Never ends...

[Vettefan87]

Well today is the last day of nice weather here for a week or so. I figure I will drive the vette to school and go out and run errands today in it, when I start it up I throw the evil SES light. The car ran fine going to school, but I have not had the chance to check the code yet. I wonder what it could be. I will keep everybody informed.

 

[6 Shooter]

Just 1 of the Joys of owning an Older/Classic Corvette

Ya got to love em!

Later . . . . . .
6 Shooter

 

[MBDiagMan]

Don't worry. It's probably not a big deal. Usually a sensor or relay or some such will get that taken care of again.

Good luck and let us know if we can help,

 

[John Robinson]

Codes

Mine throws a code ever once in a while. I have checked and it is for a knock sensor. However after a couple of miles it goes away and the car runs fine. If it were an actual code I would suspect that the car would go into limp home mode. I have tried to see if it occurs more often when it rains or if its cold or if it's boiling hot out and so far can find no common denominator. So I just drive the car and wait for something to actually happen that needs attention. So far I have been waiting for over a year.

 

[Vettefan87]

Well it was code 34. When I started it up at school the SES light was off and stayed off for the duration of when I was in it 2+hours, and the car ran great. I don't know I replaced the power, and burn off relays about two years ago, maybe this spring I will replace them both, if the problem persists.

 

[MBDiagMan]

Check the hose between the MAF and the throttle body. Make sure it is tight and not cracked or otherwise leaking. If you can't find a leak clear the code and run the engine at 2300 RPM or greater for one minute or until the code sets.

If the code sets disconnect the connector from the MAF and repeat the above test. This time code 33 should set. If code 33 sets, make sure that there is 12V at terminal E of the connector that leads to the MAF sensor. If there is indeed 12V there then the MAF is bad.

If the code not set after the test in my first paragraph, then you probably have a flaky electrical connection somewhere, so run it awhile and see if you get the code again.

Good luck,

 

[Vettefan87]

It didn't come back on for 2+hours I was out driving around, a lot of it was at WOT, so I am not too worried about it, that and with the snow coming tomorrow I don't have the time to look at it. Thanks though.

 

[Mad-Mic]

It didn't come back on for 2+hours I was out driving around, a lot of it was at WOT, so I am not too worried about it, that and with the snow coming tomorrow I don't have the time to look at it. Thanks though.

this was the code i was fighting for about a year. mine only came on once a month for about 5 mins at a time. relays go bad and for 7 bucks each easy fix. this could also be your rich/lean problem.

 

[MBDiagMan]

Well, the two burn off relays are indeed in the power circuit for the MAF and could possibly be the problem. Normally I don't recommend throwing parts at a problem without proper diagnosis, but when dealing with an intermittent problem you rarely can do a proper diagnosis.

It's sort of a variation of the "if it ain't broke don't fix it" rule. The variation is "if it ain't broke you can't diagnose it." For this reason and since the relays are relatively cheap, I might replace them unless they had been recently replaced.

When the car came from the factory they had relays that were later superceded with better units. If the car still has the originals then I would definitely replace them with the latest part number from the GM parts counter only. I would not buy these relays aftermarket. I normally will use lots of aftermarket parts, but these are items I would only buy at the Chevy house.

Good luck,

 

[Edmond]

Are you guys firm believers in using only GM relays? Are the aftermarket built ones within good tolerance? I'm not real big on using aftermarket electrical components.

Justin,

It's time to get a C6! :L

 

[MBDiagMan]

As I stated in the previous post I use aftermarket parts for many things but these relays are not one of them. They were upgraded after the originals and I will only use these relays that come from the GM parts counter.

Good luck,

 

[vetteboy86]

Anymore a relay is a relay in my opinion.

 

[MBDiagMan]

It sounds as if you have never had to replace an early or an aftermarket relay. I have replaced both, but I have never replaced an updated GM relay. Tell me, do you reaaly want to take a chance on a $7 part?

Have a great day,

 

[G Winter]

Anymore a relay is a relay in my opinion.

There is a big diff. in many electrical parts. On a relay the guage of the wire they use in the windings, the material and guage in the contacts. This holds true with any electrical-electronic part.As a rule the OEM parts are held to a higher standard.The exceptions are when someone builds a heavier starter or alt. etc and makes a point of it by listing the improvments. My GM parts man gives me a discount on parts and I usually find that there isn't much diff in price over aftermarket parts on most of what I buy. There are some parts such as exhaust that are out of line.

Glenn

 

[Vettefan87]

Anymore a relay is a relay in my opinion.

Lol from the Electrical Engineer himself :L. Nice answer Craig. I will probably buy them this summer, but I thought the relays would last longer then two years...

 

[Edmond]

There is a big diff. in many electrical parts. On a relay the guage of the wire they use in the windings, the material and guage in the contacts. This holds true with any electrical-electronic part.As a rule the OEM parts are held to a higher standard.The exceptions are when someone builds a heavier starter or alt. etc and makes a point of it by listing the improvments.

Glenn,

That was the thinking that I was raised on, that electrical parts are held to a higher standard.

 

[vetteboy86]

Have any of you actually performed any tests on above said relays?????

Oh I dont know, when we were thinking about switching vendors for our automotive relays at work I did some testing on the new relays. I think the brand was sanyo or something like that. Well anyways I cycled it on off for 48 hours straight, 1 sec on, 1 sec off. So figure out the cycles. Sure the contacts started to show signs of arc, but after the initial 48 hours and inspection it was put to test for another 10 hours. Oh I was using a 40 amp dummy load.

I would stay with the OEM relays, AC DELCO if possible, because I am just that type of guy. I think even these parts are being made in china.

 

[MBDiagMan]

Being honest, no I have never done any scientific testing except for paying attention where the failed relays came from. My experience has been that the only relays I have seen fail are the original equipment GM relays, and aftermarket relays. I have never seen one of the updated GM relays fail.

I agree my criteria is not as scientific as a 48 hour, high current, .5 Hz cycle as you did, but as long as I don't have to replace any updated GM relays, I'll stick with them. When they start failing, I will reevaluate.

That time may very well come as these parts start being contracted with Chinese vendors.

Thanks for the test info.

 

[vetteboy86]

Yes I agree, I have only changed those relays once in the cars lifetime. If there was a trend, I would trust that knowledge. Also you cannot always account for that bad part just out of random chance.

 

[Hrtbeat1]

Have any of you actually performed any tests on above said relays?????

Oh I dont know, when we were thinking about switching vendors for our automotive relays at work I did some testing on the new relays. I think the brand was sanyo or something like that. Well anyways I cycled it on off for 48 hours straight, 1 sec on, 1 sec off. So figure out the cycles. Sure the contacts started to show signs of arc, but after the initial 48 hours and inspection it was put to test for another 10 hours. Oh I was using a 40 amp dummy load.

I would stay with the OEM relays, AC DELCO if possible, because I am just that type of guy. I think even these parts are being made in china.

Craig,

I pretty much agree with you ... a relay is a relay. Although I get a better feeling about the Delco parts. Not very technical but the gut feeling. The time will come that these are made in China somewhere and the price should reflect that. I still say if I gotta change it I'm putting a Delco relay back in. $7 is $7.

Actually I carried three spares as my car had 19 relays of questionable sources. Not good documentation with mine when I got it. :L