Engine choices are 5.0L, 5.7L and 7.4L gas, and 6.5L diesel. No 5.3L engine.
For hard starts, have fuel pressure checked. If over spec, suspect a leaking fuel pressure regulator.
For misfire, replace spark plug wires if original (use ACDelco only), check distributor cap for oxidized terminals and carbon tracking, rotor for burned contact tip.
I retrieved a code P401 from our 2000 Pontiac Grand Prix (3.8L non turbo) with a scan tool and software I recently purchased.
P401- EGR flow insufficient
I reset the trouble code on the computer. The vehicle has been driven 4 days and the code has not reappeared yet. Could this be something as simple as removing the EGR and cleaning?
Also, unrelated - but what is the normal output voltage range for 02 sensors? My scan tool software lit up a red background around my bank1 o2 sensor reading when it was in the .8 voltage range. Is normal +/- 0.5 volt?
DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient
Circuit Description The PCM tests the EGR system during deceleration by momentarily commanding the EGR valve to open while monitoring the Manifold Absolute Pressure (MAP) sensor signal. When the EGR valve is opened, the PCM should see a proportional increase in MAP. If the expected increase in MAP is not seen, the PCM notes the amount of error that was detected and adjusts an internal fail counter towards a fail threshold level. When the fail counter exceeds the fail threshold level, the PCM will set DTC P0401. The number of test samples required to accomplish this may vary according to the amount of detected flow error.
Use this routine:
- Remove the EGR valve. - Visually and physically inspect the following items: Pintle, valve passages and the adapter for excessive deposits or any kind of a restriction. EGR valve gasket and pipes for leaks. Clean or replace EGR system components as necessary.
- Remove the EGR inlet and outlet pipes from the exhaust manifold and the intake manifold. - Inspect the manifold EGR ports and the EGR inlet and outlet pipes for a blockage caused by excessive deposits, casting flashing or other damage.
Upstream O2 sensor voltage should vary fairly rapidly between about 200mV and 800mV. Downstream sensors should hold fairly steady around 500mV.
So i took off the plastic engine shield to look for either a short in the cable, or the connection to the sensor is loose.
nothing looked loose, and i didn't see any shorted wires but i didn't pull down the sheath to check all the way down. but i jiggled the wires anyway.
these wires are on the passenger side of the car. the air filter housing is on the driver's side, so the wires don't run anywhere near it.
i still don't know why opening the air filter unit fixed the problem. and i still don't know why the code pops up only when i have the A/C on. but i did notice that near the air filter housing are the acceleration and cruise control cables. i jiggled (pulled/pushed) them as well.
anyway, no more problems with the check engine light coming on. i drove 200miles with the a/c in 90+ degree heat w/o a problem.
now how do i remove the ocv filter to get it cleaned/replaced? i have no room for the rachet to move. the alternator is in the way. if i remove the alternator, then i also have to remove the fan belt. how easy is it to put back the fan belt on a 2002 prizm if you are parked on the street?
but I can tell you that putting a new fan belt on a 2000 explorer V8 is probably impossible with a ratchet and socket, because I failed at it. I have since spent the $50 on a belt tensioner adjustment tool, which looks like a lawn mower blade with bolt head hexes cut into it, because I don't relish having a multibuck flatbed tow if I shed a belt.
if you have similar concerns, it should fully depend on whether you have plenty of room to get to your belt tensioner, and plenty of swing area to tweak it to limit and slip the belt on. notice that old belts are stretched, and that it's thus a whole lot easier to get the old belt off than to get the same belt back on, and a new one is harder still.
I just got a 88 Chev Caprice with Carb V-8 "h" engine. I get a check engine light , mostly at speeds over 55 and it is intermittent. I changed the PCV valve, air filter and the one O2 sensor I found on the left side of the engine. What else is there? Another O2 sensor? Does this thing have a computer readout or was it too early in emissions to have one? The car has 63000 miles and was never driven over 50 mph (my 90 year old mom) til I got it. Thanks for the help...I just knew the O2 sensor was going to fix it...not.
capt2, Why did you replace the O2 sensor?? Let me guess, because someone told you that when the light comes on, it is always the O2 sensor. Well, I guess you found out the hard way, that it is rarely the O2 sensor. Anyway, to your problem..... First, clear the trouble codes, by disconnecting the battery for at least 30 seconds, then roadtest and see if the light returns. If it does, then retrieve the trouble codes. This page gives the procedure. Then on the same page, scroll down to your engine. In your case, I am pretty sure it is 86-88 5.0L Carburetor, VIN H. That link will take you to the codes list.
