[pont3]

My 2004 Envoy XL SLT equipped with the 5.3 engine, has 113.000 miles, runs great and has been a great vehicle over the four years I've owned it. It has, however announced that I need to "service engine soon". This is different from the more common "check engine light", and I don't know where to start. Are there stored codes for this?

What symptoms could this possibly point to? Thanks.

[70gtojosh]

Service engine soon, check engine light just different terminology for the same thing. You have a code set in the system. My wild guess would be evap vent performance. Fuel cap not on tight or O ring cracked. Vent solenoid not working. If its running ok it may not be a big deal. Good luck.

[daduck]

most of the Big Box (AutoZone/OReillys) Auto stores will plug in their "diagnostic tool" for free in hope of selling you some parts.

[mgarblik]

That particular model could have 1 or more of around 400 possible codes in multiple computer modules. Some are much more popular than others based on brand and year of car. For an Envoy, EVAP codes as mentioned are popular. Also with 113,000 miles, you are due for spark plugs so some P300 series codes are also common. P0170 codes for oxygen sensors are also common with that mileage and converter efficiency codes. Parts store free scan can look at about 50-60 of the most common generic codes. Need a more advanced scan tool to get the rest. Worked on a BMW 530 last week that had 55 codes set in 12 different modules. The Bavarian Money Waster was busy costing his owner a fortune. Your Envoy shouldn't be a big deal.

[TedRamAirII]

Get the code. The Code is like a Compass, and will tell you what direction to go in.
A Code is NOT a Diagnosis.

[Jerry H.]

How long since your last oil change?

[Matt Meaney]

if your car has a "check engine" light and a "service engine soon" then they are not the same thing. there will most likely not be a code set. the service engine soon light will be set up as a reminder of sorts, that the manufacturer wants something done. it may even require the dealer to reset it. check out the owners manual, if you have it, it might send you in the right direction. maybe call a dealer to see what they have to say, just don't let them try to scare you into a big bill.

[400 4spd.]

My wife has been driving an '03 Envoy for about 10 years. The past 3 years it has been nothing but trouble electronically, so this week she starts driving an Expedition. Regarding the evap code mentioned above, new GM gas caps were the fix both times. It seems they are good for a couple of years now.

[Brian Baker]

My '99 GMC Sierra with its 5.3 is getting ready to roll over 304K miles and still runs great. It will occasionally throw a code for lean bank condition (left or right) which is related to the O2 sensors , but I have changed them regularly (every 50K miles or less). Go to Autozone or one of the aforementioned stores and get the code read for free, or buy your own OBD-II code reader and do it yourself. Can't move forward without knowing the code.

[mgarblik]

Originally Posted by Matt Meaney

if your car has a "check engine" light and a "service engine soon" then they are not the same thing. there will most likely not be a code set. the service engine soon light will be set up as a reminder of sorts, that the manufacturer wants something done. it may even require the dealer to reset it. check out the owners manual, if you have it, it might send you in the right direction. maybe call a dealer to see what they have to say, just don't let them try to scare you into a big bill.

The statement above is technically correct, but as often with vehicle repair, it can be more complicated than that. The EPA requires an amber light dedicated to emission related problems and codes, BUT they don't mandate what to call it. It may be a picture of an engine block, may say "check engine", "service engine soon", or "service engine now". It MUST be AMBER and can't just be an English message printed in the Info center. Manufacturers are free to add all kinds of additional lights and messages as they wish. So as Matt says above, if you have a check engine AND a service engine soon light both, the service engine soon is basically a maintenance reminder like it's time to change oil. If it has a service engine soon only light, there is some monitored condition that has an issue. They never seem to be able to make this easy and consistent between brands and years. I would get your free scan and go from there. Probably a minor issue. LS series GM engines are generally very reliable and simple to repair.

[pont3]

Originally Posted by Jerry H.

How long since your last oil change?

It's funny. I usually do my own oil changes but since I needed a state inspection and emissions test to renew the plates, I let Autotire do the change about three weeks ago. And within days that SES light appeared. The truck runs great, like it always has. It idles smoothly and has all the power it ever had. Their are no weird smells at the exhaust and the engine is quiet.

[pont3]

Originally Posted by mgarblik

The statement above is technically correct, but as often with vehicle repair, it can be more complicated than that. The EPA requires an amber light dedicated to emission related problems and codes, BUT they don't mandate what to call it. It may be a picture of an engine block, may say "check engine", "service engine soon", or "service engine now". It MUST be AMBER and can't just be an English message printed in the Info center. Manufacturers are free to add all kinds of additional lights and messages as they wish. So as Matt says above, if you have a check engine AND a service engine soon light both, the service engine soon is basically a maintenance reminder like it's time to change oil. If it has a service engine soon only light, there is some monitored condition that has an issue. They never seem to be able to make this easy and consistent between brands and years. I would get your free scan and go from there. Probably a minor issue. LS series GM engines are generally very reliable and simple to repair.

