Case IH 15990 – AST (Advanced Steering) Controller / Steering Valve Controller: AST generic configuration error

Triggers when there is a mismatch in the tractor's software configuration regarding its auto-guidance and steering systems. Specifically, the system detects that at least one of the advanced steering functions (VRS, NAV, or ISOSteering) is configured as 'Present' in the software, but the PVED-CLS controller is configured as 'Not Present'.

• MAXXUM T4E
• VESTRUM CVX
• Case IH Magnum series
• Case IH Puma series
• Case IH Steiger series
• Case IH Optum series
• Case IH Farmall series

1. 1

   Inspect the steering orbital/valve block to verify if the tractor is actually equipped with a Danfoss PVED-CLS electrohydraulic steering valve.

2. 2

   Access the AFS Pro display (e.g., Pro 700 or Pro 1200) or connect the Case IH Electronic Service Tool (EST) to view the current AST configuration. Check the status of VRS, NAV, ISOSteering, and PVED-CLS.

3. 3

   If the PVED-CLS is physically installed but the system thinks it is 'Not Present', check the power, ground, and CAN wiring harness leading to the PVED-CLS actuator for a communication failure or a blown fuse.

1. 1

   Connect diagnostic tool

   Connect the Case IH Electronic Service Tool (EST) laptop to the tractor's diagnostic port, or navigate to the Setup/Diagnostics menu on the in-cab AFS display.

2. 2

   Navigate to configuration

   Navigate to the Advanced Steering (AST) or Autoguidance configuration screen.

3. 3

   Configure PVED-CLS (if equipped)

   If the tractor IS equipped with a PVED-CLS valve: Locate the PVED-CLS setting and change its configuration from 'Not Present' to 'Present'. Note: If it was already set to 'Present' but the code is active, the AST controller has lost communication with the valve. Repair the CAN bus wiring or replace the failed PVED-CLS actuator.

4. 4

   Disable advanced steering (if not equipped)

   If the tractor is NOT equipped with a PVED-CLS valve: You must disable the advanced steering software functions that were accidentally turned on. Set VRS, NAV, and ISOSteering all to 'Not Present'.

5. 5

   Save changes

   Save the configuration changes in the EST or display.

6. 6

   Perform key cycle

   Perform a complete key cycle (turn the tractor off, wait for the ECUs to power down completely, and turn the key back on) to allow the modules to reboot with the new configuration.

7. 7

   Verify repair

   Re-check the active fault code stack to ensure 15990 has cleared.