Thanks for the expert advice, you are correct on the engine type. Have a minor problem though...the code I get is 12 and the chart starts at 13????? I did let it cycle through a few times and each time it says 12. Each time I cut the engine off the light goes away and comes on after about 5 minutes of high speed (over 55) driving. It doesn't come on at city speeds, but does stay on when you come off the interstate. Thanks. PS The test system worked as advertised but the 12 pin DLC was a little different. The entire top row had pins and the bottom row had none at all???
Don't worry about the rest of the pins on the connector, as long as there are the A & B pins, that is all we're concerned about. The remainder of the pins are for various other applications that may not be used on your vehicle.
The code 12 is normal and nothing that we can use. It will always show up. What you need to do is to drive the vehicle until the light comes on. While the light is still on, find somewhere safe to pull over and run the test. Print out the page with the test on it and bring it with you. (It's ok, it is mine.) Since it is coming on at highway speeds, then more than likely, it is an EGR problem, but without the codes, we cannot be certain. One of the reasons that I say it may be an EGR problem is because one of the symptoms of an EGR problem is the light coming on at higher, sustained rpms and long pulls, such as climbing a long hill. If you are mechanically inclined, you can purchase an EGR gasket (about $4) and pull the EGR and check to see how carbon plugged it is. Clean all of the carbon out of it and the passage in the manifold (A heavy guitar string on a drill motor works real good for running thru the manifold passage to open up the port). Then re-install the EGR and roadtest again. If the light doesn't come on, you know that was the problem. Cost of the fix to you would be a couple hours time and under $10 for parts. If it isn't the fix, then you are out a little time and the EGR gasket needed replacing and inspected anyway. : ) With the age of the vehicle, it is very common.
CODE 12, NO DISTRIBUTOR REFERENCE PULSES CIRCUIT DESCRIPTION Code 12 means the ECM is "ON" and sees no reference pulse from the distributor. This is a normal code with the ignition "ON" and engine not running,and is used for the verification of ECM operation during the "Diagnostic Circuit Check". Code 12 is not stored and will only flash when the fault is present. With the engine running, Code 12 could mean an open or ground in the distributor reference circuit. Code 41 will appear with Code 12 if the engine is running with no distributor reference signal. If the problem clears, Code 41 will store.
You say check the system while the light is on. Can I use the paper clip on the grd and test pin while the engine is running? Will it go to the codes without turning off the key (which will kill the light)?? Also I'm not familiar with where the EGR is, don't mind getting dirty when I do.LOL. Would it be better to just change out the EGR or would that be a waste? Thanks.
No, do not check the codes with the engine running. You will need to shut it off, then turn the key on and check the codes.
I checked and the gaskets you need are Fel-pro 70950 and 2 are required. They should run about $3 each.
After looking, you may have trouble getting the EGR out without removing the carberator. If you cannot pull it without removing the carb, then you will need a carberator gasket too, but this is an area where you really should have someone do it, if the carb needs to be removed. Fuel will be present and that is a dangerous thing.
I wouldn't change any parts right now. You can't be sure that the EGR is the problem, so you would only be throwing money away. Here is some info to help. It is a pdf file and requires Adobe Acrobat reader.
They had to ship the gaskets from another store and will be there tomorrow. Will take a look and see if I can get it out then. If it is such that I can't what is the real downside of just leaving it alone? This is a $750 car that I only kept to drive to work because it gets 24+ mph on the highway. Thanks for all your help. Bill.
Fuel economy will suffer if the light problem isn't taken care of. But as I said, you need the trouble code of what is turning on the light. That will help determine what the problem is and work toward repairing it. One thing you might try, if there is an AutoZone near you, they can hook up to it with a scanner and maybe they can pull some codes from it.
My car will be illegal to drive in New York State next year unless Saturn can fix the problem. They have had it 11 times on this all dealer maintained car. The problem started at 12990 miles 2 days after warranty and car now has 17600 miles. I may have to give this car away to charity. Following is a long saga of dealing with P0442 code on a 2000-Saturn SL2:
Saturn has yet to fix this vehicle with reliability or credibility; the manufacturer doesn't seem to have the answer, either. Problem started 2 days after 3-year warranty was up: Last visit, car was in shop for three days. Car has never been to an outside mechanic. Notice repeat part replacements on this low mileage car. Come 4/1/2005 this car will not pass inspection in New York State. In fairness, Saturn has not charged me, but I can't even get another dealer to take this car as a trade-in.
Any suggestions on what Saturn mechanics failed to do? They claim car passes pressure tests and smoke tests -- that the car is mechanically sound -- that there is no leak.
