The 17117506601 and 17137524812 are automotive coolant level sensors for the expansion tank. They monitor the coolant level and provide a signal to the vehicle's monitoring system, enabling alerts when coolant is low. - Function and signal: reliable level sensing and direct signaling to the ECU or gauge. - Why it matters: helps prevent overheating, protects the engine, and supports accurate coolant maintenance. - Compatibility and fit: designed for expansion tanks in many vehicles; confirm compatibility with your car using the part numbers. - Design and build: compact, low profile sensor with automotive grade housing and seals resistant to heat and coolant exposure. - Performance: fast response, stable readings, and resilience to vibration and temperature fluctuations. - Size and fit notes: compact size suits most standard expansion tanks. Practical use scenarios - Routine coolant top-up to verify level in the expansion tank. - Post-service checks after coolant replacement to confirm readings. - Climate-sensitive monitoring in extreme temperatures to track level changes.