Case IH A-G-906 - Display – Steering Controller: Steering Controller Safe State

The steering controller has detected a critical fault (such as a sensor signal out of range, CAN bus communication loss, or an internal hardware error) and has forced the system into a 'Safe State' (fail-safe mode). In this state, the automated electro-hydraulic steering is completely disengaged, and the tractor defaults to manual hydraulic steering only.

• MAGNUM AFS Connect
• STEIGER AFS Connect
• Magnum AFS Connect Series
• Magnum 400 AFS Connect
• Steiger
• Quadtrac
• Rowtrac
• Puma

1. 1

   Check for associated fault codes (such as A-G-905, A-G-716, or A-G-630) that pinpoint the exact failure

2. 2

   Inspect the Wheel Angle Sensor (WAS) for physical damage, loose mounting hardware, and verify linkage rods are tight

3. 3

   Inspect the wiring harness connecting the Wheel Angle Sensor to the Steering Controller for open circuits, shorts to ground, or shorts to power

4. 4

   Verify CAN bus communication lines between the AFS display, the Steering Controller, and the tractor's main ECU are intact and securely connected

5. 5

   Verify the tractor's hydraulic fluid level is correct and check the steering valve/actuator for any oil leaks

1. 1

   Resolve Physical/Electrical Issues

   Repair or replace any damaged wiring harnesses, connectors, or the Wheel Angle Sensor if it failed the diagnostic checks.

2. 2

   Clear Fault Codes

   Cycle the key power and use the AFS Connect display (or a diagnostic tool like Jaltest/CNH EST) to clear the active A-G-906 fault.

3. 3

   Recalibrate the Steering System

   Perform the built-in display calibrations: Run the Wheel Angle Sensor Calibration (Code A-G-700 will display) and the Steering Deadband Calibration (Code A-G-705 will display).

4. 4

   Test Manual and Auto Steering

   Lift the steered axle if necessary, or test in a safe field environment. Turn the steering wheel lock-to-lock manually to ensure there is no mechanical binding, then engage the auto-guidance to verify the safe state does not return.

5. 5

   Replace Controller (If Necessary)

   If the wiring and sensors are perfectly intact but the A-G-906 code immediately returns (or communication codes like A-G-630 persist), the Steering Controller itself has suffered an internal hardware failure and must be replaced and reprogrammed.