Service Engine Soon === Light On

What's the trick in resetting this signal? I have an 04 Trailblazer with the I6 engine with 41 thousand miles. Regular maintenance, but the light keeps popping up.... Whats the dillio?:shakehead :shakehead :shakehead

What's the trick in resetting this signal? I have an 04 Trailblazer with the I6 engine with 41 thousand miles. Regular maintenance, but the light keeps popping up.... Whats the dillio?:shakehead :shakehead :shakehead

You need to do a search or at least read your owners manual.
Here is the information from your owners manual
Your vehicle is equipped with a computer which monitors operation of the fuel, ignition, and emission control systems.

This system is called OBD II (On-Board Diagnostics-Second Generation) and is intended to assure that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. The check engine light comes on to indicate that there is a problem and service is required. Malfunctions often will be indicated by the system before any problem is apparent. This may prevent more serious damage to your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction.

Notice: If you keep driving your vehicle with this light on, after a while, the emission controls might not work as well, your vehicle's fuel economy might not be as good, and the engine might not run as smoothly. This could lead to costly repairs that might not be covered by your warranty.

Notice: Modifications made to the engine, transmission, exhaust, intake, or fuel system of your vehicle or the replacement of the original tires with other than those of the same Tire Performance Criteria (TPC) can affect your vehicle's emission controls and may cause this light to come on. Modifications to these systems could lead to costly repairs not covered by your warranty. This may also result in a failure to pass a required Emission Inspection/Maintenance test.

This light should come on, as a check to show you it is working, when the ignition is on and the engine is not running. If the light does not come on, have it repaired. This light will also come on during a malfunction in one of two ways:

• Light Flashing -- A misfire condition has been detected. A misfire increases vehicle emissions and may damage the emission control system on your vehicle. Diagnosis and service may be required.

• Light On Steady -- An emission control system malfunction has been detected on your vehicle. Diagnosis and service may be required.

If the Light is Flashing
The following may prevent more serious damage to your vehicle:

• Reducing vehicle speed

• Avoiding hard accelerations

• Avoiding steep uphill grades

• If you are towing a trailer, reduce the amount of cargo being hauled as soon as it is possible

If the light stops flashing and remains on steady, see "If the Light Is On Steady" following.

If the light continues to flash, when it is safe to do so, stop the vehicle. Find a safe place to park your vehicle. Turn the key off, wait at least 10 seconds and restart the engine. If the light remains on steady, see "If the Light Is On Steady" following. If the light is still flashing, follow the previous steps, and see your dealer for service as soon as possible.

If the Light Is On Steady
You may be able to correct the emission system malfunction by considering the following:

Did you recently put fuel into your vehicle?

If so, reinstall the fuel cap, making sure to fully install the cap. See Filling the Tank . The diagnostic system can determine if the fuel cap has been left off or improperly installed. A loose or missing fuel cap will allow fuel to evaporate into the atmosphere. A few driving trips with the cap properly installed should turn the light off.

Did you just drive through a deep puddle of water?

If so, your electrical system may be wet. The condition will usually be corrected when the electrical system dries out. A few driving trips should turn the light off.

Have you recently changed brands of fuel?

If so, be sure to fuel your vehicle with quality fuel. See Gasoline Octane . Poor fuel quality will cause your engine not to run as efficiently as designed. You may notice this as stalling after start-up, stalling when you put the vehicle into gear, misfiring, hesitation on acceleration, or stumbling on acceleration. (These conditions may go away once the engine is warmed up.) This will be detected by the system and cause the light to turn on.

If you experience one or more of these conditions, change the fuel brand you use. It will require at least one full tank of the proper fuel to turn the light off.

If none of the above steps have made the light turn off, your dealer can check the vehicle. Your dealer has the proper test equipment and diagnostic tools to fix any mechanical or electrical problems that may have developed.

Emissions Inspection and Maintenance Programs
Some state/provincial and local governments have or may begin programs to inspect the emission control equipment on your vehicle. Failure to pass this inspection could prevent you from getting a vehicle registration.

Here are some things you need to know to help your vehicle pass an inspection:

Your vehicle will not pass this inspection if the check engine light is on or not working properly.

