Case IH 15229 - AST – Steering Valve Controller: Cut-off solenoid supply duty cycle differs from expected value

The Steering Valve Controller is detecting that the Pulse Width Modulation (PWM) duty cycle being supplied to the steering valve's cut-off solenoid (or the road switch resistor supply) does not match the expected commanded value.

• MAXXUM T4E
• VESTRUM CVX
• Case IH Steiger
• Case IH Optum

1. 1

   Inspect the wiring harness between the Steering Valve Controller and the cut-off solenoid for chafed wires, pinched harnesses, or corrosion inside the connector pins.

2. 2

   Disconnect the cut-off solenoid and measure the resistance across the coil pins with a multimeter to ensure it is not internally shorted or open.

3. 3

   Back-probe the solenoid connector and use a multimeter (set to duty cycle/Hz) or an oscilloscope to monitor the signal from the controller while toggling the auto-guidance system to verify the correct PWM signal.

4. 4

   Ensure the steering valve controller is configured for the correct steering valve type in the software, as incorrect configurations can cause duty cycle mismatches.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground to prevent accidental short circuits.

2. 2

   Locate the Valve

   Locate the main steering valve block (usually located under the cab or near the front articulation joint on Steiger models).

3. 3

   Remove the Solenoid

   Disconnect the electrical connector from the cut-off solenoid. Remove the retaining nut or clip holding the solenoid coil to the valve cartridge stem.

4. 4

   Install the New Solenoid

   Slide the new solenoid coil onto the valve stem and secure it with the retaining nut (do not overtighten, as this can distort the cartridge).

5. 5

   Reconnect

   Plug the electrical connector back in and reconnect the battery.

6. 6

   Clear Codes

   Enter the diagnostic mode on the instrument cluster (Navigate to the R1 module, menu H3, and select the AST system) or use the Case IH Electronic Service Tool (EST) to clear the inactive 15229 fault code.

7. 7

   Calibrate/Test

   Perform a functional test of the auto-guidance system in a safe, open area to ensure the cut-off solenoid engages and disengages properly without throwing the code.