Case IH FBF – Transmission Control Unit (TCU) / Transmission Controller: PTO Lube Solenoid Over Voltage

The control module has detected an abnormally high voltage on the circuit responsible for the Power Take-Off (PTO) lubrication solenoid. This condition is typically caused by a short to power (+12V) in the wiring harness or an internal short-circuit within the solenoid coil itself.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TM175
• TM190

1. 1

   Check Solenoid Resistance: Turn the ignition switch OFF, disconnect the PTO lube solenoid electrical connector (C519), and measure resistance between terminal 1 and 2. It should be 8 to 11 Ohms. If outside this range, the solenoid is internally shorted.

2. 2

   Check for Short to Power: If solenoid tests OK, disconnect the TCU connectors (C064), turn ignition ON, and probe the PTO lube solenoid harness for +12 volts. If voltage is present, trace and repair the short to power in the wiring harness.

1. 1

   Park and secure tractor

   Park the tractor on a level surface, engage the parking brake, and turn the engine off.

2. 2

   Disconnect battery

   Disconnect the negative battery cable to prevent electrical damage during the repair.

3. 3

   Locate solenoid

   Locate the PTO lube solenoid on the transmission control valve block.

4. 4

   Disconnect electrical connector

   Disconnect the electrical connector from the faulty PTO lube solenoid.

5. 5

   Remove faulty solenoid

   Remove the retaining nut/bolt securing the solenoid coil to the valve stem, and slide the coil off (or unscrew the entire cartridge valve assembly from the block, depending on the exact valve block configuration).

6. 6

   Install new solenoid

   Install the new OEM solenoid valve and tighten it to the manufacturer's specified torque.

7. 7

   Reconnect electrical connector

   Reconnect the electrical connector to the new solenoid.

8. 8

   Reconnect battery

   Reconnect the negative battery cable.

9. 9

   Clear fault code

   Turn the key ON and use the tractor's H-Menu or an electronic service tool to clear the FBF fault code.

10. 10

    Verify repair and calibrate

    Start the engine and verify that the code does not return. A transmission/PTO calibration may be required after replacing a PWM solenoid valve.