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Check Engine Light
The check engine light comes on in a car when the engine is experiencing a problem. Ask questions here about your car's check engine light.
7,238 Questions
What if check engine light is flashing?
Flashing engine light on virually any vehicle almost always points to at least 1 cylinder misfiring. It usually is a P0300 - multiple random cylinder misfire code...but I've seen cases with a P0301 through P0308 (cylinder 1-8 misfire...or through 12 if you're lucky enough to have 12 cylinders lol).
What could be the cause of the emission control warning light to come on in a 2002 Ford Taurus SE?
It will be impossible to give you any better than a broad answer here, because there are literally hundreds of possibilities as to why a check engine light(CEL) comes on. The system would have to be scanned to retrieve whatever fail codes there are. Then, we would use a manual (that is literally 3 inches thick)that contains flow charts with pinpoint tests, using a voltmeter, to hand diagnose, and find out what is wrong. This process can take a few minutes, it may take a couple of hours, depending on what is actually wrong.
Now here is the "why" of a CEL: What is actually turning on the CEL is the Powertrain Control Module(PCM), commonly known as the engine control computer. Inside of a PCM there are actually two separate systems. One is control, the other system is diagnostics. PCM diagnostics acts as "big brother," constantly looking over the shoulder of the control side of the PCM. Diagnostics is constantly monitering systems to see if the expected voltages and values are present. For example: If the PCM diagnostics knows that it has been so many minutes since the engine was first started, then the engine temperature should be around 195 degrees. In our senerio, if the engine is still 160 degrees, it sees a problem, and sets the CEL. The technician has to use pinpoint diagnostics to see if we have a stuck thermostat, if the Engine Coolant Temp(ECT) sensor if sending a false signal, if the wiring between the ECT and the PCM is bad, or if the PCM is faulty and interpreting the signal received from the ECT incorrectly. But the PCM is not capable of monitering everything all at once, so it basically goes down a checklist, over and over again, as you are driving down the road. Sometimes a problem can come and go intermittantly, at the right times so as to avoid detection by the PCM. That is why sometimes a CEL doesn't always come on everytime there is a problem. Sometimes you can unplug a sensor even while the car is running, and it takes a while for the CEL to come on, just because the PCM diagnostics hasen't gotten back around to looking at that area yet.
Our senerio only talked about one area that a PCM moniters. There are dozens of sub-systems that the PCM looks at, and dozens of possible failures within each of those sub-systems, that could cause a CEL.
What would cause a cylinder misfire and is it serious?
Misfires can be caused by many things. The most common causes are ignition system faults, fuel metering problems, and mechanical engine problems.
A misfire caused by an ignition system fault or an overly rich fuel condition can lead to severe engine damage (requiring rebuild or replacement of the engine) as well as (less costly) damage to oxygen sensors, catalytic converters, exhaust system components, and carpeting.
Misfires, regardless of cause, can damage automatic transmissions and powertrain mounts.
What is a secondary air injection system fault?
Secondary Air Injection is an emissions system that pumps clean air into the exhaust of a vehicle to help lower emissions. It wont effect your fuel mileage or m ake your car blow up. It WILL turn the service engine soon light on. Most parts stores can clear the code from the system, but it is going to come back on. You can pay a dealer to try to fix it, but most likely they will take your money.
How do you get the check engine light to go off?
The corect and only real way:
Have the car scanned, this will tell you what is wrong.
Repair the fault.
Have the car scanned and re-set.
If you re-set the system without repair it will just come back on.
How do you reset the check engine light on a Toyota Camry?
Sorry, it has to be done by the dealer or you need to buy the gauge yourself.
My Suggestion: Remove battery terminal (pos or neg, doesnt matter) leave for 10 min, reconnect, see if gone
How to check malfunction codes on a 1991 park ave?
You will need an OBD I scan tool, they are fairly inexpensive for this car, as you can read the trouble codes by the flash of the "Service Engine Soon" light. Most likey you have a code for the cam sensor, as every TPI 3800 gives this code eventually
It's not the valve. I've never worked on an acura. but it's not the valve. they rarely short out. check the passages, and the vacum pump. hopefully someone with acura experience comes along. good luck.
Ok this guy is a clown. I have never worked on an acura either but it may verry well be that the egr valve is coverd in carbon. The carbon is easy to clean with a wire brush if you remove the valve.The main cause of malfunction in an egr valve is the carbon build up leaving it stuck open or closed! Simple huh?
i have a 99tl that had the same problem. simply remove the intake and clean the carbon from the passages to egr. it not difficult, it took about 15 mins and have not had trouble since, good luck!
Absolutely right! I had a problem where when I drive at a constant speed of 45mph or higher, my '99 Acura TL would behave very weirdly. The engine didn't turn off but even though the car is in DRIVE but still behaved like it was in NEUTRAL, and then it will kick back in and start working again. This happened a lot of times then the check engine light came on. I received the P0401 error code. I bought a new EGR valve from Autozone and replaced it. Works great. However, I do hear a little bit louder noise when the engine starts and I take off, but the Autozone guy told me that it is because there is a lot more air passing through, since the old valve was clogged up.
It is fairly easy and quick to change. I love the performance now!
How do you reset service engine soon code on 2001 eldorado Cadillac?
DISSCONECT YOUR BATT FOR 10 seconds...........there you have it
Your check engine light is on on your 2005 Chevy Tahoe what does that mean?
It means there is a problem in the emission system are transmission.
Need to have engine scaned with a engine scanner. Some parts stores will do that for free.
