New Holland NH 2051 – XCM (Multi-function Control Module) or Transmission/Hydraulic Controller: Oil temperature sensor open circuit

This code indicates that the control module has detected an open circuit (infinite resistance or broken connection) in the transmission or hydraulic oil temperature sensor circuit.

• T5
• T7
• T7.220 - T7.270
• TL70A
• TL80A
• TL90A
• TL100A
• TM120 - TM155
• TS90
• TS100
• TS110
• TS115
• 5640
• 6640
• 7740
• 7840
• 8240
• 8340
• T9

1. 1

   Visually inspect the wiring harness leading to the transmission/hydraulic oil temperature sensor for chafing, cuts, or melted sections that would cause an open circuit.

2. 2

   Disconnect the sensor plug and check for pushed-back pins, corrosion, or debris inside the connector.

3. 3

   With the key ON (engine off), use a multimeter to verify that the 5V reference voltage and ground are reaching the sensor connector.

4. 4

   Measure the resistance across the sensor's terminals. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the sensor has failed internally and must be replaced.

1. 1

   Preparation

   Park the tractor on a level surface, turn off the engine, and allow the transmission/hydraulic fluid to cool completely to avoid burns. Relieve any residual system pressure.

2. 2

   Locate the Sensor

   Find the transmission/hydraulic oil temperature sensor on the transmission housing or hydraulic manifold.

3. 3

   Clean the Area

   Thoroughly clean the area around the sensor to prevent dirt or debris from entering the hydraulic/transmission system when the sensor is removed.

4. 4

   Removal

   Disconnect the electrical connector. Use a wrench to carefully unscrew the old sensor from the port. Have a catch pan ready, as a small amount of fluid may leak out.

5. 5

   Installation

   Apply an appropriate hydraulic-safe thread sealant to the threads of the new sensor (if it does not come with pre-applied sealant) to prevent galvanic corrosion and fluid leaks. Thread the new sensor into the port and tighten to OEM specifications.

6. 6

   Reconnection

   Reconnect the electrical harness, ensuring the plug clicks securely into place to withstand engine and transmission vibration.

7. 7

   Testing

   Top off any lost transmission/hydraulic fluid. Start the tractor, check for leaks around the new sensor, and verify that the dashboard temperature gauge reads correctly. Clear the NH 2051 fault code from the XCM/Transmission controller.