George
Date Miles Part and Part serial number and job
>04-Nov-2002 10622 PCM Engine Coolant Temperature Sensor 21025106 Replace >04-Nov-2002 10622 Connector 12117087 Repair ALDL/DLC/SES >02-Jun-2003 12875 State Inspecrion >10-Jun-2003 12996 None No Repair >17-Jun-2003 13113 Seal-F/PM 21008100 Replace Fuel Pump Seal >07-Jul-2003 13339 Solenoid, Evap. Emiss. Cannister Purge 10293954 Replaced Valve ASM >07-Jul-2003 13339 Solenoid, Evap. Emiss. Cannister Purge 21007370 Replaced Tank ASM >23-Jul-2003 13509 Fuel Vapor Pressure Sensor 16238399 Replaced >11-Aug-2003 13773 Solenoid, Evap. Rmiss. Cannister Purge 21008461 Replaced Solenoid >16-Sep-2003 14242 PCM Engine Coolant Temperature Sensor 21025106 Replace >21-Oct-2003 14605 Tank ASM 21007370 Replace Fuel Tank >21-Oct-2003 14605 Cannister 17098073 Replace Fuel Vapor Cannister >21-Oct-2003 14605 Valve ASM 10293954 Replace Vaklve for Evap. Emiss Cannister Vent Solenoid >21-Oct-2003 14605 Pump Kit 21015152 Replace in tank Fuel Pump >06-Jan-2004 15467 Fuel Tank Filler Neck 21008388 Replace fuel tank filler neck >04-May-2004 16672 Engine Control Module (PCM/ECM) 21025128 Replace Computer >14-Jun-2004 17217 PCM Engine Coolant Temperature Sensor 21025106 Replace >14-Jun-2004 17217 Fuel Tank Cap 22660002 Replace >27-Jul-2004 17567 Fuel Vapor Pressure Sensor 16238399 Replace
The only thing I can think of is check the wiring between the Fuel Vapor Pressure Sensor 16238399 and the PCM, it looks to me like its getting an erroneous reading, the computer only knows what the sensors are telling it. This is the only thing I can think of. Good luck
or someplace else. have you called the zone office and asked those folks for help yet with the car?
// delayed // just had a brainstorm of sorts. what does a voltage read on the input to the computer module show? if the sensor voltage is in range, you could have a one-channel a/d chip failure on the computer. also I would use a toothpick to apply some Caig De-Ox-It to the contacts of the computer input connector, and pull and replace that connector several times, in case this is an oxidized contact issue. De-Ox-It is availiable at specialized electronics parts suppliers, by internet order you can get it at www.tubesandmore.com . fantastic stuff.
Hi, I bought a 2003 Honda Civic Ex coupe, 2 Door , 5 Speed Manual with 7000 Miles on it. The car had its first service at 4500 Miles. Now it has around 8100 Miles. The dealer said the next service is due after 10,000 miles.
But,Yesterday I got the maintenance required Light.I checked the fuel tank cap it is fine(basic trouble shooting). Can any one tell me what could be the problem or give me more trouble shooting tips?
I Still have warrenty on it. Can you give me suggestions , so that I can ask them to change the parts if required.
The check engine light was on about three months ago, but then went out after three days when I was going to bring in to the dealer to check it out. Then it came on about three days ago but went out again today. Should I still bring the car in to check it out? I detected no appreciative change in car performance during these times. Can I wait for my next service to have it checked out?
Just bought a 2001 VW Beetle w/ base 4-cylinder engine, and the CEL came on. Local knowledgeable mechanic (NOT VW dealer) ran codes, then replaced heat sensor and speed sensor. Now the CEL comes on only when engine is cold (some roughness noted) then goes out when it warms up and engine smoothes out(no hard code noted). Any ideas???
rhmass, If the light is out, then the problem has reset itself. It will be alright to run without any problems, provide the light stays out. A solid light on means that there is an emissions problem somewhere. A blinking check engine light means that there is a catastrophic failure and continuing to run the vehicle will result in damage to the engine or drivetrain.
That being said, you should be ok to run the vehicle. If the light comes on again, a stop at an AutoZone and they can pull the trouble codes. Once you have the trouble codes, we can help you decipher them to find the cause. Don't let them sell you anything.
fastpaul, What was the trouble code number that the mechanic got? Did he replace the "heat sensor", which I am assuming to be the temp or cold start sensor, with an OEM sensor?? If he didn't, that is most likely your problem. The engine uses a temp sensor for cold starts, to keep it running when cold. If the sensor is not OEM, then it will send an erroneous signal to the PCM and it will send an incorrect fuel mixture.
