Case IH 15231 - AST – MTA CCM & APH / AST: Cut-off solenoid supply low resistance or short to ground

This code indicates an electrical fault in the supply circuit for the steering cut-off solenoid, which is a critical safety and operational component of the tractor's automated steering system. The system has detected that the resistance in the solenoid's circuit is abnormally low, or the power supply wire has shorted directly to the chassis ground.

• MAXXUM T4E
• VESTRUM CVX
• Stage V MR
• Farmall series (40-45-50)
• Puma
• Maxxum
• Magnum

1. 1

   Access On-Board Diagnostics (R1 module, menu H3, AST system) to view active fault states.

2. 2

   Inspect the wiring harness running from the CCM/AST module to the steering valve's cut-off solenoid for chafed insulation, pinched wires, or melted areas that could cause a short to ground.

3. 3

   Disconnect the electrical connector at the cut-off solenoid and use a multimeter to measure the resistance across the solenoid coil pins to check for an internal short.

4. 4

   Test the supply wire from the ECU harness connector to the solenoid connector for continuity to ground.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent further electrical damage.

2. 2

   Locate the Valve

   Locate the hydrostatic steering valve assembly, which houses the AST cut-off solenoid.

3. 3

   Disconnect

   Unplug the electrical connector from the cut-off solenoid.

4. 4

   Harness Repair (If Applicable)

   If the diagnostic checks revealed a short in the wiring, repair the damaged section of the harness and secure it away from pinch points.

5. 5

   Solenoid Replacement (If Applicable)

   If the solenoid coil failed the resistance test, remove the retaining nut/fastener holding the solenoid coil to the valve stem. Slide the old coil off and install the new replacement coil.

6. 6

   Reassembly

   Reconnect the electrical connector and reconnect the battery.

7. 7

   Calibration

   Clear the fault codes via the instrument cluster or a compatible diagnostic tool. Perform a steering calibration in the AST system to ensure proper synchronization between the steering valve main and safety controllers.