It's called "Check engine" light. You need to check why it's on. You can stop by AutoZone and ask them to check it for you. It's free of charge.
A little more information please ( what year , what model of Toyota , what is the engine size )
Try behind the drivers seat and underneath the passenger seat in a little cubby on the floor.
It is normal for a little vibration with the air conditioning on due to the compressor working , fans on , and engine running a little warmer. On at least 92-96 Toyota's the fans automatically come on when the ac is turned on
The thermostat is located underneath the bonnet of the car - in what is called the 'engine bay'. To access the engine bay, pull the bonnet release lever within the car and manually lift the bonnet and secure with the little metal rod thingy. Then - the thermostatica is just donw a bit on the right-hand side of the engine.
there's a little screw right underneath the throttle linkage.
5 Quarts........a little more if you are changing the filter as well.
The interior panel pops off and there is one screw behind the little panel underneath the strap handle.
It is simple. It looks like a little flying saucer and is in the rear of the engine on top near windshield. It was first described to me as one pancake with one pancake underneath & on top of it. There are two hoses that plug into it from the exhaust, and one coming out, and one on bottom (total of 4)
There better be. I just spent a little over $40.00 getting them replaced.
.34 has good response you could even go a little tighter
A 2009 Toyota Rav 4 takes a little over 6 quarts of oil. The recommended weight of the oil to be used is 5w-20.
It is located towards the front of the engine, underneath I believe the intake. It is a little difficult to reach because it is underneath some tubing but you can buy an oil wrench made specifically for Volvo.