...light came on and was most surely due to the missing gas cap that seemed to have been stolen, destroying the tether. That left me looking for a solution on a Sunday morning, with the Saturn dealership closed. I ended up going to a nearby NAPA store, asking for a gas cap for this 2003 Vue. There were none listed in the NAPA catalog, but the counter man found me a reasonable alternative that was listed for other 2003 Saturn vehicles, the Balkamp 703-1643 locking fuel cap. On Monday I contacted a Saturn service writer who told me I would have to have Saturn turn out the light, because it would not do it automatically in response to a new gas cap. By late Tuesday the light had extinguished automatically, contrary to what I was told. If there is a question here left to be asked, it must be: Will the code that had been stored just disappear with the light going out, or will it disappear after X number of engine use cycles, or must it be removed by a technician with proper electronic tools in hand?
will probably be gone after a certain number of start cycles (50 sticks in my mind for some codes). Even if the code stays in the computer, it would cause no problem as long as the cause of the code has been corrected.
If the system works like mine on a 98 LeSabre -- it checks for leakage in the fuel tank system by drawing a vacuum or pressuring slightly and then testing how long that change in pressure lasts. It only does this when the engine is between two temperatures when started. As in drive 3 miles. Stop for coffee. Restart. I think the temp had to be 130 degrees but below a certain temp.
When that happened and you restarted the engine the light probably was out within a minute. That's what happened with mine when the cap was loose.
The code will remain stored indefinitely as a inactive code. If the tech checking the vehicle later on is using a Tech2 scanner (OEM), then it will show the code as an inactive code and when it was tripped and how many counts that it logged it. So it shouldn't be an issue. If the tech is using a generic scanner, then it will probably show the code. General practice though, is to log the codes, then clear all codes and then roadtest the vehicle. If the codes come back, then you know it is a current code.
imidazol97 and 0patience: Many thanks for the added info. My daughter in college has the car with her. Next on the agenda will be the soon expected message to bring the Vue in for the recall on the rear suspension.
Thanks so much for your reply to my question. I am sure many posters appreciate your willingness to share your knowledge to those of us less technically inclined.
As a point of interest, the Vue was taken in to a Saturn dealership for a software update programming which had apparently been a recall item some months ago that I had not heard about until now. No mention was made at all about a lingering code concerning the gas cap episode. A check back with NAPA brought forth the info that the gas cap they sold me is indeed the proper one for a 1993 Vue, even though their cataloging does not list it as such. Aaaah! The trials a tribulations...
I have a '99 Maxima SE. I brought it to Midas for brakes and a battery. When I got the car back the Service engine soon light was on. Is this a coincedence or did Midas cause the problem?
First, I just have to ask this question, because it is begging to be asked............
Why would you go to a muffler shop for brakes and a battery?? That's like going to a tranny shop for a tune up.
Without knowing what the troublecodes are, it would be tough to even guess if it could be something they did or a coincidence. Is there an AutoZone near you? If there is, they may be able to pull the troublecodes and tell you what numbers they are. Don't let them sell you anything, just get the codes. ; )
Once we know what the troublecodes are, then we can determine if they are related to anything that was done. Probably not, but won't know until codes are retrieved.
My CEL came on on my 99 Mazda Protege. It has about 65K miles on it. My mechanic told me it has something to do with the EVAP sensor and that it has to be replaced. I was just curious if anyone has any experience with this and if so, what did you do about it.
Any one of the below list things can cause this trouble code.
The best thing I can tell you is to check the fuel cap (just a common starting point), make sure the gasket is good and intact, check that all vacuum hoses and connections are good, then clear the trouble codes, road test and re-check teh troublecodes. If the code returns, then you will need the diagnostic chart and a scantool to diagnose the problem.
My two cents worth, based on experience with a 1998 Nissan Pathfinder: Consider buying a brand new gas cap for the car and install it. I discovered that NAPA sells very good ones. It's not a lot to spend on a test to see if that cures the CEL being on. After perhaps several days of on/off cycles of the engine, including some driving time each cycle, the light may go off due to the new cap maintaining proper tank pressure. If this fails to extinguish the glow, you'll need professional diagnosis.
Thanks for all the input. I actually tried that and it didn't work, so I took it back to the mechanic and they found out that the actual sensor that controls the bleeding from the fuel tank to the engine needs to be replaced - someting to do with the vaccum I believe (or at least that was my understanding) From what I understand the part isn't too expensive and doesn't take too long to install.
It's funny that this all happened right AFTER I put a new tank of gas into the car from the same station that I have been getting gas for for the past 5 years. Just my luck I guess...LOL.
My 2000 Volvo S40's engine light is on. When driving at low RPMs, the car would start to bog down, lose power and eventually stall. When I'm at a stoplight it often stalls as well. This is usually after a good 10 minutes of driving. I brought it to the dealer and they said the atmospheric sensor was bad and replaced it. It worked for a day or so, but now the car exhibits the same problem.
