New Holland 4104 – EHR, AUX, ARU, or TCU: Rear Remote No.1 Under Voltage

The Armrest Control Unit (ARU) has detected an under-voltage condition for the electro-hydraulic remote (EHR) valve circuit #1. This indicates that the solenoid for the first remote valve is not receiving adequate power, which may be due to a power supply issue or a problem with the circuit associated with this remote component. As a safety precaution, the system places remote #1 into a failsafe mode.

• T7.170
• T7.185
• T7.200
• T7.210
• T8.275
• T8.300
• T8.330
• T8.360
• T8.390
• T8.420
• TG245
• T4 Series
• T5 Series

1. 1

   Check battery and charging system (a weak battery or malfunctioning alternator can trigger ghost voltage codes)

2. 2

   Inspect main power and ground connections, especially the main ground strap to the chassis, for looseness or corrosion

3. 3

   Inspect the wiring harness and connectors leading to the No. 1 rear remote valve for chafing, pinching, corrosion, or loose pins

4. 4

   Check for related fault codes, such as 4040 'Supply Voltage too low', which indicates a broader systemic power supply problem rather than an isolated remote issue

1. 1

   Isolate the fault

   Swap the electrical connector from the No. 1 remote valve with an adjacent, functioning remote (e.g., remote #2). If the fault code moves to the other remote, the issue is with the control signal from the armrest or controller. If the 4104 fault remains on remote #1, the problem lies within the valve's solenoid or its dedicated wiring.

2. 2

   Test the solenoid

   Disconnect the electrical connector at the No. 1 remote valve solenoid. Measure the resistance (Ohms) across the two pins. A reading of 'OL' indicates an open circuit, while zero or near-zero ohms indicates a short circuit (both require replacement). Check for a short to ground by measuring resistance from each pin to the valve body or chassis ground; the reading should be 'OL'.

3. 3

   Test voltage at the connector

   With the key on and the remote lever activated, measure the voltage at the harness-side connector for remote #1. If the voltage is below the system's nominal voltage (e.g., below 12V), trace the harness back towards the controller, checking for voltage drops. If the voltage is normal but the solenoid test failed, the solenoid is confirmed faulty.

4. 4

   Replace faulty components

   Replace the solenoid on the valve body if it failed testing. If the entire valve section is determined to be faulty, replace it as an assembly. If diagnostics point to a faulty input device, replace the remote lever/switch in the armrest.

5. 5

   Calibrate the system

   After replacing a remote valve or a primary controller, perform a calibration of the electro-hydraulic remote valves. Initiate this procedure through the tractor's diagnostic menu on the in-cab display to ensure the controller recognizes the new component's operational range.