Massey Ferguson 9133 – TCU: Solenoid Valve 3 Open Circuit

The transmission control module (TCU) has detected an open circuit in the electrical path for Solenoid valve 3. This indicates a break or disconnection in the wiring, a faulty connection at the plug, or a break in the coil winding inside the solenoid itself, which prevents current from flowing and the solenoid from actuating.

• 8650
• 8660
• 8670
• 8680
• 8690

1. 1

   Visually inspect the wiring harness leading to the transmission solenoids for chafing, cuts, or corrosion, and ensure connectors are securely seated and free of dirt or moisture

2. 2

   Record the exact fault code, FMI number, and when the fault appears (e.g., on startup, when shifting)

3. 3

   With the key on and the solenoid commanded on, back-probe the solenoid's electrical connector with a multimeter to check for voltage and a good ground connection (absence of voltage points to a wiring or ECU issue)

4. 4

   Perform a resistance test on the solenoid coil by disconnecting it and measuring across the two pins. A reading of 'OL' (Over Limit) indicates an internal open circuit in the solenoid

1. 1

   Prepare machine for service

   Ensure the tractor is on level ground, engage the parking brake, turn off the engine, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate Solenoid valve 3

   Find the transmission solenoids, typically located in a valve block on the side of the transmission housing. For the MF 8660, some are on the right side of the transmission on the control unit (a valve bank with a nitrogen canister).

3. 3

   Drain transmission fluid

   If necessary based on the solenoid's location, drain the transmission fluid to avoid spills during removal.

4. 4

   Remove the faulty solenoid

   Disconnect the electrical connector, then carefully unbolt and remove the solenoid from the transmission valve body. Be prepared for residual fluid leakage.

5. 5

   Install the new solenoid

   Clean the mounting surface and install the new solenoid with any provided new O-rings or seals. Torque the mounting bolts to manufacturer specifications.

6. 6

   Reassemble and refill fluid

   Reconnect the electrical connector. If fluid was drained, replace the drain plug and refill the transmission with the correct fluid type and amount.

7. 7

   Clear codes and test

   Reconnect the battery, use a diagnostic tool to clear the fault code, and operate the tractor to verify shifting performance.