Does the atmospheric sensor sound like BS? I've never heard of it before. Also, we asked that they leave us the old parts, but they conveniently "forgot".
I have got exactly the same issue (P0171) on my 2000 toyota corolla with 53K miles on it. I have been told to replace the oxygen sensors, but I am not sure if that is the root cause of the problem. Can you please let me know if this problem is fixed on your car and what did u do to get it totally fixed. (I usually fill gas from Chevron but the check engine light came after I filled the gas from some gas station at a rest area on highway)
Would really appreciate if I can get help on this.
Don't believe everything you're told. The O2 sensor is reporting a lean fuel condition. Start by checking for any cracked, broken or disconnected vacuum hoses. Also check the ducting to the throttle body for any damage. If all's ok, have the fuel pressure checked.
Have '89 4R with V-6, 5spd. Great body. Compression is 165psi and hot idle oil pressure is 30psi.
THIS IS MY SORRY TALE:
NO CHECK ENGINE OR CODES FROM ECU.
Started to bog at low rpm. Replaced fuel pump; cold start injector, diaphram are ok. Replaced ALL SIX fuel injectors (They were cracked and leaking), plugs, plug wires, dist cap, rotor.
Is now burning rich; runs good when cold, then black smoke out tailpipe when it warms up and cylinders 5&6 periodically misfire. Plugs in 1-4 cyliners are black, but not oily.
Have put $3,500 into it. Mechanic is going to check sensors and ecu with ohm meter. He seems in over his head. HELP!
I had and accident and have had no hood on my car for about a week, allowing the engine to get wet, as it has been rainin. I then had a bliking check engine light that occurred from a cold start, and I let it sit for the weekend. Now it's a solid light, and I'd like to check the ECU code, but I'm not sure where it is. One site mentions it's in the passenger side footwell under the carpet. Can you give me some guidance?
on last week (2004 Ram 1500 Hemi) and the dealer flashed some module...it worked for four days and the light came back on...this time they replaced same module, got truck back today, light is out so far...I asked why they did not replace it earlier, they said they had to try flashing the software first because it had a high probability of properly correcting the problem...this makes sense, even tho it took an extra trip to fix it in my case, if over half the flashing fixes the problem, then try the simple repair first...I might be upset if they made me flash it four or five times prior to replacement, but to try it once and then replace it immediately if it does not work is fair enough IMO...now let's see if the light comes on in the next week...:):):):)
I'm new to the web site and I own a 2002 Jetta I have 44000 mile on the car and it has been serviced by VW. My check enging light came on and the code from a code reader is P0673 unknown power train DTC. I would like to know if anyone knows what this means and how to fix it?
Do you know there are 5 engine options for that vehicle?
I have to assume it is a diesel, because the only engine that shows a trouble code P0673 is the diesel and that trouble code is a glow plug cylinder #3 malfunction.Check for an open or shorted circuit to the #3 cylinder glow plug and test the glow plug.
Today I was driving to the grocery store and as I was merging onto the freeway this lady wouldn't let me in so I had to press on the gas to speed up and cut in front of her and the rpm's went all the way into the red zone - to the 6 or 7. two seconds after, the check engine light turned on and my car felt like it was chugging for the rest of the way to the grocery store. especially when i would come to a stop sign . After I went grocery shopping, I turned my car back on and the light was still on, but it didn't chug on the way home. I am scared to drive my car now I mean I don't want it to break down while I'm on the freeway. Does anyone know if the light went on because some gas might have got into the engine? If so, will it leak back out or do I have to take it to the dealer???
I just took it to the dealer and now this happens. The last 2 times I took it to the dealer, other things have broken too, including the air conditioning exploding and Honda having to pay for the $4000 damage it caused, as well as a leak in some hose. Is this just a coincidence or is the dealer messing up my car so they'll make more money!PLEASE EMAIL ME bunnywillgetyou@yahoo.com
Comments
For hard starts, have fuel pressure checked. If over spec, suspect a leaking fuel pressure regulator.
For misfire, replace spark plug wires if original (use ACDelco only), check distributor cap for oxidized terminals and carbon tracking, rotor for burned contact tip.
P401- EGR flow insufficient
I reset the trouble code on the computer. The vehicle has been driven 4 days and the code has not reappeared yet. Could this be something as simple as removing the EGR and cleaning?
Also, unrelated - but what is the normal output voltage range for 02 sensors? My scan tool software lit up a red background around my bank1 o2 sensor reading when it was in the .8 voltage range. Is normal +/- 0.5 volt?
