161-1704 (1611704) Caterpillar Oil Pressure Sensor: Provides a continuous analog oil pressure signal to the engine ECU for pressure monitoring and protection. I. Core Basic Information

Part Number: 161-1704 (Old No.: 1611704)

Type: Piezoresistive / Capacitive Pressure Sensor (Active, 3-pin)

Brand: Caterpillar

Function: Real-time monitoring of engine oil pressure; outputs an analog voltage signal to the ECU for dashboard display, pressure alarms, and engine protection.

II. Key Technical Specifications

Electrical: 3-pin waterproof connector; compatible with both 12V and 24V systems.

Thread Specification: M16×1.5 (Metric Fine Thread)

Pressure Range: 0–10 bar (0–145 psi) (Common range for engine oil pressure)

Operating Temperature: -40°C to +125°C

Output Signal: 0.5–4.5V (Varies linearly with pressure)

Material: Stainless steel probe + high-temperature-resistant seal; vibration-resistant and oil-resistant.

III. Main Compatible Engines

C7, C9, C10, C12, C15, C18

3508B, 3512B, 3516B, 3516C, and other large-displacement engines.

IV. Main Compatible Equipment

Excavators (Most Common)

324D, 325D, 328D, 329D, 330C, 330D, 336D, M325D MH

Loaders / Dozers / Motor Graders

950H, 962H, 966H, 980H; D6R, D7R; 12K, 140K, 160K

Other Equipment

Skidders: 525C/535C/545C; Scrapers: 637G; Compactors: 815F II; Cold Planers: PM-102

V. Alternative Models

210-1747 (2101747) (Direct replacement; identical specifications) 194-6725, 224-4536, 237-3071 (Common OEM Replacement Numbers)

VII. Common Faults and Replacement Guidelines

**Fault Symptoms**

No oil pressure display, or abnormal display (reading too high, too low, or fluctuating)

ECU reports an oil pressure sensor fault (e.g., codes P0520, P0521, P0522)

Engine triggers a low oil pressure alarm, or automatically enters speed-limiting/shutdown mode

**Replacement Guidelines**

Perform removal and installation only after the engine has been shut down and allowed to cool, to prevent burns and oil leaks

Clean the installation port and apply a small amount of high-temperature-resistant sealant

Tighten to the specified torque (approximately 25–30 N·m)

After installation, test-run the engine to verify that the pressure display and alarm functions are operating normally