Product Overview

The Genuine YANMAR Oil Pressure Sensor (Part No. 121252-39450) is a high-precision monitoring component designed to safeguard your diesel engine. This sensor provides real-time data to the engine control unit (ECU) or dashboard gauge, ensuring that the engine operates within safe lubrication parameters.

By detecting drops in oil pressure instantly, this sensor prevents catastrophic engine failure, seized bearings, and overheating. Manufactured to Yanmar’s strict Japanese standards, it offers superior accuracy and resistance to high-vibration environments compared to generic aftermarket alternatives.

Interchangeability & OEM Cross-Reference

This sensor is a standardised part used across a vast global network of equipment manufacturers that rely on Yanmar diesel technology. It is fully interchangeable with or replaces the following OEM part numbers:

• YANMAR: 121252-39450, 12125239450, 114250-39450 (Earlier versions)

• KOMATSU: YM121252-39450

• JOHN DEERE: M801160, AM100611

• TAKEUCHI: 121252-39450

• KOHLER: 25 755 33-S (Oil monitoring component)

• THERMO KING: 44-9111 (Used in specific refrigeration unit blocks)

• MUSTANG / GEHL: 121252-39450

Technical Description

• Thread Specification: Precision-cut 1/8" PT (Pipe Thread) for a leak-proof fit into the engine block.

• Pressure Range: Optimised for low-pressure warning thresholds typical of TNV and TNE series industrial engines.

• Durability: Housed in a corrosion-resistant metallic casing with a high-grade polymer insulator for the electrical terminal.

• Switching Type: Normally Closed (NC) – Grounds the circuit when pressure falls below the safety limit to trigger the warning light/buzzer.

• Vibration Resistance: Internal components are damped to withstand the harmonic frequencies of 2, 3, and 4-cylinder diesel engines.

• Operating Temperature: Rated for continuous exposure to engine oil temperatures exceeding 120°C.

Universal Application Range

The 121252-39450 Sensor is the primary oil pressure monitoring device for almost all modern Yanmar TNE and TNV Series engines.

Compatible Engine Series:

• Yanmar 2-Series: 2TNE68, 2TNV70

• Yanmar 3-Series: 3TNE68, 3TNE74, 3TNE82, 3TNE84, 3TNE88, 3TNV70, 3TNV76, 3TNV82, 3TNV84, 3TNV88

• Yanmar 4-Series: 4TNE84, 4TNE88, 4TNE94, 4TNE98, 4TNV84, 4TNV88, 4TNV94, 4TNV98

• Marine Utility: Yanmar 1GM, 2GM, 3GM, and 3JH auxiliary engines.

Global OEM Trademarks & Equipment:

• Mini-Excavators: Komatsu (PC09, PC10, PC15, PC20, PC27, PC35, PC45, PC55MR), Takeuchi (TB series), Hitachi (Zaxis).

• Compact Tractors: John Deere (2210, 4010, 4110, 4115, 4210, 4310, 4410), Yanmar SA series, Cub Cadet.

• Skid Steers & Loaders: Gehl, Mustang, Wacker Neuson, and ASV Posi-Track.

• Industrial / Cooling: Thermo King and Carrier Transicold units; Generac and Kohler industrial generators.