Circuit Description
The PCM tests the EGR system during deceleration by momentarily commanding the EGR valve to open while monitoring the Manifold Absolute Pressure (MAP) sensor signal. When the EGR valve is opened, the PCM should see a proportional increase in MAP. If the expected increase in MAP is not seen, the PCM notes the amount of error that was detected and adjusts an internal fail counter towards a fail threshold level. When the fail counter exceeds the fail threshold level, the PCM will set DTC P0401. The number of test samples required to accomplish this may vary according to the amount of detected flow error.
Use this routine:
- Remove the EGR valve.
- Visually and physically inspect the following items:
Pintle, valve passages and the adapter for excessive deposits or any kind of a restriction.
EGR valve gasket and pipes for leaks. Clean or replace EGR system components as necessary.
- Remove the EGR inlet and outlet pipes from the exhaust manifold and the intake manifold.
- Inspect the manifold EGR ports and the EGR inlet and outlet pipes for a blockage caused by excessive deposits, casting flashing or other damage.
Upstream O2 sensor voltage should vary fairly rapidly between about 200mV and 800mV. Downstream sensors should hold fairly steady around 500mV.
nothing looked loose, and i didn't see any shorted wires but i didn't pull down the sheath to check all the way down. but i jiggled the wires anyway.
these wires are on the passenger side of the car. the air filter housing is on the driver's side, so the wires don't run anywhere near it.
i still don't know why opening the air filter unit fixed the problem. and i still don't know why the code pops up only when i have the A/C on. but i did notice that near the air filter housing are the acceleration and cruise control cables. i jiggled (pulled/pushed) them as well.
anyway, no more problems with the check engine light coming on. i drove 200miles with the a/c in 90+ degree heat w/o a problem.
now how do i remove the ocv filter to get it cleaned/replaced? i have no room for the rachet to move. the alternator is in the way. if i remove the alternator, then i also have to remove the fan belt. how easy is it to put back the fan belt on a 2002 prizm if you are parked on the street?
THX
if you have similar concerns, it should fully depend on whether you have plenty of room to get to your belt tensioner, and plenty of swing area to tweak it to limit and slip the belt on. notice that old belts are stretched, and that it's thus a whole lot easier to get the old belt off than to get the same belt back on, and a new one is harder still.
Why did you replace the O2 sensor??
Let me guess, because someone told you that when the light comes on, it is always the O2 sensor.
Well, I guess you found out the hard way, that it is rarely the O2 sensor.
Anyway, to your problem.....
First, clear the trouble codes, by disconnecting the battery for at least 30 seconds, then roadtest and see if the light returns. If it does, then retrieve the trouble codes. This page gives the procedure.
Then on the same page, scroll down to your engine. In your case, I am pretty sure it is 86-88 5.0L Carburetor, VIN H. That link will take you to the codes list.
Come back and let us know what codes you got.
PS The test system worked as advertised but the 12 pin DLC was a little different. The entire top row had pins and the bottom row had none at all???
The remainder of the pins are for various other applications that may not be used on your vehicle.
The code 12 is normal and nothing that we can use. It will always show up. What you need to do is to drive the vehicle until the light comes on. While the light is still on, find somewhere safe to pull over and run the test. Print out the page with the test on it and bring it with you. (It's ok, it is mine.)
Since it is coming on at highway speeds, then more than likely, it is an EGR problem, but without the codes, we cannot be certain.
One of the reasons that I say it may be an EGR problem is because one of the symptoms of an EGR problem is the light coming on at higher, sustained rpms and long pulls, such as climbing a long hill.
If you are mechanically inclined, you can purchase an EGR gasket (about $4) and pull the EGR and check to see how carbon plugged it is. Clean all of the carbon out of it and the passage in the manifold (A heavy guitar string on a drill motor works real good for running thru the manifold passage to open up the port). Then re-install the EGR and roadtest again. If the light doesn't come on, you know that was the problem.
Cost of the fix to you would be a couple hours time and under $10 for parts. If it isn't the fix, then you are out a little time and the EGR gasket needed replacing and inspected anyway. : )
With the age of the vehicle, it is very common.
CODE 12, NO DISTRIBUTOR REFERENCE PULSES
CIRCUIT DESCRIPTION
Code 12 means the ECM is "ON" and sees no reference pulse from the distributor. This is a normal code with the ignition "ON" and engine not running,and is used for the verification of ECM operation during the "Diagnostic Circuit Check". Code 12 is not stored and will only flash when the fault is present. With the engine running, Code 12 could mean an open or ground in the distributor reference circuit. Code 41 will appear with Code 12 if the engine is running with no distributor reference signal. If the problem clears, Code 41 will store.
You will need to shut it off, then turn the key on and check the codes.
