Service 4x4 message...but no codes?

Hello All, I have a 2000 Silverado 4x4, that gives the "service 4 wheel drive" message about once per week. I've read about the switch issue in prior post, and have noticed that when I get this message sometimes the light goes out on the switch. I can push on the switch housing around the buttons and the light will come back on, or go dim? I'm fairly confident that I need to replace the switch, but when I plug the truck up to a diagnostic scanner is says: MIL is off(at the time the message wasn't displayed), No codes found. There were none in the current of pending codes? Does anyone know why there are no codes stored?

Thanks in advance Sean

2000 Siilverado Z71 Extended cab, sport side 5.3 L

"SMEDDIN" wrote

The code is in history, perhaps your scanner can't read history codes?

Ian

. . . . Service 4x4 message...but no codes? Group: alt.autos.4x4.chevy-trucks Date: Mon, Oct 20, 2003, 8:09pm From: snipped-for-privacy@cox-internet.com (SMEDDIN) Hello All, =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0I have a 2000 Silverado 4x4, that gives the "service 4 wheel drive" message about once per week. I've read about the switch issue in prior post, and have noticed that when I get this message sometimes the light goes out on the switch. I can push on the switch housing around the buttons and the light will come back on, or go dim? =A0 I'm fairly confident that I need to replace the switch, but..............

when I plug the truck up to a diagnostic scanner is says: MIL is off(at the time the message wasn't displayed), No codes found.

There were none in the current pending codes.

Does anyone know why there are no codes stored?

Thanks in advance Sean =3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D Because there's nothing wrong for the sensors to detect?

that's the only reason that codes would'nt be stored......with a good running vehical.

scrib abell ~:~clears the codes ....then scans for codes and wonders why there aren't any~:~

"Scrib Abell" wrote

Not true, the OP said he was getting the Service

4X4 light intermittantly. In this case, the codes will be stored as history codes. So there is something wrong, it's just intermittant.

You can also have "real" problems without having a code set. Take an ABS sensor that drops its signal at lower speeds. There is a problem, but the ABS will never know it, as it cannot distinguish between the signal dropping out, and the wheel locking up.

Whatever you say, Marsh.

Ian

. . . "Scrib Abell" wrote

Because there's nothing wrong for the sensors to detect?

that's the only reason that codes would'nt be stored......with a good running vehical. ====== ====== snipped-for-privacy@hotmail.com (shiden_kai)

Not true, the OP said he was getting the Service 4X4 light intermittantly. In this case, the codes will be stored as history codes. So there is something wrong, it's just intermittant. You can also have "real" problems without having a code set. Take an ABS sensor that drops its signal at lower speeds. There is a problem, but the ABS will never know it, as it cannot distinguish between the signal dropping out, and the wheel locking up.

scrib abell ~:~clears the codes ....then scans for codes and wonders why there aren't any~:~

Whatever you say, Marsh. Ian ======= ======= Ian, yuh know...I read his post....then I read your reply...then I thunked to myself.... what should I do??......me being a self proclaimed scanner dude...

Should I tell him what Ian has already told him?

or...Should I jest answer his question?

so.....I jest answered his question.

which was..."Does anyone know why there are no codes stored?"

a History Code...is a code...and therefore would be A CODE STORED.

he said no codes.....

respectfully marshmonster ~:~hooks the battery cable up and scans for codes....no codes....okee dokee~:~ .

.

.

. wonder if i oughta go through a couple drive cycles and check fer codes again? nah....there gone.....ain't they?

.

"Scrib Abell" wrote

Wouldn't it be smarter to read between the lines of what he is saying? Depending on what scanner he uses and/or his knowledge, he may have either missed the history codes or not been able to access them. But, guaranteed, if he has the t/case light flashing, he will have a code in there somewhere.

That "he could see"....it would be a different story with a Tech II and a knowledgeable user.

Ian

.. . "Scrib Abell" wrote

a History Code...is a code...and therefore would be A CODE STORED. ====== ====== snipped-for-privacy@hotmail.com (shiden_kai)

Wouldn't it be smarter to read between the lines of what he is saying? Depending on what scanner he uses and/or his knowledge, he may have either missed the history codes or not been able to access them. But, guaranteed, if he has the t/case light flashing, he will have a code in there somewhere. he said no codes..... That "he could see"....it would be a different story with a Tech II and a knowledgeable user. Ian ======= =======

If he had just pulled up to the shop with those exact same words, then YES, it would have been smarter to automatically assume that the customer didn't know what he was doing.

BUT...even in that situation.....I would have answered his question the same way.

I then would have proceeded to hook up the ole scannerroonie and pulled a code out with him standing there.

Sorry.....but I jest ain't never got passed the thrill of that look on their faces when you do something with ease.....that they have frustrated over for a time.

any whooo........

the guy is either using a generic AutoZoned $49.95 scanner or doesn't know how to retreive the codes.....in which case he should be asking the apropriate questions.

in case he's still lurking around and paying attention to his own post....here's a site that will answer his questions and confuse him even more.....

OBDII at CSU Address:

good site to explore in....

respectfully , marshmonster ~:~

Hey Marsh, I admit I'm a first time code reader..and it was a loaner Oreily $149 scanner. But in my defense, I did read the instruction manual and followed the instructions to the tee. LOL It did say scan successful, but no codes...even though I keep getting the service 4x4 message. I guess my real question should have been, what do you guys think I should do? Would you reccomend buying a new switch and replacing it myself, or taking it in to the dealer? Thanks for your help Sean

. . My advice would be to call a tranny shop and see if they offer free scans as part of their checkouts, and find out what the computer was saying by an expert that's used to dealing with the system.

most tranny shops offer the service at no charge, just be curtious enough to allow them the repair if you decide not to do it yerself.

MarshMonster tranny tech =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Hey Marsh, =A0=A0=A0=A0I admit I'm a first time code reader..and it was a loaner Oreily $149 scanner. But in my defense, I did read the instruction manual and followed the instructions to the tee. LOL =A0 =A0 It did say scan successful, but no codes...even though I keep getting the service

4x4 message. =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0I guess my real question should have been, what do you guys think I should do? Would you reccomend buying a new switch and replacing it myself, or taking it in to the dealer? Thanks for your help

Sean =3D=3D=3D=3D=3D

most tranny shops offer the service at no charge, just be curtious enough to allow them the repair if you decide not to do it yerself.

MarshMonster tranny tech ================

Hey Marsh, I admit I'm a first time code reader..and it was a loaner Oreily $149 scanner. But in my defense, I did read the instruction manual and followed the instructions to the tee. LOL It did say scan successful, but no codes...even though I keep getting the service

4x4 message. I guess my real question should have been, what do you guys think I should do? Would you reccomend buying a new switch and replacing it myself, or taking it in to the dealer? Thanks for your help

Sean =====