What does it mean when your check engine light comes on and then goes off?
In a perfect world, you’ll find that a check engine light on and off intermittently is being caused by a loose gas cap. But many times, a check engine light will be caused by something other than a loose gas cap. It can, for example, be caused by a faulty oxygen sensor.
Can your engine light came on for no reason?
The check engine light can come on for many reasons. For example, something as simple as a loose gas cap can trigger the warning. And major problems, such as failed internal engine components, can turn on the light, as well.
How many miles before a check engine light is turned on?
For example, the gas tank has to be at a level of 1/4 to 3/4 filled before it can, say, check the seal of the gas cap. So, you might drive 100 or 200 miles before a check gets done. Then, if a problem is found, the check engine light gets turned on, and a trouble code gets set in the engine computer.
Why does my check engine light keep coming on and off?
But, there are other possible causes of intermittent illumination of the Check Engine Light such as failures in engine sensors, intermittent misfires, and faults with sticky or stuck valves such as in the EGR (exhaust gas recirculation) system or the EVAP system.
Why is the Check Engine light coming out on my 05 Tundra?
My 05 Toy Tundra has been a joy for 90,000 miles. This is the only real problem: Thinking the seal on the gas cap was causing the check engine light to come on, I cleaned the rubber cap seal and the metal receiver with Armor-All. After a few start-stop cycles, the light went out, so I bought a new cap. A couple months later, the light returns.
How often does the engine computer need to check the gas tank?
For the EVAP (fuel evaporation control system) sensors and circuits, it might be several vehicle trips before the required conditions are present that the engine computer is allowed to check those sensors and systems. For example, the gas tank has to be at a level of 1/4 to 3/4 filled before it can, say, check the seal of the gas cap.
