Case IH 518566-03 - ACM – ACM: EHR lever H (Lever 8) voltage high / Internal failure

The Armrest Control Module (ACM) has detected that the signal voltage from the Electro-Hydraulic Remote (EHR) lever H (also designated as Lever 8 in some translated manuals) is above the normal operating range. This typically indicates a short to power (12V) on the signal circuit, an open ground circuit (which causes the signal to pull high), or an internal failure of the potentiometer/switch inside the lever assembly.

• MAGNUM AFS Connect
• Magnum 235-340
• Magnum 380
• Magnum 400
• Steiger 350
• Steiger 370
• Steiger 400
• Steiger 420
• Steiger 450
• Steiger 470
• Steiger 500
• Steiger 540
• Steiger 550
• Steiger 600
• Steiger 620
• Puma
• Maxxum

1. 1

   Visually inspect EHR lever H on the armrest for physical damage, sticking, or binding.

2. 2

   Verify if the EHR lever is properly calibrated by entering the H-Menu / Armrest Calibration menu (an uncalibrated lever can trigger faults).

3. 3

   With the key switch OFF, disconnect the connectors at both the EHR lever and the ACM, then use a multimeter to measure voltage on the signal wire to check for a short to 12 volts.

4. 4

   Perform a continuity test on the wiring harness between the EHR lever and the ACM to check for open circuits. Ensure the ground circuit is intact, as an open ground will cause the potentiometer voltage to read high.

1. 1

   Power Down

   Turn off the key switch and disconnect the battery (or pull the relevant fuse) before servicing electrical components.

2. 2

   Access the Armrest

   Remove the necessary trim panels on the MultiControl Armrest to access the EHR lever block.

3. 3

   Disconnect and Isolate

   Disconnect the wiring harness from EHR lever H.

4. 4

   Test the Harness

   Perform the continuity, short-to-ground, and short-to-power tests outlined above.

5. 5

   Replace the Lever

   If the wiring harness tests good, the fault is internal to the EHR lever assembly. Remove the defective EHR lever from the armrest panel and install the new replacement lever.

6. 6

   Reassemble and Power Up

   Reconnect the wiring harness, reassemble the armrest, and reconnect the battery.

7. 7

   Calibrate the Lever

   You must perform the EHR lever calibration procedure after replacing the lever or the ACM. Turn the key switch to ON, enter the armrest controller calibration main menu (usually within the first 10 seconds of key-on), select the calibration option for the EHR control lever, and follow the display prompts to calibrate the lever's full range of motion.

8. 8

   Clear Codes

   Clear the fault codes and test the hydraulic remote operation to confirm the repair.