Understanding Vehicle Fluids for the Code de la Route\n\nManaging your vehicle's fluids is a core requirement of the French driving theory exam (ETG). Under the Code de la Route, a driver is responsible for the mechanical state of their vehicle. Regularly inspecting fluids prevents sudden mechanical failures, reduces environmental impact, and ensures your vehicle remains safe for all road users.\n\n## The Five Vital Liquids You Must Monitor\n\nTo pass your theory test and drive safely, you must know the role, location, and maintenance rules for five primary fluids:\n\n1. Engine Oil: Lubricates moving parts, reduces friction, and helps cool the motor. Its level must be checked using the dipstick, remaining between the minimum and maximum indicators.\n\n2. Engine Coolant: Prevents the engine from overheating in summer and freezing in winter. It circulates in a closed loop and must only be opened when the engine is completely cold to avoid explosive, boiling liquid escaping.\n\n3. Brake Fluid: Transmits hydraulic pressure to stop the vehicle. A drop in this fluid directly threatens your ability to stop and requires immediate inspection.\n\n4. Power Steering Fluid: Assists in steering control, making turning the steering wheel smooth and effortless.\n\n5. Windshield Washer Fluid: Essential for maintaining clean glass and visibility. It is the only fluid that does not have a strict maximum limit and can be filled to the top.\n\n## Safe Checking Procedures: Flat Ground and Cold Engine\n\nTheory exam questions frequently test your knowledge of how to perform fluid checks. There are two golden rules for checking engine oil, coolant, and brake fluid: the car must be parked on a level, flat surface, and the engine must be completely cold. Checking levels on a slope or while the engine is hot will lead to incorrect readings, potentially causing you to overfill or underfill reservoirs, which can damage the engine.\n\n## Deciphering Dashboard Warning Lights\n\nOn the French driving exam, you must instantly recognize what dashboard lights indicate. An amber (yellow) light acts as a warning, signaling that a fluid level is low or a system requires attention soon. A red light represents an immediate danger. If a red light for oil pressure or brake fluid illuminates while driving, you must find a safe spot to pull over, shut off the engine, and call for roadside assistance immediately.