Check Engine Light

1996 and later Explorers use an electronic speedometer which is operated by a vehicle speed sensor (VSS) The powertrain control module also uses the vehicle speed sensor input signal for several different engine and transmission control functions.

I have a 95 Tracker as well and recently it turned 100,000 miles. At 100,001 the "check engine light" came on. A local mechanic did a diagnostic and it also didn't give any codes to help reset the light or alert me of a problem. I asked him about the reset "switch" under the dash and he said he never heard of that. I investigated on my own when I got home, because the light being on was driving me crazy, and there actually is a small switch that reset the light. I removed the small plastic panel under the steering column and found it between the drivers side speaker and the steering column. It is really small. It is a black plastic switch with a metal face plate. You really have to look for it because it's settled in with the wire harness' under the dash. I flipped the switch and the light went out. Again be patient when looking for the switch. It's there you just have to look close to the dash and next to the steering column. I tried removing the battery cables because I read that that would reset the light but had no luck doing it no matter how long I left them off.

If your check engine light has come on, that means the cars computer a detected something wrong. If everything seems to be in order, take it to an auto parts store "Auto Zone", and the will hook up an OBDII scanner "On Board Diagnostics system" and that will give them a code and they can look up that code and tell you what has set the check engine light off and then they can clear the code.

You have to have a "code reader" to first read the trouble code and then to reset the trouble code in the vehicle's on board computer system. The "code reader" is available from most auto parts stores and will work on most newer vehicles.

Basically if the check engine light goes off it means the fault is not permanent and not consistent. The fault came and after so many cycles the PCM said there's a problem and it lit up the check engine lite. After so many cycles of the fault correcting itself the PCM then stopped the light from being on. Nevertheless the PCM always usually records this fault in its history of faults for retrieval later on via a scanner

== I have heard that sometimes if the gas cap is not on tightly, or the door to the gas cap is not completely closed, that the check engine light may come on. Perhaps it settles after a few days after going over a few bumps.

If you are checking a Chrysler/Dodge 55 is "end of message". It just means that there are no more codes to show. If that is the only code you got , then there are no codes.

Trouble code P0420 means:Catalyst system efficiency below threshold

If the check engine light stays on , a malfunction with the emission control system has been detected , have your Ranger scanned for any trouble codes to diagnose and then repair the malfunction

Pushing the "OFF" button, and the "WARM" buttons TOGETHER, will read the codes. Pushing the "OFF" and "HI" buttons TOGETHER to clear codes. Assumingthe cause of the light initially to come on, was corrected, the light should go off. Good luck

Disconnect the negative battery cable for a couple of minutes, then reconnect. This will clear the error codes from the computer. If everything is okay, the light will stay off.

It's probably in the "clock spring" in the steering column. I just had mine replaced. The airbag light was flshing 3 then 2....It's not cheap and you really need a professional to do it.

get the engine serviced.

Closed fuel control insufficient coolant temp. Check out this site.

evaporator emission system pressure senser

My advice it to have this done at a muffler shop.

this is normally caused by water entering the electronics of the engine. The most poular is the distributer cap. open cap and allow to completely dry and reasemble and see if that solves the problem.

That is the check engine light. It will come on and stay on when the computer has detected a problem with the emissions system on the vehicle.

If the VSC flashing light comes on at the same time on your Toyota Corolla, then there might be a sensor issue, and if you have a warranty, have it back to the manufacturer.

I have a daewoo matiz that has low power when the engine light comes on I have changed the spark plugs/leads/distributer cap/distributer/and coil checked the timing changed the fuel filter air filter and it still looses power when the engine light comes on.

You have spent a lot of money and you still have the problem. Do you not think it might be time to take it to an expert and have it repaired correctly. You would've been money ahead right at this moment.

Question..... I was wondering if anyone could help with a problem my wife has been having with her 2003 Jeep Liberty Limited. The vehicle has 88K miles and runs well. About 2 months ago, the check engine light came on and wouldn't go off. My wife took it in for an early oil change and diagnostic. The oil change didn't solve the problem and the diagnostic showed nothing wrong. Then a few days later, the light went off. A few days later the light came back on again. She then brought the vehicle to a mechanic and, after diagnosing the vehicle for over 2 hours, decided that the gas cap needed to be replaced. The light went off. 2 days later, the light came back on again. Brought the vehicle back to the same mechanic who did a full oil change, tune-up and replaced the gas sensor. The light went off. That was yesterday. Today, the light came back on again. I refuse to bring it to another mechanic and have them "guess" at the problem, charge us an arm and a leg and wind up having the liht come back on a few days later. Any suggestions?

You can contact me at adamscrnr@comcast.net

Thanks to anyone who can assist..

Jim

It has to ba done with a scanner. Take it to a autozone or other parts store and they will read the codes

Don't waste your time at autozone. Pull 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. Therefore, another problem may exist. It is emission related. OR hook up a scanner that is capable of clearing codes, and hope that none are still active. Disconnecting the battery can create other headaches and will not likely solve your dilemma. Best bet is to contact the local snap-on dealer and have him refer you to a known good shop that specializes in this technology-he will know.

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? that are set based on a pre-set mileage. BCLEAR.

BCLEAR - your answer in reference to the engine light coming on due to an emisions problem may be on target. My wife went to put gas in our 2002 Jeep Liberty and noticed that the gas cap was missing. She was concerned that an old friend that she is fuding with put sugar in the gas tank and stole the gas cap in the process. Shortly after fueling up the check engine light came on. Obviously I did some research on what sugar in the gas does and learned that most of the stories are urban legends because sugar does not disolve in gas. The engine light came on only after she drove the car without a gas cap. I will get a new one today and see if that clears out the code. Don

Best thing to do is remove the negative cable on the battery and let set over 15 to 20 min. Then reconnect and see if it went out some times its just a matter of resetting the computer for routine maintenance. Had light come on after fuel injection cleaning. Pulled negative terminal and the light has never come back on.

_ Comment: I find that everytime I fill my almost emtpy gas tank with gasoline containing 10% ethenol my check engine like comes on. Only after filling my almost empty gas tank again with gas not containing ethenol my check engine light goes out. (after half a tank of gas is burned.) You can read the content of the gasoline that you are purchasing usually on the pump. Most time it is in small lettering. I hope this is helpful it works for me. Try this first you won't waste alot of trips to the dealer and most dealers don't know this. I just descovered the pattern myself.

At about 90,000 miles, my check engine light came on as well. My mechanic ran diagnosis on it....I had cracks in my emissions tubing. After replacing the tubing...cheap fix...the light went off.

With the engine off, press and hold the odometer reset pushbutton. Start the car. Keep finger on odometer reset pushbutton until "oil life" message starts flashing. Release the button.

Maybe. You need to get an ODBII diagnosis first to see what is causing the light to come on. ed724 It is worth doing since it is a maintenance type of need. There are tune up parts that could cause a check engine light. If not then read below: Pull 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. Therefore, another problem may exist. It is emission related. OR hook up a scanner that is capable of clearing codes, and hope that none are still active. 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

If these two lights come on together then the extra traction sensor is broken and needs to be replaced when the sensor is fixed the check engine light will go off and the ets light will work properly again.

Turn the ignition to the "ON" position. Not the "RUN" position. The engine should be off. With the ignition in the "ON" position fully press the gas pedal down 3 times within 5 seconds. The light should flash twice. If it doesn't you need to try resetting the system again. read your owner"s manual