418-18-31501 —  Komatsu Speed Sensor for WA250-5 Series Wheel Loaders. This component serves a critical function within the transmission and hydraulic drive systems, providing essential speed feedback and status monitoring to ensure the TCU (Transmission Control Unit) accurately acquires vehicle travel speed and gear position signals.

I. Core Positioning & Technical Specifications

Table

Parameter Details

Part Number 418-18-31501 (Related Variants: 418-18-31502/3; compatibility may vary slightly)

System Affiliation WA250-5 Transmission / TCU; Drivetrain Control System

Signal Type Pulse / Speed Signal (Non-analog pressure signal); used for speed feedback

Electrical Specs Multi-pin waterproof connector; compatible with 12V/24V heavy-duty equipment electrical systems

Protection Rating IP67; Vibration-resistant, Oil-resistant, High-temperature tolerant (-40°C to 125°C)

Core Function Transmits speed signals to the TCU; facilitates gear-shifting control and instrument panel display

II. Compatible Models

Primary Compatibility: Komatsu WA250-5 Full Series (including extended models: WA250-5L/PT/PTL)

Cross-Compatibility: Select models on the same platform (WA150-5, WA200-5, WA320-5); verification of wiring harness and mounting position is required.

III. Fault Symptoms & Rapid Diagnosis

Typical Symptoms:

Speedometer on the instrument panel shows no reading or displays abnormal signals

Transmission exhibits shifting shock/jerking, gets stuck in a specific gear (gear lock), or fails to engage any gear

Automatic deceleration or stalling occurs while driving; TCU logs a fault code indicating a speed sensor failure

Troubleshooting Steps:

Code Reading: Use a diagnostic tool to read TCU fault codes and confirm if the error points to this specific sensor

Resistance Measurement: With power disconnected, measure the resistance across the connector pins (Reference Value: 80–120Ω)

Replacement Test: Replace the sensor with a known-good unit of the same model to rule out potential faults in the wiring harness or ECU