Case IH 18046 – Armrest Controller (ARU - Armrest Control Unit): EHR (remote valve) float control switch error

This code indicates an electrical fault—such as an open circuit, short circuit, or out-of-range voltage—originating from the switch that commands the Electronic Hitch/Hydraulic Remote (EHR) valve into the "float" position. When this code is thrown, the affected remote valve will typically lock up and become inoperable until the tractor is restarted.

• Magnum
• Steiger T4B
• Case IH Magnum Series
• Case IH Steiger Series
• Case IH Puma Series

1. 1

   Bypass Test: Assign the hydraulic implement to a different remote valve (e.g., move from SCV 1 to SCV 2) to see if the issue is isolated to a specific physical switch or a specific valve block at the rear of the tractor.

2. 2

   H9 Voltmeter Diagnostic Screen: Access the 'H9 - VOLTMETER' menu through the tractor's display or the Electronic Service Tool (EST) to verify live voltage and operation of the armrest potentiometers and EHR switches. Erratic jumps indicate a failing switch contact.

3. 3

   Wiring Harness Inspection: Inspect the wiring harness connecting the armrest EHR switches and the fender-mounted PTO/EHR switches. Look for pinched wires or corroded connectors, specifically the 6-cavity female connectors.

4. 4

   Pilot Head Check: If the armrest switch tests perfectly, check the remote valve's 'pilot head' at the rear of the tractor. Pilot head failures frequently trigger switch/position codes because the valve cannot physically reach the commanded float or neutral state.

1. 1

   Disconnect battery

   If replacing the Armrest/Fender EHR Switch: Disconnect the tractor's battery to prevent shorting sensitive armrest electronics.

2. 2

   Remove trim panels

   Remove the trim panels on the armrest console or the rear fender (depending on which switch is throwing the fault).

3. 3

   Disconnect harness

   Disconnect the wiring harness connector from the faulty EHR switch.

4. 4

   Install new switch

   Unclip or unscrew the switch from the bezel and install the new switch.

5. 5

   Reconnect and clear codes

   Reconnect the harness, restore battery power, and use the EST or in-cab display to clear the fault codes.

6. 6

   Clean valve area

   If replacing the Remote Valve Pilot Head (Common Dealer Fix): Thoroughly clean the area around the affected rear remote valve to prevent dirt from entering the hydraulic system.

7. 7

   Relieve hydraulic pressure

   Relieve all hydraulic pressure from the system.

8. 8

   Disconnect pilot head harness

   Disconnect the electrical harness from the pilot head assembly on the affected valve section.

9. 9

   Remove mounting screws

   Remove the mounting screws holding the pilot head to the main valve body.

10. 10

    Remove old pilot head

    Remove the old pilot head. Note: Save and inspect the O-rings underneath the cover if the new part does not include them.

11. 11

    Install new pilot head

    Lubricate the new pilot head O-rings with clean hydraulic oil and install the new pilot head assembly.

12. 12

    Torque screws

    Torque the valve spool cover screws to the OEM specification (typically 27-31 Nm or 19-22 lb-ft).

13. 13

    Reconnect and test

    Reconnect the electrical harness, start the tractor, and test the remote valve for proper float engagement.