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 135
• Maxxum 140
• Maxxum 145
• Farmall 95U
• Farmall 105U
• Farmall 115U
• Farmall 40
• Farmall 45
• Farmall 50
• Steiger Series

1. 1

   Trace the wiring harness from the Transmission Control Unit to the transmission valve block. Look for chafed insulation, pinched wires, or melted spots that could cause the wire to short against the tractor chassis (ground) or an adjacent power wire (high voltage).

2. 2

   Disconnect the electrical connector at the 1-4 range synchroniser solenoid. Inspect the pins for corrosion, moisture ingress, or damage.

3. 3

   Using a multimeter, measure the resistance across the pins of the solenoid coil. If the resistance reads at or near 0 ohms, the coil is internally shorted and must be replaced.

4. 4

   With the key ON (engine off) and the solenoid disconnected, check the harness-side connector for unintended voltage. If voltage is present when the controller is not commanding the solenoid, there is a short to power in the harness.

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Valve Block

   Locate the transmission control valve block. On most Puma and Maxxum models, this is mounted on the side of the transmission housing or under the right-hand side of the cab.

3. 3

   Identify the Solenoid

   Consult your specific model's service manual diagram to identify which specific solenoid on the block controls the 1-4 range synchronizer (often grouped with the 5-8 range solenoid, which triggers code 2088).

4. 4

   Removal

   Disconnect the electrical wiring harness connector from the solenoid. Remove the retaining nut or bolt at the end of the valve stem that secures the solenoid coil.

5. 5

   Replace the Coil

   Slide the faulty solenoid coil off the valve cartridge stem. Slide the new solenoid coil into place and secure it with the retaining nut/bolt. (Note: If the mechanical valve cartridge itself is sticking and needs replacement, unthread it from the manifold block—be prepared to catch a small amount of hydraulic fluid).

6. 6

   Reassembly

   Reconnect the electrical connector and reconnect the tractor's battery.

7. 7

   Clear Codes & Calibrate

   Turn the key on and clear the fault codes using the tractor's H-Menu or a diagnostic service tool. Warm the transmission oil to at least 60°C (140°F) and perform a transmission/synchronizer calibration procedure to ensure the TCU adapts to the new solenoid.