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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
The emissions part of your state inspection failed What is the most common cause?
Most common? Probably the oxygen sensor.
But that's like asking your doctor, "what's the most common cause of a bellyache?" Usually it's gas but if it isn't, then what.
Don't guess. Find out what failed the test, look at the sheet that they gave you, it usually has a reason for the failure.
You don't give any clues, so I don't know the year of the vehicle, but if it's EFI you can connect an automotive code scanner to find out what the computer has to say on the subject. That's actually your best first step.
You can borrow, rent or buy a code scanner at most auto parts retailers.
How can you measure a time delay fuse with a multimeter to determine if it is good or bad?
Set the multimeter for the "buzz" mode. This mode checks for electrical continuity. This means that the multimeter checks to see if there is a path for electricity to pass through. Some multimeters indicate it with a buzz, others with a light. Put one lead at either end of the fuse, and if the indicator (buzz or light) goes off, the fuse is good. If it doesn't go off, the fuse is broken. If you don't know how to set your multimeter on that setting, or it does not have one, set the multimeter to measure resistance. If the fuse measures a really small resistance, it is good. If it measures at a really large resistance, it is broken.
Where is the fuel temp sensor on 2004 Hyundai Santa Fe?
try going to auto zone's website and looking under the "Vehicle Repair Guides" for your vehicle. I was able to find easy to read diagrams showing me where things were and how to replace them. Its kinda like an online Haynes manual!
well this is not the cause but the cure turn the ignition with key inserted half way then back then start the van, " no oil light" why i do not not drove from Ohio to Florida still driven it's an annoyonce if anything to me. someone said it might be the oil sending unit it's a sensor?
probably a vacume leak if possible let it run listen close under the hood for a whistling sound and maybe you can find it.
Use a code reader to check the engine diagnostic code using an OBDII code reader. If it's the gas cap you may need to replace the cap then reset the diagnostic codes by following the method described in the owners manual.
What causes a check engine light in a new scion tc?
iT COULD HAVE BEEN CAUSED BY "TOPPING OFF" THE GAS TANK. tHE EXTRA FUEL SPILLS OVER IN TO THE CHARCOAL CANISTER WHICH IS A PART OF THE EMMISIONS SYSTEM AND TRIPS THE CHECK ENGINE LIGHT TO COME ON.
What engine does the Humvee H1 come with?
Depending on model year, available engines included:
General Motors 5.7 liter Vortec 5700 gas engine
Detroit Diesel 6.2 liter naturally aspirated V8 diesel engine
Detroit Diesel 6.5 liter turbocharged diesel engine
Duramax 6.5 liter LB7 turbocharged diesel engine
Duramax 6.6 liter LLY turbocharged diesel engine
What does OBDII code P0446 Evaporative emissions control vent circuit mean?
The previous answer was good for high dust environments (and if you have a Ford Van all environments are to be treated as high dust) but for those of us in high corrosion environments, consider the following:
If you have an Explorer (Or Ranger/Mazda B-series) check for a broken wire near the left side framerail near the rear axle.
If you have a Hyundai (including Kia), Nissan (including Infinity) or Toyota (including Lexus or Scion) you should disconnect the electrical connector and then apply and remove 12V power to the vent solenoid/valve. The difference between 12V applied and not applied should be the difference between not being able to blow through it and being able to. After testing at least 5 times, if it fails even once, replace the solenoid/valve.
In the case of Nissan or Toyota, if replacing solenoid/valve it is usually best to replace the canister as well as you might inadvertently break the canister while replacing the solenoid/valve. With many Nissan vehicles, it is almost impossible to not break the canister without using techniques involving unreasonably high fire hazard.
Hey Brian==It is probably the gas cap not on tight. Have the codes removed and see if it comes back on after you tighten the cap.GoodluckJoe
Well, my experience with a 2000 GMC 3/4 ton truck says otherwise.
