Service 4x4 MSG??

silverado19 · January 13, 2005

On my 99 NBS Chevy Z71 Silverado 1500 Extra Cab, the service 4X4 msg is comming on in the information center. I went to my local shop and they could not find any trouble codes. My question is, why is the msg coming on? I am planning on servicing the front and rear diff and the xfer case, but will this take care of the msg? Do I somehow need to reset it? Is there a sensor that has gone bad? Any recomendations on the xfer fluid to use?

Any help you can give would be great.

Mark

GMCTech · January 13, 2005

There is a software update that addresses that exact issue - Service 4WD message on and no codes.

Have your GM dealer check it out for you.

Hope this helps.

silverado man · January 13, 2005

More than likely it is going to be your selector switch on the dash going bad it is a common problem. You can by a new one at one of our online vendors or go to www.modulemaster.com and they will fix the one you have for pretty cheap price.

boutbroke · January 14, 2005

I had my doubts even after reading numerous postings on this site but changing the pushbuttons on my 99 Z71 about 3 months ago stopped the 4x4 msg on mine. I had been to the dealer and a local mechanic who gave me different solutions but the guys in the real world on this site steered me straight.

I check GM-Trucks before anyone touches my truck for a repair.

This job was $30 or so for the switch and 3 to 5 minutes to swap it out.

rikhek · January 14, 2005

I'll also bet it's your selector switch. On my 99 my Service 4wd Light came on a couple months ago. Everyone on this forum said it was most likely the selector switch.

I pulled it out and sent it to www.modulemaster.com. They confirmed it had a problem and fixed it for $10.00. They list $15.00 on their site but I called the guy to discuss and he quoted me $10.00. I think I sent a check with it and he didn't even wait for the check to clear. Fantastic guy providing a premium service. He also said his repair makes it better than a "new" replacement as they have a design flaw which he eliminates.

You can drive the vehicle without the switch while it's getting fixed, however, only in 2WD.

Had it back to me 5 days after I put it in the mail which makes like a one day turnaround. GREAT SERVICE!!!

Haven't seen the "Service" light since.

Also, the "Service 4WD" wiil NOT throw an OBDII readable code which is all Auto Zone or most people can read. Been there tried that. It's manufacturers specific code and uses a different reader which dealers and only some shops have. OBDII codes are engine/emissions specific and this is not an engine/emission issue. If I recall correctly any message in the "Message Center" is a manufacturer specific code which requires a different reader. It's a seperate diagnosis system than the OBDII system. The only time an OBDII is used is when the little "check engine" light goes on (i.e., the little picture of an engine) on the dash.

Rick

silverado19 · January 14, 2005

Thanks. Looks like it is off to modulemaster.com for me!! I will let you know what happens.

This will always be my first stop before anyone touches my truck!

Mark

03 GMC · January 14, 2005

Is this common in all NBS or just '99 models? I had the service 4x4 message come on last night on my '03. It didn't come on today.

htneighbors · February 9, 2008

I'd like to know, too - mine came on today on my '03. Although - 2 days ago, while driving on the highway, I looked down and saw the selector switch was lit up saying I was in NEUTRAL! May be a faulty switch like has been the case on this thread!

alaska511 · February 9, 2008

It is the switch. just went through this 2 weeks ago on my 01 tahoe. Buy the switch and do it yourself, cheaper

JJContreras · February 29, 2008

We have a 2005 Yukon XL and the "Service 4x4" Message started coming on about 2 months ago. Do you think it could be a bad switch?

Bish · February 29, 2008

I had the switch go on my 01 Tahoe as well. Dealer replaced under warranty and gave me the broken one. I took it apart and noticed numerous cold solder joints. 10 Minutes with a soldering iron and the switch worked as good as new.

I think a new switch is only about $30-$40 which may not be worth your time but many times it is an easy fix.

Z71Adrenaline · February 29, 2008

My 01 did that intermittently.. I had my 4wd switch replaced and that fixed it. I didn't have the time or resources to do it myself, so the local GMC dealer did it for about $85.. not too bad, but doing it yourself is obviously cheaper.

sleeper42 · September 18, 2008

My 01 did that intermittently.. I had my 4wd switch replaced and that fixed it. I didn't have the time or resources to do it myself, so the local GMC dealer did it for about $85.. not too bad, but doing it yourself is obviously cheaper.

I'm planning a trip this weekend, and I was wondering if the "Service 4wd" light will affect anything?

Majorleaguebass · September 18, 2008

My 01 did that intermittently.. I had my 4wd switch replaced and that fixed it. I didn't have the time or resources to do it myself, so the local GMC dealer did it for about $85.. not too bad, but doing it yourself is obviously cheaper.

I'm planning a trip this weekend, and I was wondering if the "Service 4wd" light will affect anything?

no, it is just a pain in the ass.....haha

PasoRoblesJimmy · September 22, 2008

A dealer said that the intermittent Service 4x4 msg on my 99 Silverado was caused by the encoder motor sensor. It turned out to be a bad diagnosis. A few days ago, the 2Hi light on the ATC Driver Control Switch in my dashboard randomly flickered off and on, then came back on with full brightness. The ATC wouldn't engage/disengage when the switch module lights iwere out, but the ATC would engage/disengage when the lights came back on.

I pulled the ATC switch module GM#15709327 out of the dash, popped off the plastic cover and inspected the solder joints on the circuit card. The solder surrounding the pins of the 2 connectors soldered to the board was cracked in several places. I resoldered the connections, reassembled the cover and reinstalled the module. The repair took about 10 minutes. No more "Service 4x4" messages and no more problems in operating the ATC.

Any person with experience in soldering electronics can do this simple repair in about 10 minutes. I repaired the intermittent windshield wiper motor on my 96 Chevy Sierra pickup by resoldering several cracked solder joints on the circuit card inside of the wiper motor housing.

If you don't know how to solder electronics circuit boards, a replacement Transfer Case Driver Control Switch GM#15709327 can be purchased for a reasonable price from http://www.gmpartsdirect.com.