Case IH 518392-06 - UCM – UCM: Secondary steering bypass solenoid current high

The electrical current flowing to the secondary steering bypass solenoid has exceeded the normal operating threshold, typically pointing to a short circuit in the wiring or a failed internal solenoid coil.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• 325 CVXDrive

1. 1

   Perform a system engagement test by disconnecting the electrical connector from the secondary steering isolator/bypass valve solenoid to manually engage the system, verifying the error displays on the Dash and VT.

2. 2

   Perform a resistance test with the system engaged by turning the steering wheel a 1/4 turn to the right to feel for physical resistance, confirming the hydraulic portion of the secondary steering is functioning.

3. 3

   Use a multimeter to check the wiring harness between the UCM and the secondary steering bypass solenoid for a short to ground or a short to power.

4. 4

   Measure the resistance across the pins of the secondary steering bypass solenoid to check for an abnormally low resistance reading, which indicates a shorted internal coil.

1. 1

   Power down the tractor and locate the secondary steering bypass solenoid on the secondary steering hydraulic valve block.

2. 2

   Disconnect the wiring harness from the solenoid.

3. 3

   Inspect the connector pins for corrosion, melting, or damage.

4. 4

   If the wiring harness is damaged or shorted, repair the affected section of the harness.

   Use appropriate Deutsch sealing plugs and stamped socket contacts.

5. 5

   If the wiring harness tests good, remove the retaining nut/bolt on the secondary steering bypass solenoid and slide the old coil off the valve stem.

   The high current is being caused by a shorted solenoid coil.

6. 6

   Install the new secondary steering bypass solenoid and reconnect the wiring harness.

7. 7

   Connect the Electronic Service Tool (EST) to the diagnostic port to clear the UCM fault codes.

8. 8

   Start the tractor and perform a steering function test to ensure the code does not return.