What would cause?

[JEFNLSA]

What would cause the SES light to go on for a day or two and then go off for a day or two and so on.....? Right now it is off but it's been cycling like that for the last week it has me wondering. I realize that when it is on, it is throwing a code of some kind (I don't have access to code reader). I hear that Checker etc.. will check/pull codes for free but of course the SES light needs to be on for me to get a code right? The car is running perfect or so it seems....Any educated guesses on this one?? 27k miles on the clock...
Thx,
Jeff
Clutch making more noise than ever (see other thread "chirping"), 6 disc changer threw an error 99 code 2 wks ago (haven't been able to play a cd since?) and now the SES thing. I'm a tad perturbed...

 

[Tuna]

Each time my SES light is coming on, it's been the battery that was going south for winter. I'd check that first, then any electrical connections like battery cables, etc.

Note the voltage before you start the car and after you start it. Then again after it's been on the road for a while. This might give you an indication if the battery is holding enough voltage and power or not.

 

[jester]

The computer will store the code, so the SES light doesn't need to be on to able to read the error code. There are several things that could cause the light to go on and off, so you will need to get the code or codes and work from there.

 

[JEFNLSA]

Each time my SES light is coming on, it's been the battery that was going south for winter. I'd check that first, then any electrical connections like battery cables, etc.

Note the voltage before you start the car and after you start it. Then again after it's been on the road for a while. This might give you an indication if the battery is holding enough voltage and power or not.

Man, I just had the wole electrical system tested (battery,alternator etc..) and it checked out fine in fact, they said the battery was crankin' about 100 more amps than it was supposed to:confused . Regardless, I'll keep an eye on those things. Thx

 

[JEFNLSA]

The computer will store the code, so the SES light doesn't need to be on to able to read the error code. There are several things that could cause the light to go on and off, so you will need to get the code or codes and work from there.

Isn't the SES light supposed to stay on once you've thrown a code and remain on until the problem is solved or at least the code is retrieved? Thx

 

[RonJ]

Isn't the SES light supposed to stay on once you've thrown a code and remain on until the problem is solved or at least the code is retrieved? Thx

If the problem corrects itself, the SES light will go out, but the code is kept in History for a given number of good cycles.

If you can't pull the codes yourself, most good independent shops will put a scanner on for a few bucks and let you know what codes show up. Gees, they will probably do it in the parking lot for you ... <G>

Ron ...

 

[redc4corvette]

I would check just the battery in the A.M. look at your volts and see it they are 14.7 in the am .Your security svstem may be pulling to much power from the battery at night.

 

[JEFNLSA]

I would check just the battery in the A.M. look at your volts and see it they are 14.7 in the am .Your security svstem may be pulling to much power from the battery at night.

Thx to all for the input.....
My ? is...What should the volts be at in the a.m. (14.7 ?) If you can pls give me a general idea of where the volts should read on startup (a.m.) and after she's been driven for awhile. And...if you are correct on the sec sys thing then what can I do to correct the problem. Like I said, the battery tested at 100% and then some so....:confused

UPDATE....I just turned it over after being parked all night and the volts are right at 14.7.....good....bad..? I'm guessin' good but I wanna hear it from someone else :L

 

[Nitronick]

My volts are at 14 or over after letting mine set for a day or two. But it gets back down to 13 pretty quick. There is something drawing down on the battery apparently, though I may have my hood up for an hou or so, the doors open, etc. without starting it. The little cold snap we have had here in Oklahoma may have something to do with it.
I hope this makes sense. I just woke up from a nap

 

[Tuna]

UPDATE....I just turned it over after being parked all night and the volts are right at 14.7.....good....bad..? I'm guessin' good but I wanna hear it from someone else :L

What was the voltage before you started it?

 

[JEFNLSA]

What was the voltage before you started it?

Tuna,
So you're telling me that I can check the volts w/o turning the car over? Never tried that before...I was under the impression that you had to have the car running in order to get a voltage reading. So let me get this straight...I can get a reading before I crank it over (which should be around ?) and then another once I've started it (which should be around ?) This a.m. when I went out for a cruise....it was at 14.7 when I cranked it over and after cruisin' for a bit she dropped to 14.1 and stayed there.

Good?...Bad?...Talk to me.
Thx,
Jeff

 

[RonJ]

Jeff, I get the impression that you are using the gauge in the dash to get your voltage readings. The gauge in your dash is just an indicator, it's readings aren't too reliable or accurate.

Get yourself an inexpensive low impedance digital voltmeter or multi-meter. You can use it to check your battery voltage, TPS voltage etc.

