Case IH U03 – Chassis Control Module (CCM) or Suspension Controller: Front Axle Potentiometer Short Circuit - Auto Calibration Procedure Will Not Work

The position sensor (potentiometer) responsible for measuring the front axle's suspension articulation has suffered a short circuit. Because the system cannot accurately read the axle's height or position, the tractor's Auto Calibration Procedure (ACP) for the front suspension is disabled and will fail to run.

• Puma/Mid Range Magnum
• MXM
• Puma Series
• Magnum Series
• MXM Series
• Maxxum
• Steiger
• MX/TG Series
• Farmall

1. 1

   Inspect the wiring harness leading to the front axle potentiometer for any physical damage, rubbing, or short circuits to power/ground.

2. 2

   Test the potentiometer's connector to verify if the signal ground is an open circuit.

3. 3

   Check the physical installation and linkage of the position sensor to ensure it hasn't been damaged by field debris or over-extension.

1. 1

   Power down the tractor and locate the front axle potentiometer on the front axle suspension assembly.

2. 2

   Disconnect the sensor's wiring harness.

3. 3

   Using a multimeter, verify the integrity of the wiring harness back to the ECU (checking for shorts) and ensure the ground circuit is not open.

4. 4

   Remove the faulty potentiometer.

   If the wiring harness and ground signal are intact, the short circuit is internal to the sensor.

5. 5

   Install the new front axle potentiometer and securely reconnect the wiring harness.

6. 6

   Power on the tractor and initiate the Auto Calibration Procedure (ACP) for the front suspension to calibrate the new sensor's minimum and maximum thresholds.