Case IH U29 – Electronic Management Unit (EMU): Clutch pack (A) value lower than 230 mA

During operation or transmission calibration, the engine RPM dropped too soon, indicating that the clutch pressure is not being controlled properly. The system has detected that the electrical current value for the Clutch A proportional solenoid is out of the acceptable range (below 230 mA), which usually points to an open circuit, a short circuit, or a failed solenoid valve breaking the torque path.

• JXC
• MXM120
• MXM130
• MXM140
• MXM155
• MXM175
• MXM190
• MX210
• MX230
• MX255
• MX285
• Maxxum Series
• Puma Series
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190
• T6000
• T7000

1. 1

   Inspect the main transmission harness connectors for dirt, corrosion, or physical damage.

2. 2

   Remove the cab floor access panel (if required) to access the transmission valve block. Disconnect the electrical connector to the Clutch A solenoid and use a multimeter to check the solenoid pins for an open or short circuit.

3. 3

   Disconnect the processor (EMU) connectors and check for a short to ground or an open circuit in the wiring harness between the EMU pins and the solenoid harness-side connector.

4. 4

   Test the clutch/reverse solenoid hydraulic pressure circuit to ensure a mechanical failure isn't causing a premature drop in engine RPM.

1. 1

   Prep the Machine

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the battery. Relieve any residual hydraulic pressure.

2. 2

   Access the Valve Block

   Locate the transmission control valve block. Depending on the model, this may require removing the cab floor mat and access panel.

3. 3

   Wiring Repair (If Applicable)

   If the diagnostic continuity test revealed a broken wire or short to ground in the harness between the EMU and the solenoid, repair or replace the damaged wiring harness section.

4. 4

   Remove the Solenoid

   If the wiring is intact but the solenoid failed the resistance test, disconnect the electrical connector from the Clutch A solenoid. Unbolt and remove the faulty solenoid valve from the transmission block.

5. 5

   Install the New Solenoid

   Clean the mounting surface on the valve block to prevent contamination. Install the new solenoid valve and tighten to OEM torque specifications. Reconnect the electrical connector.

6. 6

   Reassemble and Power Up

   Reinstall any removed access panels and reconnect the battery.

7. 7

   Recalibrate the Transmission

   Start the tractor and bring the transmission fluid up to normal operating temperature. You must perform the transmission auto-calibration procedure (via the H-Menu) so the EMU can relearn the correct fill times and engagement pressures for the new Clutch A solenoid.