A loose gas cap will not give you P0446 because that is the code for a failed vent test.
Here's how it works: To check the vent system the engine vacuum valve is opened at the same time as the charcoal filter vent valve is closed. This creates a vacuum in the gas tank and when the vacuum reaches a certain level, the vacuum valve closes and the vent valve opens and a timer is started. If there is a restriction in the vent valve or it doesn't operate electrically, the tank fails to re-pressurize within the correct time and you get a P0446.
Here's what I did: I removed the vent valve and found it choked with a fine dust. I cleaned the valve, but noticed that there was lots of dust in the tube running down to the charcoal cannister and realized the gravel filter in the vent valve is useless at stopping dust. I took out the cannister and discovered an amazingamount of dust clogging it up. I cleaned the cannister by holding it vent side down and sharply tapping it many, many times it while blowing air (at low pressure) through it toward the vent side until it passed air freely both ways. Did I mention that there was an amazing amount of dust that came out of the cannister? I would think that gasoline residues from overfilling might clog up the cannister too, but that didn't happen in my case.
Below are what I consider the possible causes of P0446 in the order of least likelihood (IMO) for a vehicle used in a high dust environment:
Electrical vent driver circuit in computer burned out (especially if the vent valve is shorted), electrical vacuum valve driver circuit burnt out, vent valve coil open or shorted, vacuum valve coil open or shorted, bad vacuum sensor in the gas tank, vent valve filter clogged with dust, charcoal cannister clogged with dust or residues.
Removing and replacing the vent valve and especially the charcoal cannister in a GMC truck is a major, major pain in the a-- because the entire vehicle was carefully engineered by GMC so as to make replacement as difficult as possible. It does no good cleaning and replacing a clogged vent valve as the cannister will be clogged too. A new cannister is about $175, but a cleaned one is free.
BTW, my vent test works perfectly now. Added by Protoart: If you have the P0446 code and the vent valve is bad, don't continue to drive, or you will clog (saturate) the canister with gas for sure. My wife's 05 Scion, check engine light w/ P0441,0442, and 0446.......cleared with my scanner, never came back after I tightened the gas cap
How do you reset service lamp on 1999 Holden Commodore?
Re-setting Service Reminder Light VT and VX 1.Ignition switch OFF. 2. Hold down the trip computer "UP" and "DOWN", arrow buttons that control the vehicle information screen. 3. Turn the ignition ON while holding the 2 switches down. 4. After about 3 seconds release both buttons. 5.Press and release the MODE switch, the "Service reminder s" hould appear on the instrument cluster. 6. Press and hold both the trip computer "UP" and "DOWN", arrow buttons until a BEEP is heard (about 3 seconds) 7. Release both buttons and turn the ignition OFF.
How do you reset the check engine light on a 1994 ford mustang?
SOMETIMES YOU CAN UNHOOK THE BATTERY TERMINAL FROM THE BATTERY FOR 15 MIN .AND THAT WORKS ..BUT MOST OF THE TIME YOU HAVE TO A GARAGE AND HAVE THE MECHANIC HOOK UP HIS COMPUTER TO THE CAR COMPUTER TO CLEAR OUT THE CODES.. BUT IF THE PROBLEM THAT SET THE CODE STILL EXIST THE LIGHT WILL COME BACK ON. MOST OF THE TIME WHEN IT KICKS A CODE THERE IS A PROBLEM THAT NEEDS FIXED
What are emergency notification systems and attack warning signals designed to do?
Direct personnel and units to take pre planned defenssive action.
The gas cap may not have been put back on correctly after you filled the tank. This can create a vapor lock which triggers that light to come on.
Give the gas cap a few right turns to tighten it & make sure you hear several "clicks". Then drive as usual for several miles and the check engine light may go out. If it doesn't, give your auto service center a call or make an appt. as soon as possible.
Hope this helps!
