New Holland 4174 – HYD: EHR Control No.2 Open Circuit

The fault code indicates an open circuit in the electrical system for the No. 2 rear Electronic Hydraulic Remote (EHR) valve. This suggests a break or disconnection in the wiring, a failed electrical component, or a poor connection, which prevents the control module from energizing the solenoid for that valve. As a result, current cannot flow to or from the solenoid that actuates the second remote hydraulic valve.

• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• TM115
• TM125
• TM135
• TM150
• TM165
• T4000 Series
• TN Series

1. 1

   Visually inspect the wiring harness leading to the No. 2 rear remote valve (typically the second valve from one end of the stack) for chafing, cuts, pinching, or corrosion.

2. 2

   Disconnect the electrical connector at the No. 2 EHR valve solenoid and inspect the pins and sockets for corrosion, dirt, or damage. Ensure it is securely seated when reconnected.

3. 3

   Perform a voltage test: With the key on and the No. 2 remote lever activated, check for voltage at the solenoid connector. No voltage indicates an upstream wiring or control module issue.

4. 4

   Perform a solenoid resistance test: Disconnect the solenoid and measure resistance across its terminals. Infinite resistance (OL) indicates an open circuit within the coil (failed solenoid). A good solenoid typically reads between 20 and 60 ohms (compare to an adjacent functioning EHR solenoid for a baseline).

1. 1

   Prepare machine safely

   Park the tractor on a level surface, turn off the engine, remove the key, and relieve any residual pressure in the hydraulic system.

2. 2

   Access the solenoid

   Locate the No. 2 EHR valve in the rear hydraulic remote valve bank. Remove any protective covers to gain clear access to the electrical connector and the solenoid on the valve body.

3. 3

   Repair wiring or connectors

   If diagnostic tests showed no voltage at the connector, trace the harness back towards the controller. Repair any breaks or corroded sections in the wiring and clean any corroded connector pins.

4. 4

   Replace the solenoid

   If the solenoid is confirmed to be open-circuited (infinite resistance), unscrew the retaining nut holding the coil onto the valve stem. Slide the old solenoid off, install the new solenoid in the correct orientation, and secure it with the retaining nut (do not overtighten). Reconnect the electrical connector.

5. 5

   Clear codes and test operation

   Start the tractor and use the onboard diagnostics or an Electronic Service Tool to clear the stored fault codes. Operate the No. 2 remote hydraulic lever/button to ensure the valve functions correctly and the fault code does not reappear.