check engine light on?

This could be many things, it could be spark arcing from your plug wires and causing shorts, it could be a faulty plug to one of your sensors, it could also be that you got some dirt or mild rust build up on one of your screens in your injectors(I doubt this one though), it could be a bad fuel pump and the computer is scrambling to make up for the lost output of the fuel pump. More than likely it is in your ignition system somewhere, take it to a dealer and you will find it to be cheaper in the long run for them to diagnose it instead of keeping on replacing random parts. Trust me, you will be glad you did.

Lets use this guide to help find out

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

i have put it on a scanner and no one can tell me why the light might be gone for a week or an hour. i am a quad mech. so i do under stand what you are saying will the screens in the injectors be clean able ?

I have never had to clean the screan on an injector but I do know that this is a random problem with some of the older trucks. Electrical problems are hard to diagnose unless the person looking at it is an expert, it really does sound like an electrical problem either with the ignition system or something that controls the ignition system. Some vehicles have an ignition model on the engines equiped with a distributor and this can be the cause too. If you have a wire that is backing out of a plug or a faulty wire that is almost broken, this will cause it too. A good way to find the electrical problem is too have a person sitting behind the wheel of the truck while you do a shake down on the wiring system and have them tell you immediately when the light comes on, this will help narrow down the location. If it is something like an ignition module, or relay, then what is happening is that after a while it gets too hot and it sets off the idiot lights on your dash and if this is the problem, you will notice that it is gradually getting worse.

thanks will give that a try

I have a 2001 Dodge Dakota Quad Cab Pickup with a 3.9L 6Cyl., Automatic transmission, 102,500 miles. I bought the truck about a year ago from a friend in our neighborhood (the original owner).

The truck runs great, but on humid or high moisture days my truck starts throwing PCodes. It will start by throwing a P0152 and then later throws a P1740. The next day the check engine light will turn off and I check the PCodes and they are gone ... the truck runs great again! Sometimes if I disconnect the negative post and turn the ignition to on and then off to clear the computer and reconnect the neg. post the truck runs great again. What is going on? The transmission seems to be strong and will climb a steep hill with no problems (also accelerates up the hill) ... there is no slippage in the tranny.

This past week on a extremely humid day, the truck disengaged the Overdrive and switched the transmission into 3rd. I limped home and the next day I started the truck and it was fine again.

On days that the temperature is below 45 degrees F, the truck runs like a new truck. I spoke with some of my Dodge Truck friends and they seem to think that I need to pickup some electrical paste and coat the connecters on the computer / wiring harness. I don't understand what is going on ... is my computer getting ready to die? Can you shed some light on this mystery?

Many thanks!

How old is the air filter?

The air filter is about 4-6 months old ... and is clean.

Last night while driving, my torque converter started slipping ... lots of noise. I made it home and parked the truck on the street. Ten minutes later I fired up the engine and the transmission was working again. I was able to drive the truck up our steep driveway and park it. Oh, no sounds from the torque converter either. It almost sounds like the electronics in the tranny are going out. Could be the Torque Converter Control module and/or the Overdrive Sensor have started to go bad.

By replacing the powertrain control module will that fix the problem? if so, were can I buy a PCM for my truck, localy?

You need to call around to any dealer with its 8 digit part number, whether it fixes it or not, I sure hope so, it has an internal failure, they can ship one out to you, ok?

light came on so i had it hooked up to scanner ,it said 02 censor bank2/1 was bad so i replaced it and reset light light came back on after 200 miles code said slow 02 censor 2/1 but while we had it hooked up all 02 censors were working prop except 2/2 it was working very slow so we changed it and reset light light came back on after 300 miles same reading slow 02 censor 2.1 but scanner shows they are working prop I was told comp mite have to be reprogramed or updated or i mite have to get 02 censor from dealer. sensors were from carquest can you help

Your advice has been excellent. I can add only one thing. Call your local dealer and speak with them about the situation. If replacing all these sensors and reprogramming is cheap enough, that is the way to go. If you just replace one with a fealer part, the trouble may still exist. Have the dealer give you a price on a complete diagnostic check of the computer and all fuel system components so after it is repaired, it will be their warranty to keep the complete o2 system working right for a good long time as it has until the code. A bad PCM should have shown up before this mileage, and if you put the dealer part in yourself, it may come back at you. Their sensors are designed for their computer(PCM). ok Joe

Wondering why my engine light comes on and stays on for a couple of months, then one day it will go back off and then again comes back on.

