Case IH 1044-07 - DEC – Transmission Control Unit (TCU) or Vehicle Control Module (VCM): Transmission hydraulic pump/motor mechanical system not responding or out of adjustment

The system's control module has commanded the transmission hydraulic pump or motor to achieve a specific pressure, flow, or position, but the mechanical response does not match the commanded value. This typically points to a failing transmission charge pump (which loses pressure as the oil warms up), a clogged suction screen, or a maladjusted control valve/linkage.

• MAGNUM AFS Connect
• Magnum Series (180, 190, 210, 225, 7110-7140)
• Puma Series (130, 145, 160, 185)
• Maxxum Series (125)
• MX Series (MX180, MX200, MX220, MX240, MX270)

1. 1

   Drain a small amount of hydraulic fluid to check for contamination and inspect/clean the transmission suction screen (a clogged screen will starve the pump).

2. 2

   Test charge pump pressure, low-pressure standby, and high-pressure standby using a hydraulic pressure test kit and flowmeter (if pressure drops as oil warms up, internal pump clearances are worn).

3. 3

   Test proportional solenoids and reverse valves on the transmission pump with a multimeter to verify coil resistance and inspect the wiring harness for damage.

4. 4

   Verify that the control lever potentiometers and mechanical linkages are properly adjusted (out-of-adjustment linkages cause mechanical response lag).

1. 1

   Preparation

   Park the tractor on a level surface, lower all implements, turn off the engine, and relieve all hydraulic pressure.

2. 2

   Drain Fluid

   Drain the transmission/hydraulic fluid into a clean receptacle.

3. 3

   Remove Suction Screen

   Remove the transmission suction screen, clean the housing, and install a new screen/filter.

4. 4

   Disconnect Pump

   Identify the transmission hydraulic charge pump. Disconnect the hydraulic lines (cap them to prevent contamination) and unplug the electrical connectors to the pump solenoids/sensors.

5. 5

   Remove Pump

   Remove the mounting bolts securing the pump to the transmission housing and carefully extract the pump assembly.

6. 6

   Install New Pump

   Install the replacement or remanufactured pump using new O-rings and gaskets. Torque the mounting bolts to the specifications listed in your specific model's service manual.

7. 7

   Reassemble and Fill

   Reconnect all hydraulic lines and electrical harnesses. Refill the transmission with the specified Case IH Hy-Tran fluid.

8. 8

   Calibration

   Connect the Case IH Electronic Service Tool (EST) or use the tractor's AFS display to clear the fault codes and perform a transmission/hydraulic pump calibration. This step is critical to resolve the "out of adjustment" (FMI 07) condition and teach the ECU the new pump's mechanical response curve.