Check Engine Light

I hear this line at least once a week. The instrument panel on most cars is absolutely cluttered with warning indicator lights and buzzers. These lights are color-coordinated so that different colors indicate the severity of the potential problem. As you start the car, all of the lights should come on, and as the computer verifies each component is working properly, the light is turned off. You should only be concerned with lights that remain on for several minutes after the car has been started. Check engine or service engine soon lights can be tricky to repair, so a little help on your part could really save the mechanic some diagnostic time, and save you some money! Treat check engine lights-service engine soon lights, and all dash lights like traffic signals. A Red Warning light indicates an immediate danger. Pull over, turn off the car immediately and assess the problem. Symptoms that usually cause red warning lights are engine over-heating, low oil pressure, transmission over-heating, low battery voltage, and brake failure. Red lights can also indicate a safety issue, so proceed with caution as you maneuver to stop the vehicle. Unfortunately, when the red light is illuminated the problem is at its peek. It can be a matter of seconds before permanent engine damage occurs. Some common things to look for when a red light comes on are: low anti-freeze, engine oil, and transmission fluid levels low brake fluid missing belts faulty alternator that is not charging the battery or a bad battery A Yellow Warning light, (Usually a Service engine soon light) indicates "Proceed with caution." The onboard computer system has indicated a potential problem and is alerting the driver. This computer system resets and re-tests all sensors and indicators each time the car is started. The computer system is capable of correcting some minor abnormalities, but if the light continues to come on after multiple car starts, it is probably sensing something that would imply a visit to the diagnostic mechanic is in order. Some common things that may cause a yellow light (Service engine soon light) to come on, but will probably require an experienced technician to diagnose are: anti-lock brake systems safety restraint systems, such as air bags emissions components computer-related problems, such as faulty sensors If you are driving your car and a yellow light comes on, ask yourself these questions: 1. Did you notice problems when starting the car? (slower to start than normal..etc.) 2. Have you noticed a decrease in fuel mileage recently? 3. What is the over-all running condition of the car? Is the engine misfiring or not performing like normal? Are there any new noises from under the hood? Turn off the radio and listen closely as you drive the car. 4. Do you notice any odors, such as a rotten egg smell, or see visible smoke from the tail-pipe or from under the hood? Make sure to note the exact location and wording of the light that has been coming on, because Murphy's Law dictates that the light will suddenly not come on when you take it in to the repair shop. In some cars, "engine" is the more serious red light, whereas others use "check engine light," which is a yellow caution light. If the mechanic thinks you are seeing a yellow "check engine light," and your car is indicating a red "engine" danger light, this could be a costly mistake for both of you. Why? You could be having a serious over heating problem and the mechanic is assuming you are having a less serious caution light illuminating. The mechanic then might give you the "green light" (no pun intended) to proceed with your out of town road trip with the kids. Yikes! Start the car, and point to the light to ensure good communication of the problem. Intermittent dash warning lights can be a pain and hard to diagnose! Diagnosing the problem in some cases will require the light to be on while the mechanic performs the diagnostic test. If the light is not on when you bring the car to the shop, you might be wasting your time and the mechanic's. SIDE NOTE: Keep a "running condition and dash light" log in your car to help the mechanic pin point the root of the problem. I have a customer who keeps such an accurate log of her cars' complaints that sometimes I can diagnose the problem correctly with the help of her log and by taking her along on my initial test drive. I can do my diagnosis usually without opening the hood to her car. This saves me time and she saves money on a diagnostic charge. This customer can also hold me to my warranty time period, because she had this particular complaint written in her log book.

I would try adding some fuel injection cleaner with your next tank of gas. This has helped me with minor engine misses and/or hard starting conditions. HAVE THE COMBUSTION CHAMBER AND THE FUEL INJECTORS CLEANED. It sounds like this did not start with the last plug change. I have found in the past that the "Coils on Plugs" seem to start loosing the spark about 50,000 to 65,000 miles on my Fords. It happens cause they run so hot. At least here in the Texas heat....Anyway, it sounds like you have one weak plug or one weak coil. There is a way to check these coils to find the bad ones and I'm sure someone one the web will tell you. But, I'm lazy, if I'm going in there for one coil, I will do them all and the plugs at the same time. My luck would be to have another one go bad after a week or so, so, change them all. It is always worth the investment.