My sensor is good, the fuses are good, and the spark plugs are new.

It says a small leak but where could the leak be?

most leaks are so small that you can not see and need to have a special tools to help you and locate them
the use of a smoke machine proven very helpful in detecting all leaks

MLI comes on and remains on while driving. Took it in and the did a diagnostic test and said they thought it needed the fuel system serviced and new plugs. So they put 8 new platinum plugs and did a 3 step fuel injection service. I drove it for 5 miles and light came back on. They took it and reset it and light came back on. Now they are suggesting it news new fuel injector, but said to drive the truck for a while to let chemcials run through they put in. Any ideas about the problem would be appreciated. Thanks. Carla

go to autozone and have them scan it and bring the codes back here, because i dont think they are telling you everything

it sounds, without knowing if you have a distributor, that you have a bad injector in cylinder one, now before doing that I would put new spark plug wires on it if you havent already.(that might have something to do with it) . please respond asap

Have a '01 dakota ext cab 4wd with 3.9 my MIL light has come on. Truck runs fine under 40 mph, but once over 40mph MIL starts to flash and truck stalls and has no power. Any ideas? Also my cruise control light comes on when pushed, but I can't set the cruise. Could this be a related problem?

Hi:
What you need to do is have the computer scanned to identify what codes are stored. They will direct you to the problem. Most parts stores will do it for free.

Let me know what you find.
Joe

Engine Mechanical problem
2001 Dodge Dakota V8 Four Wheel Drive Automatic 90000+ miles

My truck has been idling oddly for some time now. It usualy occurs at low speeds but mostly when stopped or just starting the truck. It used to idle at around 1000rpm but now will jump to about 2000rpm at times. Just recently I replaced the TPS becuase of the check engine light but still have the problem. I see from researching most say there is a vacuum leak. Is that the best bet? If so how do I check?

Has the check engine light come on? Also, yes it could be a vacuum leak. Also, check fuel pump pressure.

Let me know what you find.

Yes my check engine light was on but has not come back since I replaced the TPS (about a 2 weeks ago). I'm sorry for being dumb here but how do I check the fuel pressure?

After looking through the online manual from mitchell1, I saw that I did NOT change the TPS I changed the Idle Air Control Motor. When I got the error code I was told to get something that sounded like a mix of the TPS and IACM. When I was looking around for the replacement there were a mixture of pictures and name for both so I figured different people called called the same part by a different name. But the diagram shows me that I CHANGED THE IACM NOT THE TPS.

Also I found a very helpful video on 2carpros.com on checking for fuel pressure (You may have seen it. Just Kidding). Anyway, another thing I can't seem to find in the manual is the fuel pressure levels.

For anyone following that hasn't seen my other post. I fixed my rough idle with a good throttle body cleaning and a quick trim of a vacuum line on the right of the throttle body! Hope it helps yall and thanks to the great people at 2carpros!!!!

ALSO, I bought a guage and did a fuel test. Regular pressure should be btw 47 and 51 psi. Mine was at 42psi when key on but engine off and 50psi with engine on. I was not able to test the fuel pressure regulator becuase I cannot drop the gas tank at this time. since it along with the fuel filter are above the tank :-(

curious to if anyone knows what is the resistance supposed to be for the plug wires, because the check engine light is on saying there is a misfire in one of my cylinders again. i have already replaced all the wires, spark plugs, and distribitor cap once, and the timing is correct as well. just curious so i can check the wires to check and see if they are working correctly or not.

