Case IH 518390-05 - DEC – DEC (Drivetrain Electronic Control): Park brake primary valve solenoid - Current below normal or open circuit

The control module is commanding the parking brake solenoid to energize, but it is detecting little to no electrical current flowing through the circuit. This typically means there is a broken wire, an unplugged connector, a blown fuse, or the internal copper coil of the solenoid itself has broken (open circuit) and has infinite resistance.

• MAGNUM AFS Connect
• Steiger series (400, 540)
• Magnum series (235-340, 310)
• Puma series (165, 180, 195, 210)
• Maxxum series
• Axial-Flow series (5088, 6088, 7088, 5140)

1. 1

   Locate the park brake valve block on the transmission housing and visually inspect the wiring harness leading to the primary valve solenoid for chafed wires, rodent damage, or a disconnected plug.

2. 2

   Unplug the solenoid connector and inspect for pushed-back pins, water intrusion, or green corrosion.

3. 3

   Perform a coil resistance test (Ohm test) using a multimeter across the two pins of the solenoid coil. An 'OL' (Open Loop) or abnormally high resistance reading indicates the coil has failed internally.

4. 4

   If the solenoid tests within normal resistance specifications, test the wiring harness for continuity between the solenoid connector and the DEC/Transmission Controller pins, and verify the ground circuit is intact.

5. 5

   Verify that the transmission control lever park switch and the park relay (often Relay #12 in the cab fuse panel) are functioning and sending the correct voltage to the circuit.

1. 1

   Park the machine on a level surface, turn off the engine, and chock the wheels.

   This is necessary since you will be disabling the parking brake circuit.

2. 2

   Relieve any residual hydraulic pressure in the system if you are replacing the entire valve cartridge.

   If you are only replacing the electrical coil, hydraulic pressure does not need to be relieved.

3. 3

   Disconnect the electrical harness from the park brake primary valve solenoid.

4. 4

   Remove the retaining nut or snap-ring at the top of the solenoid stem.

5. 5

   Slide the faulty electromagnetic coil off the hydraulic valve cartridge.

6. 6

   Slide the new OEM solenoid coil onto the valve stem.

7. 7

   Reinstall and tighten the retaining nut/clip to the specified torque.

   Do not overtighten, or you may crack the plastic coil housing.

8. 8

   Reconnect the electrical harness.

   Ensure the weather-pack seal clicks firmly into place.

9. 9

   Turn the key on, clear the inactive fault codes from the DEC via the cab monitor, and cycle the park brake switch to verify the code does not return.