How much will it cost to fix a cylinder misfire on a 97 Mitsubishi Mirage?
Have you checked the spark plug wire for that cylinder,??????????
Will valve adjustment cause a misfire in a cylinder?
If the valves were adjusted incorrectly, yes it can cause a miss. It can also burn a valve if they are adjusted too tightly.
Trouble code P1698 means: No CCD Messages Received From The TCM
CCD is the comunication system Chrysler uses between computers.
How do you reset check engine light on a Nissan?
There are several methods (each resulting in temporarily "disabling" the Diagnostic Trouble Code, known as DTC). Usually, you can disconnect the battery NEG terminal for several minutes (to be sure). You might succeed in resetting the computer by cycling the ignition switch (on, off, on, off, on, off), each time waiting for 3-5 seconds in each position. There are a variety of methods (depending on make, model, year) which may, or may not, be successful. What many "mechanics" do not know is what series of electronic events take place when they connect a diagnostic tool to any given vehicle. When said mechanic chooses to "erase" (using a scan tool) the DTC from memory, they are only turning the light off, and not fixing the problem. Once a DTC has been set, that code remains until said problem is remedied. Oftentimes, a "Service Engine Soon" lamp will illuminate when a vehicle is in need of routine maintenance, a "hiccup" due to bad gas, a leaking vac. line, etc. "Check Engine" lamps require more serious attention. There are many varied techniques for PROPERLY resetting the PCM/ECM parameters (back to factory specs). Many require a series of start/stop driving conditions, such as: accelerating from 0-60 and maintaining speed for 5 miles, decreasing speed to 40MPH... and maintaining said speed for 2 miles, stopping car to idle for 1 min, Etc. You might try a "quick flash" by disconnecting both cables from the battery. Then, clamp both NEG and POS cables together...making sure that you do not allow this connection to make contact with the battery ( or any other positive power source). Allow this connection to rest for about 10 minutes. Keep in mind that computers are very sensitive, and are subject to damage... by even the slightest of power surges...or inadvertent contact with a power source. Automobile computers ground POSITIVE, not NEGATIVE. So, what you are doing when you connect the two cables together is drawing down any unwanted energy which might be stored in the computer/ICM/ECM/PCM... Reconnect the cables to the battery (after 10 min.). Then, to be certain that the previous codes are not "ghosting", drive the car for a minimum of 20 miles (preferably 60). If the codes were properly (and permanently) removed, the DTC lamp will not light again. Good luck.
What does it mean when a 1999 Ford Taurus wagon check engine light stays on?
It means the ECU has detected a problem with the emissions system on the vehicle. Have the ECU scanned with an OBD2 scan tool to retrieve the code that has been set. This code will help you find the problem.
How do you remove the service engine light on a chevrelot?
After repairing the cause of the code, you can clear it with a scan tool.
What causes check engine light to come on and stop the car from starting?
The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to a parts store or a shop that has an OBD2 scanner, or for 1995 and earlier models, an OBD1 scanner, While a scanner will not give you the magic answer, it will give you a code that narrows down the problem area.
The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to a parts store or a shop that has an OBD2 scanner, or for 1995 and earlier models, an OBD1 scanner, While a scanner will not give you the magic answer, it will give you a code that narrows down the problem area.
What is wrong when all warning lights come on in a 1988 Mazda 626?
All the warning lights are supposed to turn on for a few seconds as a "bulb check" when turning the key to start the car. Do the lights stay on after the car has started? If so, you could have anything from a faulty ground to a damaged computer.
What is wrong if your check engine lihgt starts flashing on your 97 Mazda proteze?
If your check engine light is flashing an engine cylinder misfire has been detected
How do you check engine codes on a 1995 Sable - Taurus without using a scanner?
There are methods of doing this - and I've tried them a couple of times with some of my older Tauruii/Sables.
Here's my opinion: don't waste your time - it's so unreliable and vague.
I'm 99+% sure the 95 uses the current diagnostics system, OnBoard Diagnostic II (OBD II) so any local auto parts store that offers free code scanning / reading can do that on the 1995's.
See "Related Questions" below for more
Take to local shop have them Run a ABS scan they can tell you why. Cost is approx $80.00
What to check code P0420 says catalyst efficiency below threshold bank1?
The PCM copares switch rates between the front O2 sensors and the downstream catalyst moniters. The catylist moniters are often mistaken as O2 sensors, and they are, but that is not their job, or what they are called. By comparing the switch rates between the front (before cat) and rear (downstream of cat) the PCM knows if the cat is affecting the exaust, and how much it is affecting the exaust. If it sees little or no effect o the exaust gases that have passed through the cat, then it decides that the cat is not working anymore, ad sets a P0420, or a P0430, depending on which bank it is. To check this yourself, you will need to bring up data stream on your scanner, watch the upstream and downstream O2 parameters and see if they are following each other closely. If the cat is working right, you should see a fairly rapid switch rate, probably 5 or 6 times a minute on the front O2, but almost a flat line just above .5 volts on the rear. If the rear is switching often you proabably need a catalytic converter.
check for damaged parts loose connections oxygen sensors and catalyst convertor
If everything looks intact and that is your only code, you probably have a failing catalytic converter.
What is a Warm up catalyst below threshold part look like?
what is a warm up catalyst below threshold parts look like? and It is for a car mit Elcipes.
How do you reset the check engine light on a 2006 Chevy suburban?
It requires an engine scanner to do that.
There is no information for break one light. If you have one brake light it means you have one that is burnt out. You will need to get that replaced because both must be in working order.