[quote:69a8309e7d="2000chevyman"]Engine Performance problem
2001 Dodge Dakota 6 cyl Two Wheel Drive Manual 178000 miles

curious to if anyone knows what is the resistance supposed to be for the plug wires, because the check engine light is on saying there is a misfire in one of my cylinders again. i have already replaced all the wires, spark plugs, and distribitor cap once, and the timing is correct as well. just curious so i can check the wires to check and see if they are working correctly or not.[/quote:69a8309e7d]


Hello,

If I am not mistaken I believe it is 1000 ohms per inch.

Is it the same cylinder misfiring?

Other causes of a misfire.....

a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
_________________

no its not the same cylinder and when i replaced everything my check engine light has been off for about 8 or 9 months now and has just recently come back on with another cylinder misfire other than the 2 originally before everything was replaced

Other causes of a misfire.....

a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

The truck is having a hard time switching gears, which seems to be causing the truck to work too hard. It is buring fuel like crazy, and now it's over heating. The "check engine" light went on. We did a transmission tune up, but the light only turned off for a day or two after that. What could the issue(s) be?

It sounds like two different issues. First, as far as the engine temp, make sure the coolant is full and clean. Also, has the thermostat ever been replaced?

As far as the transmission, if it isn't shifting soon enough, it could be over reving the engine causing it to overheat.

Now the trans, there are a few things. It could be the trans countrol module (TCM), a bad shift solenoid, or it may be time for an overhaul. Can you describe what it is doing?

Joe

Like my screen name says I am an Idiot when it comes to vehicles I just drive it, so I can try to describe what is going on, but I don't know the car Lingo.

Any time that I am driving on the street it take a while for the car to actually get into another gear, it's revving for sure trying to change gears. When I am on a highway or freeway driving at a steady fast pace it seems to be easier on the vehicle because all of the revving stops and it's a bit smoother. A friend said that it seems as though the vehicle is driving in 1st or 2nd gear the whole time. I don't know what any of it means. It might be easier to just throw it over a cliff, and get a new one... (Just kidding). Thanks for your help I really appreciate it. Is there a physical address that I can send a donation to? I'm old skool none of this online payment stuff.

Recently my truck has started roughly. At first warming up the rpms will go up then settle down, go up settle down while driving, Today seemed to be running fine when I came to several hills and coasting down hill rpms would go to nothing and the truck would shut off. Put it in neutral, started back up to next coasting place. Then the check engine light came on.

Read and record the diagnostic fault codes. Chrysler makes that real east to do yourself. Cycle the ignition switch from "off" to "run" three times within five seconds without cranking the engine, leave it in "run", then watch the numbers show up in the odometer display.

2001 Dodge Dakota. 69,000 miles. The check engin light came on and I read the code as "oxygen sensor". After a couple weeks the light went off. Was it a short? Do I need to replace the sensor? Thanks

not sure how similar they are - but my 2001 Monte Carlo LS did the same thing. It turned out to be a loose gas cap - actually it was cross threaded. I reseated the cap, and after about an hour of driving the light went off.

In most GM cars if the gas cap is loose or the the electrical system gets wet, the check engine light will go on and then after its fixed or the cap is on tightly what have you, it should go off. Many things can cause this light to go on, but if you came up with the code o2 sensor ( oxygen sensor ) then you should check and replace the o2 sensor. but also check and make sure the gas cap is secure.

Always says check to see if gas cap is on tight or there maybe a vacuum leak. this is the 3rd time in the last 18 months and I have replaced cap twice. My mechanic cannot determine where the vacuum leak is and also do you check for one. I'm trying to keep from taking it the dealer ship. Also vehicle runs fine.

You need to find a mechanic that has a "smoke machine" this is a machine that can introduce smoke into the system which will then leak out wherever the leak is.
You might also have a purge solenoid that has gone bad. This is sometimes that cause of your problem.

ck the dealer for bullitins to

look under the truck at the Charchol Canister it has a few vaccume lines coming and going and that is sensitive if any are dry rotted it will cause a leak in the fuel pressure system and throw a MIL light

I had the same thing in my 99 sport. I checked the char can and noticed I had a crack on the housing for my gas tank that wasn't very big but after throwing some epoxy on it. FIXED. Moral of story... Look around the canister and gas tank housing for any cracks. Mine was only about an inch big.