Case IH 2380 – Transmission Control Unit (TCU) / Vehicle Control Module (VCM): No shaft 3 speed sensor fault

The transmission controller has lost the RPM signal from the 3rd shaft speed sensor inside the powershift transmission. When this signal is lost, the controller cannot verify the rotational speed of the 3rd shaft, which often causes the transmission to assume it is slipping, resulting in the tractor refusing to shift into higher gears (often limiting the tractor to 8th gear or lower) or shifting into neutral to protect the clutch packs.

• Steiger T4B
• Case IH Steiger Series: 350, 370, 385, 400, 420, 435, 450, 470, 500, 535, 540, 550, 580, 600, 620
• Case IH Quadtrac & Rowtrac Series: 370 through 620

1. 1

   Access the A-post display and navigate to the transmission diagnostics menu to monitor live data. Check the 3rd shaft RPM while driving or running the engine; if it reads '0' or shows highly erratic jumps while other shafts are normal, the sensor is likely dead.

2. 2

   Inspect the wiring harness leading to the sensor for physical damage, corrosion at the connector, or breaks. If related codes 2385 or 2386 (indicating shorts) are not present, the issue is usually a failed sensor probe.

1. 1

   Locate the Sensor

   The speed sensors for Shaft 3 and Shaft 4 are located on the lower left-hand side of the transmission, toward the rear. (Note: You may need to access this by sliding under the cab near the pivot joint).

2. 2

   Disconnect the Harness

   Unplug the electrical connector from the 3rd shaft speed sensor.

3. 3

   Remove the Sensor

   Remove the retaining bolt securing the sensor to the transmission housing and carefully pull the sensor out.

4. 4

   Retain the Spacer

   All three speed sensors on this transmission use the exact same part number, but they use different spacers to set the correct depth. You MUST remove the spacer from the old 3rd shaft sensor and install it onto the new sensor to ensure it sits at the correct depth.

5. 5

   Install the New Sensor

   Insert the new sensor (with the correct spacer installed) into the transmission housing and tighten the retaining bolt.

6. 6

   Reconnect and Clear

   Reconnect the wiring harness. Turn the key on, clear the fault codes in the A-post monitor, and test drive the tractor to verify that the shaft 3 RPM is now reading correctly and full shifting capability is restored.