Time with no problems will make the light go out or you can hit the reset button on the test unit. If you have an auto parts store nearby, they will very often do this for you.
Check your fluid levels.
Fix the problem causing them to be on.
There is an engine misfire, probably spark plugs issue.
To reset the check engine light unplug the battery for 30 minutes. If the issues still persists the light will still light up when reattached.
Get the computer scanned to see what the problem is.
this is for safety so engine does not get ruined,check oil level!!
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
Disconnect the negative battery terminal for at least 30 seconds.
If the check engine light is illuminated, start with scanning for codes.
Any failure that can increase tailpipe emissions.
If your 2001 Chevy Malibu's check engine light is on and the temperature gauge is not functioning, it could indicate a problem with the engine coolant temperature sensor or the gauge itself. Additionally, the check engine light may signal a variety of issues, from minor to serious. It's advisable to use an OBD-II scanner to retrieve any diagnostic trouble codes, which can help pinpoint the problem. Once you have that information, consider consulting a mechanic for a thorough diagnosis and repair.
The most likely cause o f the check engine light is that the belt was not tightened properly. It may also be that the belt stretched and needs to be retightened.