Connect the voltmeter directly to the battery in the morning. Ignition off, hood light should be off and interior lights etc off. A fully charged battery with a specific gravity of 1.280 will give you a voltage of 12.6 without the engine running or any load. If it's 12.4V or less, you have a tired battery for some reason.

With the engine cranking, the voltage shouldn't drop below 9.6V while cranking.

Once running, the voltage will start off above the 12.6V and increase as the battery comes up to charge. The battery voltage should settle out under 15.2V once the battery is up to charge. High 14's above the idle would be normal, depending on the electrical load.

Ron ...

 

[JEFNLSA]

Thanks Ron....good info

UPDATE: Dash gauge reading upon startup this a.m.

12.3 before I cranked it....14.8 after I cranked it....and 14.2 by the time I got to work.

Also, I gotta ask this...Lately I've just been leaving the keys in the ignition when I park at home or at work as opposed to taking them out which would activate the security system. My guess is that, if anything, it would draw no power (which would be a positive...no pun intended ) to leave the keys in the ignition as long as the key is in the OFF position. Am I right? Maybe I should just disable the Sec Sys if it is drawing power cuz I really don't use it anyway.

Any opinions on this and the keys in the ignition thing?

Like I said...I had the entire charging system checked out less than a month ago and everything checked out AOK.:confused

FYI...The reason that I had it checked is cuz I left the interior lights on all night and it killed the battery. The next day I took it to to the shop to see if I needed a new battery and after checking the system they said all was good and that the battery had recharged itself and was actually at over 100%.

Thx all,
Jeff

 

[tlong]

ABCs of the Vette lingo

I believe SYS not SES indicates voltage fluctuations, SES is operational code indicator. Throw a OBDII on it. Emission system.

 

[JEFNLSA]

I believe SYS not SES indicates voltage fluctuations, SES is operational code indicator. Throw a OBDII on it. Emission system.

It's definitely SES....I'm not familiar w/ the other one. What does SYS stand for?

I know... I know...I have a Vette repair manual coming for Xmas!!

 

[tlong]

The SYS monitors the electrical SYStem, and fires when there's voltage parameter violation. SES means Service Emission System. The code is then read by the OBDII scanner. The code should be component failure specific.

If you pay to have your oil changed at Express or something they can read the history free, as can auto parts places. Sounds like the system is working as designed.You have to take it from here!

Happy Holidays

tlong

 

[JEFNLSA]

The SYS monitors the electrical SYStem, and fires when there's voltage parameter violation. SES means Service Emission System. The code is then read by the OBDII scanner. The code should be component failure specific.

If you pay to have your oil changed at Express or something they can read the history free, as can auto parts places. Sounds like the system is working as designed.You have to take it from here!

Happy Holidays

tlong

tlong...would an emissions prob cause the SES light to go on for a couple days and then off again. I figure if something took a @#$!, it's not going to repair itself.:confused

PS Happy Holidays to you & yours as well.

 

[1995 RedVette]

Thanks Ron....good info



Also, I gotta ask this...Lately I've just been leaving the keys in the ignition when I park at home or at work as opposed to taking them out which would activate the security system. My guess is that, if anything, it would draw no power (which would be a positive...no pun intended ) to leave the keys in the ignition as long as the key is in the OFF position. Am I right? Maybe I should just disable the Sec Sys if it is drawing power cuz I really don't use it anyway.

Any opinions on this and the keys in the ignition thing?

I'm not sure if this is normal, however, my 95 will try to lock the doors about every min or so with the keys in the switch and the PKE on. The lockes will twitch like the PKE is trying to lock the doors, then will reverse back to unlock position. I left the car in the garage for about 2 weeks back when all of the tropical storms were coming through earlier this year with the keys in the switch and the battery was too weak to crank the car.

I don't know if the twitching locks is a result of the PKE fob going into sleep mode, or if it just perhaps the PKE going bad. Anyway, I don't leave the keys in the car unless the PKE is disabled anymore and I haven't had any problem since.

Brett

 

[tlong]

I'm not Gordon Killebrew the Evil Genius that invented this stuff but think it goes into a history folder and doesn't stay on all the time. Just a loose connection or clogged EGR could come and go. The answer lies within the little black connector pointing at your privates.

 

[SSTibet]

Jeff,

You can turn the ignition switch to ON (immediately before engine cranking) and read battery voltage from the digital gages. This is how many volts your battery has. You can then start the engine and read the same voltage; this is how many volts your alternator is producing for your battery. Two readings, as far as I understand, are two altogether different things. If you have lower than 12V at ON position your battery is dead meat.

I had my SES light on and off like yours when I first got the car. It ended up being the O2 sensors. Never saw that SES after replacing all 3 x O2 sensors