The vapor lock resulting from the improper cap replacement does not cause the light to flash. It sounds like a more serious problem. Normally these are resulting from clogged fuel filters or vacuum leaks in the line.
Will anything in the ac cause the check engine light to come on?
Nothing except - maybe - a broken belt.
How do you reset the computer when the 'check engine' light comes on in a '94 Isuzu Rodeo?
First, if it is something like a loose gas cap, just tighten it and it will reset itself in the next 100 miles or so. If it is something else, like a leaky gas cap it will never reset. But to reset the OnBoardDiagnostic (OBD)Computer... Go to eBay and search "obdII" and buy one, they run about $50.00 including shipping. There are two types, ISO for Chrysler and some Japanese, and the other one for all the others like Ford and GM. There are several that are both, that is the kind you want. Be sure to email the eBay seller and ask if it is used with your year and model. (1996 was a changeover year for OBDII technology, so this advice may not apply to everybody--but the dealer service guy can tell you over the phone--ask him if it is OBDII compliant.) When you get it, you just plug it in and let it cycle 4 or 5 times and it resets everything. You then have to drive your car for 50 to 100 miles for the onboard computer to test everything, and in the meantime your car will fail smog checks because it has no history in the computer and the smog test procedure demands a history even if there is no pollution. Cut and Paste http://search.ebay.com/OBDII for a list of them for sale on eBay. Most units come with a list of generic fault codes so you can tell what the problem is, this could be very helpful.
There's a small sensor that sits in mid air on 2 hoses that come off one of the lines to the EGR valve. It has a 2 pole electrical connector going to it and sits about 6" above the driver valve cover and 8" behind the power steering fluid reservoir. It's Motorcraft part # should be 4U7E-9J460-AA. This is a common problem on the 4.6's especially. What's the year and engine size of your truck?
AnswerGo to another mechanic. If the light is on, then there is something wrong with the emissions system. Sounds like the EGR valve need cleaning or replacing. AnswerMiata engines typically run very rich and it is not uncommon for carbon deposits to build up enough to clog smaller ports on the emissions system. The common culprits are :1. Crudding on the EGR Valve itself, which will cause the mechanism to freeze. You can review cleaning this at the following site:
http://sites.google.com/site/redcapsmiata/tutorials/egr-valve
2. The port after the EGR valve, which runs into the front of the intake manifold:
http://miata.net/garage/manifold/index.html
Both cleanings can be done by people with a basic, mechanical aptitude.
Where can you find DRB-II Scan?
Are you wanting to buy a scanner, or are you looking for the port?
If you want the scanner, eBay is probably your best bet, or maybe a local dealership would be willing to sell you one of their old units.
If you're looking for the port the location can vary from vehicle to vehicle but you're most likely to find it just behind the battery.
How do you get check engine light off on 1997 Geo Tracker?
Hi, You can or have someone, usually a garage, reset the light by using a device that hooks up to the data port which is at the bottom of the dash where your right knee is. The most important thing is to have someone hook up a code reader and tell you what code is coming up that is turning the light on. When you find the code then you can be led to whatever sensor is the culpprit. As I have found that when it has been a long time on, there are or can be, a whole host of things wrong from the Vehicle Speed Sensor (VSS) in the speedometer, the speedo cable, the EGR valve, the EGR bypass valve, the oxygen sensors...that's just a few. I thought I'd remove the bulb from the rear of the instrument panel but then what does that do? The problem still exists the indicator is only gone. The best bet is to have someone read the codes and tell you what is wrong, only then when the offending sensor or part is fixed, can the light be turned off and stay off. Good luck even though I realize it's not the answer you wanted to see. Steve H. This usually means something monitored by the computer needs fixingor replacing. Take it in to AutoZone and they will plug it in and tell you what is wrong. Mike
How do i get the check engine light codes on a 2004 dodge neon?
