Check Engine Light

there are everal symbols, battery, handbrake,airbag, if its diesel you'll have a coil heating light, oil low indicator, headlights,sidelights,mainbeam

Borrow, rent or buy an up-scale OBD-II code scanner for a GM vehicle. You should then be able to plug in the scanner and clear the codes. If the scanner does not turn off the light, you might want to find out if something else is wrong. In any case, it's a good idea to have your own code scanner, and the upgraded version is better since it lets you clear codes. if the problem is fixed then your pcm will shut it off automatically after 50 or so starts with the code not being thrown again. or you can take it to autozone and they will shut it off for you free of charge.

Have vehicle scanned to determine the problem

Check the inside of the distributor cap. Moisture there will prevent an engine from running. Note that YOUR problem may be something else, but you can start by checking there.

Thats the $50,000 question. It is not easy diagnosing todays engine faults because sometime all you have is a code and it will not point directly to a certain device. Did you drive your vehicle at least 50 miles and a couple of days to see if the check engine light goes out now that you tightened the fuel cap? The computer will not automaticaly reset the check engine light if you tighten the cap. It has to go through a certain amount of miles and cycles so it knows the problem is fixed so don't be too fast to rush to another fix here. If it stays on I start with an O2 sensor since it has a lot to do with emissions. That is where I go and from there diagnose that to see if it is working properly. Best I can do for you now...............

Have vehicle scanned to determine problem Have vehicle scanned to determine problem

Depending on the vehicle, it is usually an ignition lead or spark plug.

There can be far more problems however, Injectors, burnt valves, leaky intake manifold, blown head gasket, individual coils, and the list goes on, if it misfires under load, ie. going up hill in a low gear then it is more likely an electrical misfire, if it is all the time and very constant then it may be one of the other options listed above.

It may be easier to figure out by knowing what type of vehicle it is and what year.

the po420 could also be a misfire or vacuum leak

because you have either fouled a spark plug or lost a plug wire or maybe collasped a lifter, and also maybe burned a valve . there are more than a few possibilities.

On some if you turn key on, off, on, off, on. The check engine light may start to flash the code. blink, blink, bink, pause blink would be 31.

Check to see if any of the codes came back. Typically, if something is wrong that caused a code, it won't go away until the problem is resolved.

Connect a code scanner to see what it can detect.

Could be spark Plugs , Spark Plug Wires, Or could even be the Coil Packs. Not uncommon to replace coil packs every couple of years. There is 3 coil packs . That is one pack for 2 firing cylinders. they are easy to change. 2 small screws hold in each coil pack. you can buy just one coil pack and then just trade it around in your carand see which pack is bad. YOu can buy them at parts places such as Advance auto or Autozone for about 20-25 dollars. those are the first 3 things that i would try.

Lastly it could be in the electronic module. that is the meat peice under the 3 coil packs , usually when this goes out the car will not start up at all.

The check engine light can come on for literally thousands of reasons. If the truck is still running well, odds are it's nothing too serious. See related links for a free article I wrote that explains in more detail.

The ignition switch

ECU

Fuses

or The main relay

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This is a can of worms! Thankfully I just opened it myself after swapping the engine in my 93!

Firstly, check the main grounding cables in the engine bay. The most prone to failure is the one that goes to the thermostat housing, but check the others too.

Next check all your fuses and relays, information on this is available at almost every Honda forum - the Main Relay is a common failure.

http://autorepair.about.com/od/enginetroubleshootin1/a/hon_mnrelay_tst.htm

http://autorepair.about.com/od/enginetroubleshootin1/a/honda_hot_start.htm

If the engine is turning over but not sparking you may have a problem with your fuel delivery or distributor cap - in my case I simply swapped the cap and rotor arm with a known working one - it didn't solve my problem :|

I then took the fuel delivery hose from the rail, popped it into a clear food bag and had a friend crank the engine - no fuel... He cranked it 8 times and no fuel...

Suddenly though there is no more check engine light... back to the ground cable tests.... All were fine, but to make sure I removed them all, added a little solvent to each point, put some copper grease on the terminals and bolted them back in.

Turned the key and the fuel pump audibly worked... one more click and vroohoom.... my lovely Honda roared the roar of the angry.

to many things to count, if it still runs fine it is usually something like an egr sensor or o2 sensor, it could be any bad sensor or any other electrical problem, the only real way to find out is to check it with a code reader or scan tool, most parts stores will check it for free and then try and sell you the part, a shop will charge a fortune just to look at it

You could try disconnecting the battery for ten minutes that would clear the engine light. If it clears the light then comes back on later then the loose cap was not the reason. ==Answer == More than likely the loose cap was the culprit. After a few driving cycles the light should go out. If it does not go out, you could take it to a Parts Store such as Auto Zone and explain what happened and ask them to reset the light. Then if the light comes back on you will know it was not the loos cap.

alot, check all the basics as stated in manual... ...everyone should have a manual for their vehicle(parts store or dealer), and a local library should have professional shop manuals available in the REFERENCE section for free...make copies of the appropriate sections...read up and good luck :) == The manual isn't gonna tell you SH**== I don't know the answer either, but the check engine light will probably show a misfire code, but check anyways. I now the motors are common for head gasket troubles. IF there is a sign of rich burning, I would question lack of spark or compression.

Not to be coarse, but that may have not been the problem or another was created during the repair or yet even still another problem existed and created the one you just fixed. If the ses light came back on, there will be code (s) stored. Get back on the horse and track them down. Troubleshooting can be very trying.

If there's something wrong with the oxygen sensor, and it switches lean, then switches back rich to correct, it'll set off both codes.

the light is a warning to you that something is wrong and your engine is not operating correctly and needs to be serviced soon. Most times there is a part of the emissions systems that set it off, like a bad sensor somewhere. You will need to get the CODES read. The codes are then converted to a diagnostic problem and then the parts of that system need to be analyzed to see which one is not operating. I will ask this....did you just recently get gas? You must turn the gas 3 clicks when you put it back on to make sure the correct pressure is in the gas tank otherwise you will get a check engine light. So go check your gas cap and if it is tight.........then you will need to take your car to a place liek Autozone and they will put a diagnostic scan tool on your car usually under the dash under the steering column and pull your codes. From there it is up to you where you decide to get it fixed, either by yourself or a garage. By the way after you tighten the gas cap you will need to drive some miles AND go thru a few stop and start cycles with the engine befoer the service engine light goes out if it was a gas cap issue. The light will not automatically turn off after you tighten the cap.

check the oil in engine to see if it has coolant in it

white smoke is caused by coolant or water burning with fuel
sounds like you have a blown head gasket
i would also find a better mechanic

Either you will pay a dealership or car mechanic to look up the code, have them fix your car, and have them clear the code or you can fix it yourself, and disconnect the ground on the battery for about a minute and hook it back up. Should clear the code.

This sounds like your wheel hubs need replaced. These are where the sensors for ABS and Traction control are located. I'm very surprised a dealer would not be able to find this. It is possible another sensor is bad, but this is the same problem I had with my 2001 Alero.

If you have service engine light on, trac. off light and the ABS light on the same time, you may be able to get it fixed my reprogramming the power control module (with updated software calibration). Mine was fixed for free at a dealer under a recall campaign when GM called me yesterday.

You may have knocked off a wire when you reconnected the starter wire, Check the wire going to the O2 sensor. if this isn't it take it to a shop and have them scan the ecm. It could be a flewk.good luck....Michael