I checked and the gaskets you need are Fel-pro 70950 and 2 are required.
They should run about $3 each.
After looking, you may have trouble getting the EGR out without removing the carberator. If you cannot pull it without removing the carb, then you will need a carberator gasket too, but this is an area where you really should have someone do it, if the carb needs to be removed. Fuel will be present and that is a dangerous thing.
I wouldn't change any parts right now.
You can't be sure that the EGR is the problem, so you would only be throwing money away.
Here is some info to help. It is a pdf file and requires Adobe Acrobat reader.
But as I said, you need the trouble code of what is turning on the light. That will help determine what the problem is and work toward repairing it.
One thing you might try, if there is an AutoZone near you, they can hook up to it with a scanner and maybe they can pull some codes from it.
Following is a long saga of dealing with P0442 code on a 2000-Saturn
SL2:
Saturn has yet to fix this vehicle with reliability or credibility;
the manufacturer doesn't seem to have the answer, either. Problem
started 2 days after 3-year warranty was up: Last visit, car was in
shop for three days. Car has never been to an outside mechanic.
Notice repeat part replacements on this low mileage car. Come
4/1/2005 this car will not pass inspection in New York State. In
fairness, Saturn has not charged me, but I can't even get another
dealer to take this car as a trade-in.
Any suggestions on what Saturn mechanics failed to do? They claim car
passes pressure tests and smoke tests -- that the car is mechanically
sound -- that there is no leak.
George
Date Miles Part and Part serial number and job
>04-Nov-2002 10622 PCM Engine Coolant Temperature Sensor 21025106 Replace
>04-Nov-2002 10622 Connector 12117087 Repair ALDL/DLC/SES
>02-Jun-2003 12875 State Inspecrion
>10-Jun-2003 12996 None No Repair
>17-Jun-2003 13113 Seal-F/PM 21008100 Replace Fuel Pump Seal
>07-Jul-2003 13339 Solenoid, Evap. Emiss. Cannister Purge 10293954 Replaced Valve ASM
>07-Jul-2003 13339 Solenoid, Evap. Emiss. Cannister Purge 21007370 Replaced Tank ASM
>23-Jul-2003 13509 Fuel Vapor Pressure Sensor 16238399 Replaced
>11-Aug-2003 13773 Solenoid, Evap. Rmiss. Cannister Purge 21008461 Replaced Solenoid
>16-Sep-2003 14242 PCM Engine Coolant Temperature Sensor 21025106 Replace
>21-Oct-2003 14605 Tank ASM 21007370 Replace Fuel Tank
>21-Oct-2003 14605 Cannister 17098073 Replace Fuel Vapor Cannister
>21-Oct-2003 14605 Valve ASM 10293954 Replace Vaklve for Evap. Emiss Cannister Vent Solenoid
>21-Oct-2003 14605 Pump Kit 21015152 Replace in tank Fuel Pump
>06-Jan-2004 15467 Fuel Tank Filler Neck 21008388 Replace fuel tank filler neck
>04-May-2004 16672 Engine Control Module (PCM/ECM) 21025128 Replace Computer
>14-Jun-2004 17217 PCM Engine Coolant Temperature Sensor 21025106 Replace
>14-Jun-2004 17217 Fuel Tank Cap 22660002 Replace
>27-Jul-2004 17567 Fuel Vapor Pressure Sensor 16238399 Replace
// delayed // just had a brainstorm of sorts. what does a voltage read on the input to the computer module show? if the sensor voltage is in range, you could have a one-channel a/d chip failure on the computer. also I would use a toothpick to apply some Caig De-Ox-It to the contacts of the computer input connector, and pull and replace that connector several times, in case this is an oxidized contact issue. De-Ox-It is availiable at specialized electronics parts suppliers, by internet order you can get it at www.tubesandmore.com . fantastic stuff.
I bought a 2003 Honda Civic Ex coupe, 2 Door , 5 Speed Manual with 7000 Miles on it.
The car had its first service at 4500 Miles. Now it has around 8100 Miles. The dealer said the next service is due after 10,000 miles.
But,Yesterday I got the maintenance required Light.I checked the fuel tank cap it is fine(basic trouble shooting).
Can any one tell me what could be the problem or give me more trouble shooting tips?
I Still have warrenty on it. Can you give me suggestions , so that I can ask them to change the parts if required.
Thanks
Smith.
If the light is out, then the problem has reset itself. It will be alright to run without any problems, provide the light stays out.
A solid light on means that there is an emissions problem somewhere. A blinking check engine light means that there is a catastrophic failure and continuing to run the vehicle will result in damage to the engine or drivetrain.
