Case IH U02 – Suspension Control Module or Transmission/Chassis Controller: Front Axle Potentiometer Threshold Is Higher Than The Set Limit

The position sensor (potentiometer) monitoring the front axle suspension is returning a voltage or digital value that exceeds the maximum allowable calibrated limit, preventing the Auto Calibration Procedure (ACP) from working.

• Puma/Mid Range Magnum
• MXM
• Case IH Maxxum (MXM Series)
• Case IH Puma Series
• Case IH MX Series
• Case IH Steiger Series
• Case IH Magnum Series
• Case IH Optum Series

1. 1

   Enter the tractor's diagnostic/calibration mode and observe the live potentiometer reading (value > 970 or > 4840 indicates out of range)

2. 2

   Inspect the physical installation and mechanical linkage of the front axle potentiometer for a bent bracket or seized linkage that could push the sensor past its limit

3. 3

   Disconnect the sensor and inspect the wiring harness to verify proper reference power and ground

4. 4

   Ensure the signal wire is not shorted to a power source, which would cause an artificially high reading

1. 1

   Secure the Machine

   Park the tractor on a level surface, lower any implements, and engage the parking brake.

2. 2

   Inspect and Adjust Linkage

   Locate the front axle suspension potentiometer. Inspect the linkage rods and pivot points. If the linkage is damaged or misadjusted, repair it and re-check the sensor values.

3. 3

   Replace the Sensor

   If the wiring harness tests good (no shorts to power, good ground) and the linkage is intact, the potentiometer itself has failed internally. Remove the mounting bolts and disconnect the linkage to remove the faulty sensor.

4. 4

   Install New Part

   Mount the new potentiometer, reconnect the mechanical linkage, and plug in the electrical harness.

5. 5

   Perform Auto Calibration

   Run the front axle Auto Calibration Procedure (ACP) via the tractor's H-Menu or diagnostic interface to teach the control module the new sensor's minimum and maximum travel limits.