New Holland ARMRE 18026 – Armrest Module (ARU / ARM / ATC): Rear hitch slip control potentiometer - voltage too high

This code indicates that the signal voltage returning from the rear hitch slip control potentiometer (a dial located on the operator's armrest) has exceeded the maximum expected threshold (typically above 4.5V or 5.0V). This condition is almost always caused by a short to power on the signal circuit, an open ground wire on the potentiometer circuit, or an internal failure of the potentiometer itself.

• New Holland T6 Series (T6.140 - T6.175)
• New Holland T7 Series (T7.170 - T7.270)
• New Holland T8 Series
• New Holland T9 Series
• New Holland T6000/T7000 series

1. 1

   Visual Inspection: Remove the armrest control panel cover and inspect the wiring harness leading to the slip control potentiometer. Look for pinched wires, chafing, or damaged insulation that could cause a short to power.

2. 2

   Connector Check: Disconnect the potentiometer and inspect the pins for corrosion, moisture, or pushed-out terminals.

3. 3

   Circuit Testing (Multimeter): Check the ground circuit to the potentiometer for continuity. An open ground will cause the signal voltage to default high.

4. 4

   Circuit Testing (Multimeter): Check the signal wire for a short to a 12V or 5V power source.

5. 5

   Component Testing: If the wiring harness (power, ground, and signal continuity) tests good, the potentiometer has likely failed internally and is sending a full-voltage signal back to the Armrest Module.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Armrest

   Carefully remove the retaining screws on the operator's armrest console to lift the control panel faceplate.

3. 3

   Remove the Faulty Component

   Locate the rear hitch slip control potentiometer (usually grouped with the draft sensitivity and drop rate control knobs). Disconnect its electrical connector.

4. 4

   Swap/Install

   Unbolt or unclip the faulty potentiometer from the armrest frame and install the replacement part.

5. 5

   Reassembly

   Reconnect the electrical harness, ensuring the connector clicks securely into place. Reinstall the armrest faceplate.

6. 6

   Clear Codes & Calibrate

   Reconnect the battery and turn the key to the ON position. Use the tractor's instrument cluster diagnostic menu (H menu) or a CNH Electronic Service Tool (EST) to clear the inactive 18026 fault code. Depending on the exact model, you may need to perform a brief potentiometer calibration via the tractor's display to teach the Armrest Module the new minimum and maximum voltage values.