HI; I just stumbled across your question. pao is not pao, the D looks like an O is all. It means that one of your brake pad sensors has either an open or you need to replace your brake pads. Also, the pads leave about 1/16" of the rotor exposed on the outer edge after time causing a lip to form as the rotor wears. This lip will eventually cut into the sensor and cause your light to come on, sometimes prematurely. Turning these rotors is not reccomended as we have had problems with original equipment Jaguar rotors having hard spots from inconsistancies in the metal We always replace the rotors when the lip is too severe or if they are warped. Our pricing on brake parts is excellent and we package rotor pad and sensor kits. See http://www.captainjaguarscathouse.com. Your other question relates to fuse failure. You should also have a warning light on that looks like a lightening bolt. If you do not, turn on your ignition and look at all the lights as they light up in the insrument cluster before extinguishing. This is the bulb check cycle of the start up process. If you have one out, check the bulb in the instruments. This warning light and Circuit 1 failure showing indicate you have a fuse blown. Get your test light and run tests on both fuse terminals in both A post kick panel fuse boxes located to your left on the drivers side and on the right on the passenger side. This is assuming you have a left hand drive car.

It could be just a loose gas cap!

You can try disconnection the battery for 10-15 min but if there is a problem that turned the light on to begin with it won't go away without the problem being fixed.

On all ford V blocks, Cylinder one is the first on the left, as you face the engine from the front. On most Ford engines the #1 cylinder is the first cylinder at the front of the engine on the passenger side (right side). Counting back from there puts #4 at the back of the right side, and number 5 in the front of the left side. Number 6 would be the second one back on the left side.

Trouble code P0042 means:HO2S heater control circuit (Bank 1 Sensor 3)

You will need a scanner to turn the light off. But if you have not repaired the problem it will come right back on. There is some auto parts stores that will turn light off for free.

Intermittant problem. The " check engine light" is by far one of the most misunderstood technological advances by the public. This is an needed in-depth understanding for the public. It is a warning light that is illuminated when there is a problem affecting 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

Many of the code scanners that are available will reset codes and turn off the indicator light IF THAT IS POSSIBLE WITH YOUR VEHICLE. Since all vehicle manufacturers have a different idea of what's the right way to build a car, they all have different ways to build a computer as well.

On this model Toyota , there is a input sensor that reads the speed and also the input on the selector shaft for the 4wd, it reads the position of the arm and gear. if it fails to engage or align , this will cause the 4x4 light to flash. there is a failure.especially if you ride in AUTO where it switches on and off, it has monitored a failure, either it has not engaged when told to or it has not dis-engaged when the control module has told it to until needed. If you are in auto, or system off, with vehicle cold, warm to normal operating and then text book turn on /set manually for the 4WD to engage. listen for any gear clatter or harsh syncronizing sounds. if the light has stopped flashing and stays permanantlly on the 4wd has sucesfully engaged. make a small pass in forward gear and revers and then manually turn off the 4WD system, if the light stays off everything is well. people may say just disconnect the battery for 10-15 sec and that will reset the light, yes and no. many toyotas have "retained power/retained memory" and keep alive power so yu may have to keep it disconnected for about 5-10 min. if yu like and then if the lights off repeat steps of manually engaging and dissengaging the 4WD.

Kongkit Raggan-Supatanampon

It is caused when the onboard computer detects a fault. Use a computer diagnostic scanner to find out which specific fault has been detected. Often the description of the codes is a bit obscure and it can take a little head-scratching and investigating to figure out what the cryptic message may mean. just go to autozone or any parts place and most of the time they have a scan tool and will let you use it to find out whats wrong. quick and ez and you are allredy at the store. the check engine light can come on for many different reasons. some reasons are minor (filled with gas while engine running) others can be bad (engine trouble). the best thing to do, if your car runs okay, disconnect the red battery terminal and reconnect. the check engine light should be off

It could be your O2 sensors going bad. I had the same problem. you may also want to check the ignition coil

I assume you are speaking of your CHECK ENGINE Light. Since you are driving a 1989 GM - it could be a bunch of things. Try this. Disconnect BOTH battery Cables. Touch them together for 10 seconds. Reconnent the cables to the battery. This can sometimes reset the computer. But, you'll have to reprogram the time and favorites on your Radio, etc... If, after doing this, the light comes back on. You'll need to take it to a servicer who can determine which code is causing the light to come on. Then you can get it fixed. Hope this helps. I don't know if this applies to your problem as my year of make is newer (2004) but, IF your Gas cap is NOT 'Clicked' tightly, it CAN cause the "Check Engine" red light to come on...and it will stay on until the cap is properly setin place. I hope it is this easy. Good Luck. LOL on your first answer.....first off, a grand marquis is not a gm. and on this model of vehicle there are 2 engine lights. one says "engine" the other says "check engine".......in your manual for the ccar, it tells you that this light will come in if the oil pressure is too low, or coolant is low and engine is getting too hot. this is a factual answer lol. this guy above cracks me up saying a mercury is a gm product...its a ford dude. haha

