Case IH U11 – Electronic Management Unit (EMU): Unable To Calibrate The Suspension

Triggered during the Auto Calibration Procedure (ACP) when the system cannot successfully calibrate the suspended front axle.

• Puma/Mid Range Magnum
• Maxxum
• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225 CVX
• Magnum 305
• Magnum 335

1. 1

   Verify that the lockout switch was not pressed more than 3 times in error by the operator to initiate calibration

2. 2

   Inspect the mechanical components of the front suspension system for physical damage, binding, or lack of lubrication

3. 3

   Check the hydraulic pressure at the suspension accumulators and valve block to ensure adequate pressure to raise and lower the axle

4. 4

   Inspect the front axle potentiometer linkage for damage or disconnection

5. 5

   Check the wiring harness and connector to the potentiometer, and verify the range via the H-Menu/diagnostic screen (range must not be less than 150)

1. 1

   Depressurize the System

   Safety Warning: Do not remove any pipes from the suspension cylinder or valve block unless the system has been completely depressurized. The system remains under pressure even when the tractor engine is off.

2. 2

   Address Hydraulic/Mechanical Faults

   If hydraulic pressure is low, diagnose and repair the suspension valve block or supply pump. If mechanical binding is found, repair or replace the affected suspension linkages.

3. 3

   Adjust or Replace the Potentiometer

   If the mechanicals and hydraulics are fine, the issue is likely the position sensor. Adjust the potentiometer linkage to ensure it sweeps within the correct range.

4. 4

   Install New Sensor

   If the potentiometer is electrically dead, open-circuit, or out of range, remove the retaining nut, circlip, and operating arm, and install a new potentiometer.

5. 5

   Recalibrate

   Once repairs are made, clear the fault codes and re-initiate the Auto Calibration Procedure (ACP) for the front suspension.