The green light on the dash of a Jeep Grand Cherokee is an indicator that the engine is in good condition. This light, which can be found near the speedometer and tachometer, is also known as a Check Engine Light. When this light turns on, it means that there are some issues with your car's systems or components, such as spark plugs, oxygen sensors, fuel injectors or emission control systems. If you see this light while driving your vehicle it is important to take your Jeep Grand Cherokee to a qualified mechanic for inspection and repair if necessary. In most cases they will be able to quickly diagnose and fix any problems associated with this warning system so you can continue driving safely again.