It is round, black, cylindrical and mounted on the engine compartment firewall almost directly below the right side windshield wiper.

yes because there isn't enough oil isn't getting to the motor yes.a severely clogged filter can cause a lean condition triggering sensor codes activating the check engine light.

tcs is part of a separate control unit(tcm) attached to the main pcm. when there is a problem with abv, the pcm stops communicating with tcm(transmission control module), and the car is put in "limp home" mode(tcs off/tcs lites illuminate, car will not rev above 2500). quite common in the 2.3, generally, a vacuum line problem. you probably also have codes p1525/26 and/or 1540. first fix the vacuum lines, change out the tees and the lines(about 21 feet), next would be the vacuum/vent solenoids in the back of the engine. one or both of those generally fixes this problem

The Check Engine light is on because there is a problem with the emissions system. Once you have the problem repaired the light will go off.

Take a look here askville.amazon.com/service-engine-light-wrong-saturn-Vue-2003/AnswerViewer.do?requestId=3645084

There's no great ''trade secret'' as to how to reset the service indicator lamp on most Vauxhall's, simply refer to pages in the Owner's Handbook! For reference of those interested in such matters, but who might not have access to an owner's manual, this is the procedure to follow: Vauxhall service reset * Turn Ignition Off * Hold Trip Reset In * Turn Ignition On Still Holding * Trip Reset wait for three dashes * Turn off Ignition * Turn on Ignition to confirm To the best of my knowledge, the above service light reset procedure applicable to most Vauxhalls HOPE THIS SAVES YOU PAYING FOR INFORMATION!!!!!!!!!!!!!!!!!!!! ;-)

you can only reset it with an OBDII diagnostic code reader.

I recently replaced the battery in my '97 Sephia, and took it in to get inspected. They said that because my battery had been replaced that morning, the computer had reset and I would have to drive it for about 75 miles to reset the codes (if present). So I drove it a while and took it back, and it was ok. I tried that the next time the check engine light came on, and the light went away (for about 75 miles, then the computer reset and it came back on). If you have recently acquired this car, you'll find out that the check engine light and the associated problems are common with '97 Sephia's. Good Luck!

If you reset the code for the check engine light and it comes back on after a while of driving that means that you just reset the code not fixed the problem. You will have to goto someone who has a tech to that they can hook upi to your computer and there will be a code that will come up and the mechanic should be able to tell you what is wrong.

The " check engine light" is by far one of the most misunderstood technological advances It is a warning light that is illuminated when there is a problem affecting the EMISSIONS of the vehicle.. Don't let it bother you as it is a good thing once you understand it. One point that was brought up 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 a small percentage 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 multiple computers aside from the powertain computer) will run a series of self-tests. They will only run under certain criteria. And they are different from manufacturer to manufacturer. Some self-tests or �monitors� 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. There are many different sources for the light to come on. Anything that caused combustion to fail, commonly called a misfire will set the light. Various sensors such as oxygen sensors that evaluate the exhaust before and after the gases are burned in the converter. Transmission codes may set the check engine light to appear. If the car is running okay, get it fixed in a reasonable amount of time such as within the month. It will probably save you fuel if you do. However if the Check engine light is flashing, you should be driving it as damage is being done to the converter. Some emission components are covered beyond the standard warranty. The converter for example is covered up to 80,000 miles by the manufacturer. 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, 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� that are set based on a pre-set mileage. To start testing for the check engine light, you�ll need to find the codes from the computer, match the code to the troubleshooting procedure, follow the procedure to find the source. Repair the source, light will go out if that was the only problem. There are "monitors" or self tests the computer runs the car through a drive cycle, if a problem occurs, it may not run all of the self tests until that problem is taken care. There are self-tests for the oxygen sensor circuit, egr system, evaporative system to name a few. Therefore, another problem may exist. It is emission related.

OR hook up a scanner that is capable of clearing codes, and hope that it won�t come back on. But don�t bet on it. Lastly, disconnecting the battery in some cars will clear the memory of the computer and may temporarily turn the light off. Beware that this may also cause other problems such as the car not rembering it�s idle and will have to relearn it, the radio may be rendered inoperative or in the case of the new Toyotas, the air bag can blow.