Case IH 28 – Transmission ECM: CLUTCH PACK (B) NOT CALIBRATED

While the key switch is in the "ON" position, the ECM detects that Clutch Pack (B) lacks a valid calibration value.

• JXC
• Case IH MX210
• Case IH MX230
• Case IH MX255
• Case IH MX285
• Case IH Puma
• Case IH Maxxum

1. 1

   Access the Calibration Menu (H1 menu) using the tractor's CDU, Electronic Service Tool (EST), or service tool 294084.

2. 2

   Run the H1 clutch calibration procedure and monitor for U codes (U27/U29 for values lower than 230 mA, U28/U30 for values higher than 480 mA).

3. 3

   If a U28 or similar code is thrown during calibration, check the solenoid valve circuit and the solenoid valve itself.

4. 4

   Test the reverse solenoid hydraulic pressure circuit to ensure proper fluid pressure is reaching the pack.

1. 1

   Attempt Electronic Calibration

   Connect the EST or use the onboard CDU to enter the H1 menu and initiate the Clutch Pack (B) calibration.

2. 2

   Inspect and Replace Solenoids

   If the calibration fails due to out-of-range mA values (U-codes), inspect the wiring harness to the transmission solenoids. If the circuit is intact, replace the faulty Clutch Pack B PWM solenoid valve.

3. 3

   Hydraulic Pressure Test

   If the solenoid is functioning electrically, test the hydraulic pressure circuit. A lack of pressure may indicate a failing pump, blocked passage, or internal leak.

4. 4

   Internal Transmission Repair

   If external levers, relay rods, and solenoids are functioning correctly but the clutch is dragging or failing to engage, the transmission-gearbox casing must be removed (splitting the tractor).

5. 5

   Replace Internal Components

   Inspect and replace worn internal components, such as Clutch Pack B, damaged synchronizers, or selection sleeves.

6. 6

   Re-calibrate

   After any hydraulic or mechanical parts are replaced, you must successfully complete the H1 calibration procedure to clear Code 28.