• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Service Engine Soon Light Is On

Beaverton

SM 2003
Full Member
Joined
Dec 18, 2002
Messages
823
Location
Beaverton, OR
Any one have any experience with this light coming on, and it wasn't after performing an intake or exhaust mod? The only thing I've changed in this area in put in a 2129 K&N filter about 3 weeks ago.
 
Yuo are not filling the gas tank with the engine running are you? AV's have a sealed gas system and are not to be running with the gas cap off.
 
Up here in Oregon, I don't get to fill the tank on my own. To clarify, it came on while I was driving; the gas tank was about half full at the time. I've since had it topped it off and the light is still on.
 
Check and make sure that none of the air intake hoses going from the air filter housing have come loose. That would allow unmatered air to get into the engine and throw a SES Light. Keep us posted.
 
As you noted, the 2129 is for the 5.3L - a post earlier on this thread states that I should be using the 2135 for Z-71, even though I have the 5.3L engine. The K&N site makes reference to a 6.0L engine, which I'm not aware even exists as an option, and makes no reference for a different filter based on the Z-71 designation.
So, before I throw away my box for the 2129 filter and can't exchange it, I want to know if I really should be using the 2135, and where this information is located.



Did you ever figure out the Z-71 non Z-71 option?
 
BeAVertonFAN said:
Any one have any experience with this light coming on, and it wasn't after performing an intake or exhaust mod? ?The only thing I've changed in this area in put in a 2129 K&N filter about 3 weeks ago.

Make sure your gas cap is on tight. This is step one. If your gas cap was not on tight you may have to drive for 75 to 150 miles and the light should go off. If your cap is on tight it's probably time to call the dealer.
 
Thanks. As I mentioned before, we don't pump our gas here, so I don't even think about it any more. I'll make sure the cap is on tight and drive around a bit before I make the call to the dealer.
 
Hey Beaverton,
I noticed that you all couldn't pump your gas when I was up there on a business trip. I asked the attendant (fuel transfer technician) why that was. He said that he didn't know.

So, what IS the reason for that???? Jersey is the same way.
Durwin
 
Durwin said:
Hey Beaverton,
? I noticed that you all couldn't pump your gas when I was up there on a business trip. I asked the attendant (fuel transfer technician) why that was. He said that he didn't know.

So, what IS the reason for that???? Jersey is the same way.
Durwin
It's an Oregon state law. I believe it is to minimize spills from over-filling as an anti air-pollution measure.
 
If your Av came with one free year of On Star, give them a call on the button and they will diagnose the Service Engine Soon light free as part of your package.
 
I had 1,935 miles on mine when my service engine soon light came on.

I took it to the dealer, they ended up replacing the vapor canister and vent solenoid. ?They said they ?were stopped up. ?

The service tech said it could of had some debris from the factory.

500 miles later it seems to be running just fine.

 
Durwin said:
Hey Beaverton,
? I noticed that you all couldn't pump your gas when I was up there on a business trip. I asked the attendant (fuel transfer technician) why that was. He said that he didn't know.

So, what IS the reason for that???? Jersey is the same way.
Durwin

Hopefully, this won't lead to far off topic, but...
I lived here seven years and basically I haven't a clue, nor have I found anyone else who has a satisfactory answer. Some folks attribute the law to environmental concerns, others say it helps create jobs (although the loser my daughter married can't even figure this one out). My introduction to this law was when I was moving here, I stopped to fill up may tank; just as I was putting the nozzle in the car the attendant comes racing out of the store, waving her arms and screaming at me like a lunatic. :2: They take it pretty seriously around here.

Anyway, I made sure the gas cap is screwed on tight. I'll check for air leaks later on tonight. I'm also thinking of disconnecting the battery momentarily to reset the computer.

As for On-Star, I bought mine used, after the original OS subscription expired, and installing my aftermarket radio rendered OS useless anyway (until the adapter comes out). Incidentally, I have just under 50K miles, so the other problems with clogging sound intriguing. I picked up an extended warranty, so we'll see if that covers this problem.
 
The light came on in our '99 Yukon and after 5 trips to the dealer some genius finally figured that there was a leak in the EVAP system.

He found it by introducing smoke into the system then looked for the tell tale smoke!

EVAP = EVAPorative or emissons system.
 
UPDATE.
Just got back from the dealer. Error code was for evap system leak, but testing didn't reveal any leak or other problem. Light is reset and off -- for now.
 
BeAVertonFAN said:
UPDATE.
Just got back from the dealer. ?Error code was for evap system leak, but testing didn't reveal any leak or other problem. ?Light is reset and off -- for now.

Probably a loose gas cap...

SJP
 
From my end of the FWIW department, I had a mechanic tell me at one time that if the Service Engine Light comes on steady, the chances are that it's a minor problem...most likely the gas cap or something like that. However, if the SEL comes on and begins BLINKING.....get you to a dealer ASAP. Whether or not he was pulling my leg remains to be seen, but in the few times it's come on on my wife's Camry, I simply removed the gas cap and put it back on. The light reset itself within a day or so.
 
The situation is this - periodically the ecm on a vehicle with OBD-II (which is what we all have) will do a pressure test of the fuel evaporative system - this is a system which collects and stores fuel vapors and returns them to the fuel tank, if during this test the system fails to hold pressure the CEL (check engine light) will come on. A fuel tank cap not being tightened all the way is possible (but blamed more often than it is actually the problem) , also a leak in a line or fitting, a faulty pressure sensor, purge valve malfunction or bad vapor cannister are all also possibilities. The CEL will come on and stay on anytime a hard failure is recognized.
The light will not go out untill one of two things happens -
1. The code is cleared with the use of a scan toll. (I do not recommend disconnecting the battery to do this as it will clear the ECM memory and learned driving strategy.)
2. If the problem was an intermittent one and does not reoccur for several drive cycles (engine reaching normal operating temp and being driven over 30 mph - shut off and cooled down = 1 drive cycle) the cel will go off and the code will be moved to a history code - still stored but not current. Along with the code a snap-shot ( a list ) of all sensor and control values at the time of the malfunction will be stored as well. The CEL is yellow and not red for a reason - yellow means caution and red means danger - there is no reason to panic if the cel light comes on (thus the yellow color) return it to the dealer or a independent repair shop for analysis or repair when you can.

I hope this clears up some of your concerns and thoughts on the Service Engine Soon light. BTW It will come on solid and not flash unless the ecm has been triggered into diagnostic mode somehow.
 
Back
Top