Service 4wd & 4wd Switch Lights Out

[skellatores]

Turned the truck on today, 2003 Sierra 2500hd diesel and not only is my 4wd switch not lighting up but the service 4wd message is on the cluster. This is a really bad time too cause we just got a bad snow storm. I asked a few friends around and they said it could either be the switch itself or the sensor on the transfer case. They also said that i have to go to the dealer in order to get a scan so ill have to wait till monday and drain my bank account too. What do you guys think it could be? Ive checked all the fuses i think might be linked to the 4wd and they all seem fine. Any ideas, I scanned through the forums and couldnt really find anyone that has had all their lights go out like mine.

 

Any advice would be appreciated,

 

Thanks.

Kyle.

[alwcurlz]

Turned the truck on today, 2003 Sierra 2500hd diesel and not only is my 4wd switch not lighting up but the service 4wd message is on the cluster. This is a really bad time too cause we just got a bad snow storm. I asked a few friends around and they said it could either be the switch itself or the sensor on the transfer case. They also said that i have to go to the dealer in order to get a scan so ill have to wait till monday and drain my bank account too. What do you guys think it could be? Ive checked all the fuses i think might be linked to the 4wd and they all seem fine. Any ideas, I scanned through the forums and couldnt really find anyone that has had all their lights go out like mine.

 

Any advice would be appreciated,

 

Thanks.

Kyle.

 

 

I had that problem too. Found on the net it was a solder connection problem on the 4WD push button panel. Was a pretty easy fix. Just removed the dash bezel, control panel. Took the 4x4 control panel apart and re-flowed the solder on the connector pins where the wire harness connects to. The problem stems from an issue where the wire harness is hanging on the connector pins that are soldered to the board, eventually working them loose.

Hope this helps!

[skellatores]

Thank you for the advice. im gonna go pull the switch out of the dash right now and check it.

Thanks again.

[skellatores]

so i took out the switch unit and opened it up. the soldering you did was on the pins (mounds on the board)?

they look fine, but if that's what you re-soldered then i'll give it a shot.

[alwcurlz]

so i took out the switch unit and opened it up. the soldering you did was on the pins (mounds on the board)?

they look fine, but if that's what you re-soldered then i'll give it a shot.

 

Yes, the pins in the board can come loose and not look obvious, similar to a cold solder joint. It won't hurt to reflow the solder. Let us know the results!

[skellatores]

Okay, so i re-soldered the pins on the board and it didn't seem to work. I plugged it back in and turned on the truck and no lights came on and there were no options for 2wd or 4wd. I'm gonna try this thread http://truckmodcentral.com/forums/showthread.php?t=2290 first and then ill resort to the dealership.

The price of these parts will be the same price to put the truck on a computer so ill try this first and then go from there.

Thanks for all your advice.

Ill let you guys know what ended up happening.

 

Thanks to BigRedMariner for the other thread.

 

Kyle.

[skellatores]

So I had the transmission scanned for $105 and they told me it's the worst one, The Transfer Case Control Module. It's gonna run me around $900 for the part and a hour of labor to install. I was hoping it was either the switch or the sensor but no luck.

[Paxonator]

So I had the transmission scanned for $105 and they told me it's the worst one, The Transfer Case Control Module. It's gonna run me around $900 for the part and a hour of labor to install. I was hoping it was either the switch or the sensor but no luck.

 

I had the exact same problem as you last week. I had no lights and it said service 4wd. I searched on here and found the atc fuse had blown. replaced that and it's worked fine every since. Not sure why the fuse went out though...

[alwcurlz]

So I had the transmission scanned for $105 and they told me it's the worst one, The Transfer Case Control Module. It's gonna run me around $900 for the part and a hour of labor to install. I was hoping it was either the switch or the sensor but no luck.

 

I had the exact same problem as you last week. I had no lights and it said service 4wd. I searched on here and found the atc fuse had blown. replaced that and it's worked fine every since. Not sure why the fuse went out though...

 

 

Hope it doesn't cost joooo $900+ for a fuse.

[Paxonator]

Hope it doesn't cost joooo $900+ for a fuse.

 

Sure hope not, although it did get really cold just before it happened. Like for example today it's -42C here

[alwcurlz]

Hope it doesn't cost joooo $900+ for a fuse.

 

Sure hope not, although it did get really cold just before it happened. Like for example today it's -42C here

 

 

I think that if components get seriously cold, they won't want to move being too stiff and stuck. A motor trying to operate a stuck component would either blow a fuse or burn out the motor.

[hitempguy]

If your'e in Edmonton, (something about the -45C) send this guy a email, he is awesome. [email protected]

He diagnosed my 04' sierra 1500 crew,over the phone. I had exact same problems and the tcase was toast and the encoder motor was failing/failed causing the tcase apply clutch to fail, then the apply clutch bearings ended up in the bottom of the case which led to a shifter fork breaking. 800.00 for my NP246 with a "real" oil pump case saver and Morse Hy Vo chain, new clutches and bearings....

 

encoder motor was failing/failed - thats why my fuse went, could be a encoder motor sensor short. you could just replace the sensor, but the little gears inside rotate back and forth constantly, so IMO while your there, under the truck eating dirt, put a new one in. Craig can get a new aftermarket for 250.00

Everything works excellent now

[alwcurlz]

If your'e in Edmonton, (something about the -45C) send this guy a email, he is awesome. [email protected]

He diagnosed my 04' sierra 1500 crew,over the phone. I had exact same problems and the tcase was toast and the encoder motor was failing/failed causing the tcase apply clutch to fail, then the apply clutch bearings ended up in the bottom of the case which led to a shifter fork breaking. 800.00 for my NP246 with a "real" oil pump case saver and Morse Hy Vo chain, new clutches and bearings....

 

encoder motor was failing/failed - thats why my fuse went, could be a encoder motor sensor short. you could just replace the sensor, but the little gears inside rotate back and forth constantly, so IMO while your there, under the truck eating dirt, put a new one in. Craig can get a new aftermarket for 250.00

Everything works excellent now

 

What do you mean by "real oil pump case saver and Morse HyVo chain"?

[philzinn]

I just got back from the dealer, $700 poorer for a new TCCM. Was having the same problems with service 4WD light coming on. Was a CO324 code. Had problem also that the truck would draw all power out of the battery in 2 days. It was excessive draw by the TCCM.

[1999Yukon]

I just got back from the dealer, $700 poorer for a new TCCM. Was having the same problems with service 4WD light coming on. Was a CO324 code. Had problem also that the truck would draw all power out of the battery in 2 days. It was excessive draw by the TCCM.

I know this is an older thread but same thing is happening to my Yukon right now. Got home tonight and the truck stalled. Tried to start it and it was like the life was sucked out of the battery. All kinds of clicking noise coming from under the dash. Service 4wd light has been coming on for a while, time to do something about it now. Luckily I can get a used TCCM from a wrecker for $125, about the same price as the dealership charges for the test. Have already checked the 4wd switch and replaced the encoder motor.

Hope this helps someone else down the road.