Cycle the key to the ON position, then to OFF, then to ON, then to OFF then to ON and leave it there. Where the miles are normally displayed a letter P and a set of numbers will come up. EX: P0303. Once it says DONE it is done displaying the codes. When you have the code(s) use google to look them up. "2004 Dodge Neon trouble codes".
What does check engine symbol looks like?
The check engine light has a couple of variations, but is overall similar in all vehicles. It appears as either a small engine symbol with the words 'Check Engine," or without the words (or without the symbol and only the words).
You might also see:
- Service Engine Soon.
- Check.
- An engine with a hazard symbol on it.
(See related Links for images of the Check Engine light)
If your asking what the symbol is meant to look like, its an engine.
How do you reset the service engine soon light on 2003 Mitsubishi?
Go to your local Auto zone they will read it for free. If there are no faults they will reset it if it has faults they will tell you what to fix.
What would make a check engine light go on in a 1998 Honda Accord EX 98?
From my experience, its usually the bank 1 oxygen sensor. Lemme guess it sometimes goes off. But, always come back. Some strange reason the most expensive oxygen sensor goes out on the 98 Accords. Just to be sure find someone with a OBDIII reader, just to make sure. If it's a 4 cyl it could be the gas cap being loose.The convertor being worn (if it is and under 80k bring it to a dealer it will be for free)It could the fuel pressure regulor.But the most common is the canistor vent shut valve. If it is a V6 gas cap loose, canistor vent shut valve inop. or the convetor or the EGR tubing is clogged. If it's the EGR bring ti to the shop the intake maniflod must be removed and drilled and egr valve be replaced. Plus 8 yrs 80K miles all emission stuff is free. I have never seen a 98 Accord with a bad O2 sensor. Our Check engine lightm came on. We took it to "Auto Zone" parts shop. Their 'machine' said it was an O2 sensor. But when we took it to a car dealer, their 'machine' said it was the Cadalitic Converter. 2 weeks ago the light went off and hasn't come back on.
If it flashes it means damage is being done to the converter, don't drive it in this condition. If it does not flash, take it into an independent garage to have it looked at within a few weeks. It is emmission related. The " check engine light" is by far one of the most misunderstood technological advances by the public. I am sure I will revise this as time goes on, as it is an in-depth understanding for the public. It is a warning light that is illuminated when there is a problem with the EMISSION SYSTEM only. Emission system being the pollution control system. Don't get a hard on against it as it is a good thing once you understand it. One point that was brought up a a recent meeting of technicians was that the amount of hydrocarbons is greater when the gas cap is left off than when the engine is running. Hydrocarbons are part of pollution emitted as gasoline evaporates. Going a step farther, one facet of the emission system is the "Evaporative" portion. This is when the fumes from the gasoline are leaking from the system into the outside air. This is one part of the emission system that can trigger a check engine light. I would say that about 7% of the vehicles that have a check engine light are the result of a loose or inadequate gas cap. But understand that many scenarios are possible with the "check engine light" The vehicle's powertrain computer (note that some vehicles have 17 different computers) will run a series of self-tests. They will only run under certain criteria. And they can be vastly different from manufacturer to manufacturer. Some self-tests are not run until preceding ones have run successfully. So if there is a problem in one particular area that is preventing another self test from running, you can have a situation where one problem is fixed, but another still exists. If you fix a problem and drive the car through a drive cycle that sets the monitor (or self test) the light will go off as it passes that criteria that triggered it in the first place. After 1996, the auto industry went to a idea called OBD II (on board diagnostics). This was to get all the manufacturers onto a similar plane for troubleshooting and powertrain control. While they still differ vastly, many corrections and adaptations were made for technicians to better fix the check engine light problems. Prior to this there were so many different and poor troubleshooting data from a check engine light problem that resolving the problem was much more difficult. Many early warning light of this nature were set to illuminate based on mileage. An Oxygen sensor was one of the things that were meant to be replaced when that mileage was hit. This is much like many current "Change oil lights
