The engine light is essentially a warning indicator that something is wrong with the vehicle. Each engine light has it's own meaning and severity.
yes
If the fuel pressure is too low that might cause the service engine light to come on and , since there would not be enough fuel pressure, might also cause a sluggish response. That could be caused by a clogged fuel filter also.
it just means it needs a service take it to the garage they will sort it for you
It sounds like the thermostat is opening up late causing the engine to almost overheat before it opens. Replace the thermostat.
No, the check engine light does not come on because your gas is half way full. The check engine light will come on if there is a problem with the engine.
Well its not good for a fuel injection motor to run out of fuel in the first place. but try disconnecting the positive battery cable for 5 minutes or so and reconnect that should clear the light. make sure you put the right grade of diesel fuel in first. if the light comes back on it may be a different problem or need to be cleared by a code reader. cars run to lean or to rich when check engine lights come on sometimes that may be why the car is sluggish.
No the check engine light will not come on
If an check engine light does not come on it is a good thing. When your check engine light comes on, it means you need service done on your vehicle.
If it has a downstream O2 sensor the check engine light will come on but if it does not the light may not come out. In most instances it will set the check engine light.
Brake light switch has most likely come adrift from it's fitting
No, the check engine light has nothing to do with the oil level in the vehicle. The check engine light will come on when there is a problem with the emission system. The red oil warning light will come on if your vehicle is low on oil.
What engine light? The check engine light should come on when you first start the vehicle and then go out after a few seconds. If it does not the bulb may be burnt out or has been removed.