Thank you for your knowledge. I tried to be specific in stating that it is NOT the "check engine" light, but the "service engine soon" light. I do have a scanner and when the "check engine light" illuminated, I WAS able to pull a code to replace the thermostat, which I did and the "check engine light" hasn't been on since.

I've never had this SES light, and when I plugged in my scanner, it showed zero malfunction codes.

I bought the truck used from the original owner and he gave me all the service records so I will peruse them to see if the spark plugs have ever been changed.

My 2004 GTO just turned 90k miles and still wears its original plugs, too. And it still runs fantastic. I agree, those LS engines with 250k miles on them still run exactly like they did when brand new, and they are extremely reliable.

[pont3]

Every thing I've read tells me the "check engine" light is usually emissions related. "service engine soon" is not directly related to emissions. SO, what mgarblik says makes sense that it is probably some component that is in need of replacement because of duration. I just wish it would tell me what it is that is approaching its expiration date.

I just want to be clear: The truck has NO driveability issues or changes in performance or mpg.

But thanks to all for your responses.

[77 TRASHCAN]

Another BMWism...

Bite
My
Wallet

[Jerry H.]

Originally Posted by pont3

It's funny. I usually do my own oil changes but since I needed a state inspection and emissions test to renew the plates, I let Autotire do the change about three weeks ago. And within days that SES light appeared. The truck runs great, like it always has. It idles smoothly and has all the power it ever had. Their are no weird smells at the exhaust and the engine is quiet.

Could it be they didn't reset the oil change monitor?

[mgarblik]

Originally Posted by Jerry H.

Could it be they didn't reset the oil change monitor?

Yes, you are the winner on this thread I am almost sure now, and I am sorry Pont3 for leading you down the wrong path on this one. With a Check engine light and a service engine light both, yours is essentially an oil change monitor. When you had your oil changed, they didn't re-set it I bet. Get in the car and get ready. Turn the key to the run position. Within 5 seconds, push the gas pedal all the way to the floor and let it go back to idle 3 times. In 5 seconds or so the light will flash 4-6 times and go out. Key off and wait 10 seconds and then start. The light should be out. Sorry about all the unnecessary posts I made.

[pont3]

No, No NO! I do NOT have "Check engine light", ONLY the SES light! I did the reset procedure to turn off the "service engine soon" light and it did indeed go off, but then it came back on.

Seems to me that there is a little bit of reading comprehension going on here. I do NOT have a "check engine" light, ONLY the "SERVICE ENGINE SOON" light. The "reset" after an oil change only requires that you turn on the key, (not start the engine) and press the accelerator pedal three times to reset the oil life monitor. But there seems to be lots of confusion between the "check engine " alert and the "SERVICE ENGINE SOON" alert. They are NOT the same!

The "CHECK ENGINE " light is NOT on, ONLY the "SERVICE ENGINE SOON" is on.

Thanks to Jerry H for his input, but he is not the winner, and mgarblik, he is not on the right path and I believe that you are closer to the problem. I usually do the oil changes on ALL of my vehicles and I know the procedures for resetting the OLMs, but the problem is NOT with the OLM or "check engine" light.

[pont3]

Sorry guys, I don't mean to discount anybody, especially when I'm asking for help. But I don't want to offer any illegitimate advice or have others offer it based on an issue I raised. I get it, most people have long moved on past 2004 cars and not many exist on the roads today. But there are MANY GM 2004 vehicles out there that have lots of life left in them and only need modest investments to keep them going for a longer time.

[poncho-mike]

My car is an 02 Saturn Vue and has a "Service" and a "Service Engine Soon" light.

The Service Engine Soon light has been on steady for almost a year. Some scanners won't read a code, but others will. The light first came on during summer a couple of years ago, but it went away when it got colder. I went to Advance Auto and their scanner said there was no code. I went to a friend who is a mechanic and he gave me a code associated with the evaporative system. I had already replaced the gas cap and he checked some type of small valve and said it was OK. I'm not sure what the problem is, but at 296K I'm not sure if I will spend a lot of money to fix it. I'm not sure if it will keep me from getting inspected.

My Service light came on when an 02 sensor went bad last year.

[mgarblik]

OK. So we have a Service engine soon light and no Check engine light. That means the Service engine soon light IS the Check engine light. You see it's not so much reading comprehension as it is the damn manufacturers being allowed to use any name they want for any light with no clear definitions and different for each manufacturer by year. No fun for people who work on this stuff for a living. So now we have come full circle and are back to getting it scanned. The next issue is there are codes a generic scan tool can read only and codes that a full feature, (manufacturer) scan tool can read. A generic scan tool can read about 60 codes on your car. A full feature scan tool can read about 450 codes on your car. That light will come on for any of the 450 codes. So for free, you can have a parts store look for the one or more of the 60 codes. They are all generally codes for emission related issues. Many of them have ZERO effect on how the vehicle runs. If the light is on and they get NO Codes, then there is only a manufacturer specific codes, (s) stored. They can be specific engine codes, transmission codes, heating and AC, entertainment and comfort, any of the modules. 390 of the total 450. It will take a full feature scan tool to read them and none of them typically will keep the basic vehicle from functioning. Hope this helps.