That being said, you should be ok to run the vehicle. If the light comes on again, a stop at an AutoZone and they can pull the trouble codes. Once you have the trouble codes, we can help you decipher them to find the cause. Don't let them sell you anything.
fastpaul,
What was the trouble code number that the mechanic got?
Did he replace the "heat sensor", which I am assuming to be the temp or cold start sensor, with an OEM sensor??
If he didn't, that is most likely your problem.
The engine uses a temp sensor for cold starts, to keep it running when cold. If the sensor is not OEM, then it will send an erroneous signal to the PCM and it will send an incorrect fuel mixture.
If the system works like mine on a 98 LeSabre -- it checks for leakage in the fuel tank system by drawing a vacuum or pressuring slightly and then testing how long that change in pressure lasts. It only does this when the engine is between two temperatures when started. As in drive 3 miles. Stop for coffee. Restart. I think the temp had to be 130 degrees but below a certain temp.
When that happened and you restarted the engine the light probably was out within a minute. That's what happened with mine when the cap was loose.
2014 Malibu 2LT, 2015 Cruze 2LT,
Why would you go to a muffler shop for brakes and a battery??
That's like going to a tranny shop for a tune up.
Without knowing what the troublecodes are, it would be tough to even guess if it could be something they did or a coincidence.
Is there an AutoZone near you? If there is, they may be able to pull the troublecodes and tell you what numbers they are. Don't let them sell you anything, just get the codes. ; )
Once we know what the troublecodes are, then we can determine if they are related to anything that was done. Probably not, but won't know until codes are retrieved.
Thanks
The best thing I can tell you is to check the fuel cap (just a common starting point), make sure the gasket is good and intact, check that all vacuum hoses and connections are good, then clear the trouble codes, road test and re-check teh troublecodes. If the code returns, then you will need the diagnostic chart and a scantool to diagnose the problem.
Purge solenoid valve malfunction
Cannister drain valve malfunction
Tank pressure control valve malfunction
Charcoal cannister malfunction
clogged air filter
Evaporative gas valve clogged
Evaporative hose damaged
Fuel tank pressure sensor malfunction
ECT (Engine coolant Temp) sensor malfunction
VSS (vehicle speed sensor) malfunction
open or short in wiring harness
poor connection in EVAP system.
It's funny that this all happened right AFTER I put a new tank of gas into the car from the same station that I have been getting gas for for the past 5 years. Just my luck I guess...LOL.
Does the atmospheric sensor sound like BS? I've never heard of it before. Also, we asked that they leave us the old parts, but they conveniently "forgot".
Any other ideas what may be causing this problem?
I have got exactly the same issue (P0171) on my 2000 toyota corolla with 53K miles on it. I have been told to replace the oxygen sensors, but I am not sure if that is the root cause of the problem. Can you please let me know if this problem is fixed on your car and what did u do to get it totally fixed. (I usually fill gas from Chevron but the check engine light came after I filled the gas from some gas station at a rest area on highway)
Would really appreciate if I can get help on this.
Don't believe everything you're told. The O2 sensor is reporting a lean fuel condition. Start by checking for any cracked, broken or disconnected vacuum hoses. Also check the ducting to the throttle body for any damage. If all's ok, have the fuel pressure checked.
THIS IS MY SORRY TALE:
NO CHECK ENGINE OR CODES FROM ECU.
Started to bog at low rpm. Replaced fuel pump; cold start injector, diaphram are ok. Replaced ALL SIX fuel injectors (They were cracked and leaking), plugs, plug wires, dist cap, rotor.
Is now burning rich; runs good when cold, then black smoke out tailpipe when it warms up and cylinders 5&6 periodically misfire. Plugs in 1-4 cyliners are black, but not oily.
Have put $3,500 into it. Mechanic is going to check sensors and ecu with ohm meter. He seems in over his head. HELP!
Dealer diagonsed the following: P0135,P013 & P0133
Two Oxy sensors[$225 each] and Catafold converter[looks like catalytic converter]-$625.
Any suggestions/guidance on taking a second opinion from a different dealer/auto shop.
Please advise.
Thanks
I have to assume it is a diesel, because the only engine that shows a trouble code P0673 is the diesel and that trouble code is a glow plug cylinder #3 malfunction.Check for an open or shorted circuit to the #3 cylinder glow plug and test the glow plug.
I just took it to the dealer and now this happens. The last 2 times I took it to the dealer, other things have broken too, including the air conditioning exploding and Honda having to pay for the $4000 damage it caused, as well as a leak in some hose. Is this just a coincidence or is the dealer messing up my car so they'll make more money!PLEASE EMAIL ME bunnywillgetyou@yahoo.com
I don't want to blow up in my car!