Case IH 15327 – Steering Controller / Autoguidance ECU: Primary wheel angle sensor (AD1) - signal exceeds calibration limit.

The tractor has articulated or steered beyond its left or right calibrated limit plus an additional 20%. It typically occurs when the mechanical steering angle surpasses the electronic limits set during the last system calibration, or if the sensor itself is sending an out-of-range signal.

• Steiger T4B
• Steiger series (e.g., Steiger 535)
• Puma (115-240)
• Magnum (215-370)
• Maxxum series
• Patriot series (3230, 3320, 4420, etc.)
• G-Series Wheel Loaders

1. 1

   Verify Calibration: Turn the wheels/articulation joint completely to the right and then completely to the left. If the fault code appears during this physical test, the previous calibration was not performed correctly.

2. 2

   Visual Inspection: Inspect the wheel angle sensor (front axle) or articulation cylinder sensor (articulation joint). Check the sensor linkage, short/long arms, and mounting brackets for physical damage, bending, or slipping.

3. 3

   Wiring Check: Inspect the sensor's wiring harness and connectors for corrosion, moisture, or breaks that could cause an erratic signal spike.

1. 1

   Re-calibrate the Sensor

   Before replacing any parts, initiate the wheel angle sensor calibration procedure through the AFS Pro display (or RS1 setup menu).

2. 2

   Turn to Mechanical Stops

   During the calibration prompts, ensure you turn the steering wheel completely to the left and right mechanical stops so the system learns the absolute maximum travel limits.

3. 3

   Test the System

   Save the calibration and turn the wheels lock-to-lock again. If the code does not return, the issue was strictly a calibration error.

4. 4

   Replace the Sensor (if calibration fails)

   If the sensor will not calibrate or the signal remains erratic, power off the machine and install the articulation lock (if working on an articulated tractor).

5. 5

   Remove old sensor

   Disconnect the sensor wiring harness and remove the retaining hardware (O-rings, retaining rings, and slotted screws) holding the sensor body and linkage arm.

6. 6

   Install new sensor

   Install the new wheel angle sensor, reattach the linkage arm, and reconnect the harness.

7. 7

   Final Calibration

   You must perform the wheel angle sensor calibration procedure again after installing a new sensor to establish the new center, left, and right limits.