The ignition system includes the spark plugs, coil packs, and everything else needed to ignite the air/fuel mixture inside the engine. As you probably guessed, the control module monitors ignition system operation. And it will turn on the check engine light
if it detects a problem
.
Why is my check engine light on without key in ignition?
The check engine light being on without a key in the ignition seems like
an indication of power going to the ECU without the key being on
which sounds like a re-wire situation.
What is the most common problem when the check engine light comes on?
Replacing a faulty oxygen sensor
— a sensor used to optimize a vehicle's fuel-to-air mixture to increase gas mileage and reduce emissions — is the most common cause for a check engine light. With over 400,000 repairs nationwide, oxygen sensor replacements account for 8% of all check engine light repairs.
What usually makes a check engine light come on?
A loose fuel cap
is one of the most common reasons why the check engine light turns on. The cap is a crucial part of a car's fuel delivery system. … If your check engine light turns on immediately after a fill-up, pull over and make sure the cap isn't loose — or still on your car's roof.
Is the check engine light supposed to come on when you turn the key on?
3 Answers. This is normal behavior – When the engine is not running, there is no oil pressure, so
when the ignition is turned on, that light will be on
. As Larry says, this functions as a bulb test so that you know that it is working.
What is wrong when you turn the key and nothing happens?
If nothing happens when you turn the ignition key to the “Start” position, it means that
the starter motor doesn't turn over the engine
. Most commonly this could be caused by a dead battery; read above How to check the battery. … The ignition switch could be bad – it's a common problem.
Will check engine light reset itself?
Your vehicle's check engine light
will will reset by itself once the issue or problem has been repaired
; this is true for most models. … A vehicle cycle is when you start your vehicle and drive it till it warms up, and then you turn the car off.
What does a solid check engine light mean?
If the engine light comes on solid, it may still be a reason for concern, however it doesn't immediately need to strike fear in your heart. A solid Check Engine Light can mean
something like a loose gas cap
, or it can indicate a more in-depth problem like a fuel, timing, or transmission issue.
Is check engine light serious?
The check engine light — more formally known as the malfunction indicator lamp — is a signal from the car's engine computer that something is wrong. … If the light begins flashing, however,
it indicates a more serious problem
, such as a misfire that can quickly overheat the catalytic converter.
Will engine light come on if coolant is low?
Low coolant in the radiator of your car can trigger the
malfunction illumination light
(MIL), also known as the “check engine” light. Low coolant can affect the internal temperature of the engine, which is protected by the antifreeze.
Can AutoZone check engine light?
Does AutoZone Scan Check Engine Lights? AutoZone does. If your light is on, and you are wondering why, head down to your local AutoZone where one
of our store associates can help diagnose the issue through our free Fix Finder service
.
Why wont my car start but I have power?
If your vehicle won't start, it's usually caused by
a dying or dead battery
, loose or corroded connection cables, a bad alternator or an issue with the starter. It can be hard to determine if you're dealing with a battery or an alternator problem.
What are the signs of a bad ignition switch?
- Car Won't Start. If you turn your key and the car attempts to start, but fails, then you might have a broken ignition switch. …
- Key Won't Turn. …
- Car Stalls. …
- No Noise From The Starter. …
- Dashboard Lights Flicker.
Why won't my car start but the radio and lights work?
If the lights and/or the radio come on but the car does not start, you may also
have dirty or corroded battery terminals
. The terminals are what connect the electrical system to the battery. … Attempting to jump start your car can also either confirm or eliminate the battery as the cause of your issue.
Can a blown fuse cause a check engine light?
A check engine light can be caused by a fuse
.
