When the "check engine" light comes on in your Toyota RAV4, you need to address the underlying problem before fixing the light. The "check engine" light indicates a problem with one of the sensors. You need to figure out which one. To do this, you need a scan tool. Once you've diagnosed and fixed the problem, it's time to reset the "check engine" light. This is the only way to "fix" the light.
Open the fuse panel in your RAV4 by pulling down on the fuse panel cover in the driver's side footwell.
Locate the rectangular plug running from the main wiring harness. It will be to the left of the main fuse panel. This is the on-board diagnostic access port.
Plug the OBD scan tool into the access port and turn on the tool. Then, turn the ignition on, but don't crank the engine. The scan tool will begin to retrieve the diagnostic codes from the RAV4.
Select "stored codes" from the menu options on your scan tool. You'll then need to refer to your RAV4's service manual to translate the numeric engine codes stored on your scan tool.
Press "clear" to clear all engine codes and shut off the "check engine" light on your RAV4 dash.