Case IH U30 – Transmission Electronic Management Unit (EMU) / Transmission Control Module (ECM): Clutch pack (A) value higher than 480 mA

The system is detecting an abnormally high current draw (greater than 480 mA) or a short circuit in the Clutch Pack (A) PWM (Pulse Width Modulation) solenoid circuit. It can also indicate Clutch A (low) calibration is too high, meaning the maximum calibration test pressure was reached without the expected drop in engine RPM.

• JXC
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TN Series
• Magnum
• Puma
• TM Series
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190
• 60 Series
• JX
• T7000 series

1. 1

   Check the wiring harness for a short circuit between the ECM connector (e.g., connector 1, pin 10 and ECM connector 1, pin 6 wires) or shorted across the two solenoid coil terminals.

2. 2

   Disconnect the control panel and the connections on the ECM, then measure the electrical resistance of the clutch solenoid valve (A) coil using a digital multimeter (should be approximately 10 ohms).

3. 3

   Test the specific wires on the solenoid valve wiring harness to ensure they are not shorted to the ground.

4. 4

   Test the reverse solenoid hydraulic pressure circuit to ensure mechanical pressure is reaching the clutch pack.

1. 1

   Isolate the Battery

   Turn off the tractor and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Transmission Valve Block

   Locate the transmission control valve block where the PWM solenoids are housed (usually accessible on the side of the transmission housing).

3. 3

   Inspect and Repair Wiring

   If the multimeter tests in the diagnostic phase revealed a short to ground or a broken wire between the ECM and the solenoid, repair or replace the damaged section of the wiring harness.

4. 4

   Replace the Solenoid Valve

   If the wiring is intact but the solenoid coil resistance is out of specification (not ~10 Ω) or internally shorted, remove the retaining bolt/clip for the Clutch Pack (A) PWM solenoid and extract the valve. Lubricate the O-rings on the new solenoid valve with clean transmission fluid and install it.

5. 5

   Perform Transmission Calibration

   Anytime a PWM solenoid valve is replaced, a mechanical repair is effected, or the ECM is disconnected, you must perform a transmission clutch and synchronizer calibration procedure using the tractor's H-Menu/electronic display so the ECM can relearn the new valve's engagement profile.