What does the DEF warning light mean?

[SanCamilla]

The DEF warning light refers to the indicator light for the vehicle's auxiliary water tank. When this light is illuminated, it indicates that the auxiliary water tank is low on water, and it needs to be refilled immediately to resolve the issue. The reasons for the DEF warning light coming on are: 1. Engine temperature is too high, triggering an alarm. 2. The water temperature sensor is damaged. 3. Insufficient antifreeze. Types of indicator lights: 1. Oil pressure indicator: This light is used to display the oil pressure status in the engine. 2. Water temperature indicator: Primarily shows the temperature of the coolant in the engine. 3. Handbrake indicator: This light automatically turns on when the handbrake is engaged. 4. Battery indicator: This light also illuminates during vehicle self-check and turns off after startup. If it remains lit after startup, the battery may need replacement. 5. ABS indicator: If the ABS light does not flash when starting the engine or remains lit after startup, it indicates an ABS malfunction.