Case IH U19 – Transmission Control Module (TCU): Transmission oil temperature is below 10°C (50°F)

Transmission oil temperature is below 10°C (50°F). This is primarily a calibration-specific error code. It triggers when an operator or technician attempts to run a transmission, clutch, or fast-steer calibration procedure while the tractor's hydraulic/transmission fluid is too cold. The system intentionally locks out the calibration process to prevent inaccurate clutch fill times and pressures, which require the oil to be at normal operating viscosity.

• Puma/Mid Range Magnum
• MXM
• Farmall
• JXC
• Maxxum
• Maxxum Series (MXM 120, 130, 140, 155, 175, 190, Maxxum 110-145)
• Puma Series (130-240)
• Magnum Series (180-240)
• Farmall Series (90C, 100C, 110C, 120C, 95U, 105U, 115U Pro EP)
• MX Series (MX100, MX110, MX120, MX135, MX170)
• Steiger Series

1. 1

   Warm up the vehicle and attempt the calibration again

2. 2

   Check live transmission oil temperature reading in the diagnostic H-Menu (H1 or H9)

3. 3

   Verify that the correct temperature sensor type is set in the transmission module (menu H3, channel 7)

4. 4

   Check the transmission temperature sensor connection for an open circuit in the feed to the transmission module if the tractor is at operating temperature but the code persists

1. 1

   Fluid Warm-Up Cycle

   Start the engine and perform at least six shuttle maneuvers (Forward and Reverse) and at least six shift maneuvers (e.g., Dual Command 'Hi' and 'Lo'), engaging each clutch at least three times. This ensures the hydraulic circuit and all clutches are thoroughly warmed up.

2. 2

   Re-attempt Calibration

   Once the fluid is warm, re-enter the calibration mode. If U19 clears, the system is functioning normally and no repair is required.

3. 3

   Wiring Inspection

   If the code persists on a warm tractor, locate the transmission oil temperature sensor on the transmission housing. Disconnect the harness and inspect the pins for corrosion, moisture, or wire chafing that would cause an open circuit.

4. 4

   Sensor Replacement

   If the wiring is intact but the sensor fails to read the correct temperature, the sensor has failed. Relieve any system pressure, clean the mounting area, and unthread the old sensor (be prepared to catch a small amount of fluid).

5. 5

   Installation

   Install the new transmission oil temperature sensor. Use appropriate thread sealant if required by the specific sensor style to prevent fluid leaks.

6. 6

   Final Verification

   Reconnect the wiring harness, turn the ignition switch to the 'ON' position, verify the temperature reading in the diagnostic menu, and successfully complete the transmission calibration.