Your vehicle will not pass this inspection if the OBD (on-board diagnostic) system determines that critical emission control systems have not been completely diagnosed by the system. The vehicle would be considered not ready for inspection. This can happen if you have recently replaced your battery or if your battery has run down. The diagnostic system is designed to evaluate critical emission control systems during normal driving. This may take several days of routine driving. If you have done this and your vehicle still does not pass the inspection for lack of OBD system readiness, your GM dealer can prepare the vehicle for inspection.




You can have the code read at a chain autoparts store and post it here for help.

What's the trick in resetting this signal?

Autozone will read/reset the SES light for you. Of course if the condition still exists, the light will eventually go back on. Like Merlin says, there's 100's of possibilities. Get the code read and post it here.

Joel

Autozone will read/reset the SES light for you. Of course if the condition still exists, the light will eventually go back on. Like Merlin says, there's 100's of possibilities. Get the code read and post it here.

Joel

You DO NOT want to have the code reset!
The DTC (code) is your diagnostic clue to what is wrong with the system.
Have the code read and post it here

You DO NOT want to have the code reset!


The AZ process is to read the code first. No code and they cant sell you any parts. Some will write the code down for you, typically the owner needs to jot it down. There is no harm in recording the code and clearing them. If it's a problem the code will come back.

Joel

The AZ process is to read the code first. No code and they cant sell you any parts. Some will write the code down for you, typically the owner needs to jot it down. There is no harm in recording the code and clearing them. If it's a problem the code will come back.

Joel

I agree, if the light is on solid then were talking sensor or actuator thats out of limits. reseting the code AFTER getting the OBD-II TC is a comon practice, autozone in my area will read the code then take thier scanner back into the store and plug it into a printer and actually print the codes for you, sadly they dont tell what the codes mean , but i bet theres a website that has people that know enough about these trouble codes to head you in the right direction. i hear theres a cool site named www.automotiveforums.com that could be of assistance!

On my 03 tb, I had the "service eng. soon " light on and traced it to the gas cap "seal" . It was getting deterriorated,small cracks from gas. I bought a new cap from O'riellys, but it doesn't have the "don't forget me" plastic attachment line. So,looking at the old cap, I just got a screwdriver and carefully pryed off the seal,turned it around and applied some O-ring lube and put it on with the bad side to the cap. Started the Truck and the light went off immediately. If you open the cap and there is no "vacume hiss" this most likely is the culprit . Now to take the new cap back for a refund..
ps.took the cap back,bought one at the dealer for a few bucks more,why don't they just sell the seal??
light went out,came back on due to some kind of coolant thing. I need to get it re-read and I'll post what it is and try to fix it. And inform everyone what it was. ,since some people just get on here,ask questions,fix it and don't reply what the fix was and don't come back until they are broke again.

debkey's on top of the usual cause of SES lighting up - loose or leaky gasoline filler cap. Gas is so high $$$ these days a lot of people are stealing gas with a siphon or trying. Or it's possible the veh's owner/operator just failed to replace the cap securely after gassing up. Check that first. Inspect cap's underside for clogging or loose/broken innards. Clean or replace (if broken). Place cap all the way onto filler pipe and seat in the detents, turn clockwise for 3 full clicks. If that was the whole problem, usually is, SES light might go out right away or you may need to start, stop, and drive the vehicle enough to allow the PCM to run and log its pressure test on the fuel-EVAP system. If it checks OK, the veh's computer should clear the DTC and turn off the SES. If the SES stays on longer than a day or two, either the fuel-EVAP system has other probs or the PCM isn't completing its work. Best thing at this point is to get it scanned at Auto Zone and look up the codes it pulls, if any. A minor leak code can probably be cleared and that'll be the end of it. However, a major leak code indicates the SES is trying to tell you there's a crack where the filler pipe enters the gas tank or a crack in the tank itself or a stuck canister purge solenoid. Count on one of these further issues being present if you can see gasoline on the ground under the tank or you can smell it. On the extended wheelbase TBs and Envoys you can get GM-paid service under Program 05012 for up to 8 yrs/80K mi for broken filler pipes and cracked gas tank welds. Good luck.