Case IH 18252 - ACML – ACML: EHR Encoder Circuit Issue

Indicates an issue with the EHR (Electro-Hydraulic Remote) Encoder circuit, which is a rotary potentiometer knob on the armrest used to adjust settings. The fault likely indicates an out-of-range voltage, open circuit, or position error from this specific potentiometer.

• MAXXUM T4E
• VESTRUM CVX
• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 340
• Steiger 540

1. 1

   Check the Armrest Control Module (ACML) for general communication loss (related codes like 2818 indicate a loss of communication with the ACM)

2. 2

   Inspect the wiring harness connecting the EHR Encoder potentiometer to the ACML for open circuits, shorts, or pinched wires inside the armrest

3. 3

   Test the potentiometer voltage for a smooth voltage sweep when turning the knob (operates on a 5V reference circuit, rated for 30mA, 150mW)

4. 4

   Check for physical damage, debris, or sticking of the EHR Encoder knob on the armrest control panel

1. 1

   Disconnect battery

   Disconnect battery power to the tractor to prevent short circuits to the ACML.

2. 2

   Remove console cover

   Remove the right-hand armrest control console cover to access the internal ACML components and wiring.

3. 3

   Locate potentiometer

   Locate the faulty EHR Encoder potentiometer on the control board.

4. 4

   Disconnect wiring

   Disconnect the wiring harness connector from the potentiometer.

5. 5

   Remove knob

   Pull off the external knob from the encoder shaft.

6. 6

   Remove potentiometer

   Unbolt or unclip the potentiometer from the armrest panel mounting bracket.

7. 7

   Install new potentiometer

   Install the new potentiometer and secure it to the panel.

8. 8

   Reattach components

   Reattach the external knob and reconnect the wiring harness.

9. 9

   Reassemble and clear codes

   Reassemble the armrest console, restore battery power, and clear the fault codes using a diagnostic tool or the tractor's IntelliView display monitor.