Dusty_GMT800
Full Access Member
Well, the front driveshaft does get power, so I guess that means it's the front axle actuator. At least I don't need a new transfer case.
4WD not working but no Service 4wd light
- Thread starter Dusty_GMT800
- Start date
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Well, the front driveshaft does get power, so I guess that means it's the front axle actuator. At least I don't need a new transfer case.
rockola1971
Full Access Member
Could be the actuator or the wiring to it all the way back to the 4wd module that supplies the turn on signal to it. Check for 12vdc at the plug to the actuator to see if its there while vehicle is in 4wd mode.
rzabel
Member
I'm going to refresh this thread with my sad, embarrassing story because the title fits, some of the issues are the same....and my truck is weird too! The background is kinda long, but some things may be related....maybe not...you tell me! I have had issues with my 4wd transfer case motor. A year and a half ago, it got stuck in 4lo and I had the motor replaced. 6 months ago I couldn't get it to go into 4wd at all and took it back to the same shop and they said the motor they put in was bad and they replaced it for free. Fast forward to two weeks ago. I have since pulled my trailer down to Mexico for the winter. One day I decided to do a little exploring on the beach. I should have known when the map said 'desolate beach' that I was headed for trouble. On the road there, my entire instrument cluster goes dead. This is the second time this has happened and the first time it fixed itself so I basically forgot about it. I get to the beach and see a place that had some previous tracks that go to a "shortcut" I think. I push the 4hi button and it blinks and then lights up 4hi...no problem (however, I have no instrument cluster to see any other lights). I drive out on the sand and attempt a little hill...normally it would be easy, but this time I bog down. I back down the hill, but get stuck when I get to the flat and soft sand. Uh oh. Before I bury it to no return, I let the air out of the tires, do some digging and putting wood under the tires and try again. Now I put it right down to the axle...but only the rear. A light finally goes on and I realize that I was never in 4wd. Now I'm pushing buttons like a madman. 4 lo and 4 hi do not work (but light up like there is no problem). Then I hear a grinding noise when I try again. Big time UH OH! Finally, I try Auto 4wd and it goes into 4wd and the sand flies up from the front wheels. However, by this time I'm buried too deep to move! A kind and friendly Mexican fisherman saw our plight and went back to the village to get his friend (with a Tahoe) and we were able to pull it out of the hole I had buried it in and drive away with my now working 4wd in Auto. I haven't done anything since and won't until spring when I return north and take it to the previous mechanic. However, I am looking to get an instrument cluster and replace that. So that's my sad story. Any suggestions? Why would it work in Auto but not 4 hi or lo? What was the grinding? Does the instrument cluster have anything to do with it?
rzabel
Member
Okay, now it's spring. I replaced the instrument cluster with a new Escalade cluster and it works fine. I took the truck back to the same shop and they can't recreate the problem. The switch works fine now and it goes into 4wd hi and lo. They say there was no code for any problem with it. Now I don't trust my 4wd switch and don't want to get into a similar problem in the future. Here's a new question. Is it possible to install the old school lever on the floor for the transfer case? Was a manual lever ever an option for these? At work, I'm driving a 2015 Chevy 1/2 ton 4x4 and it has the lever on the floor, simple, easy, dependable. I hate the electronic switch!!
rzabel
Member
I should know by now that no one is going to read or respond to this refresh, but I'm not sure how to get the whole story in a new thread without a bunch of copying and pasting. So...another 6 months has passed, I've used 4wd a couple of times without incident, but today my wife tells me the "service 4wd' message is on the dash. The truck is in Mexico again, so I'll wait until I get home in the spring to have it looked at and read the codes, but now I'm more motivated than ever to see about a retro fit to a manual transfer case.
Has anyone ever gone from the electronic switches to a manual lever transfer case? I searched but can't find anything in the forum about it. Please help!
Once you get the codes read that should help. The three most common problems on these are the dash switches, the encoder motors, and the front diff actuators.
You can ohm out the dash switch to eliminate that, if the code points to that circuit or just as a sanity check. The Tech2 will allow you to test some of the encoder motor functions (like the reference voltage and the encoder return voltages) as well as activate the front diff actuator at will. Best to watch the actuator while it's out of the diff, hanging down. Anything longer than a second or two to fully extend warrants a replacement.
Personally I'm dealing with an issue with mine, where AUTO works fine but in 4hi (and probably 4lo) the front diff doesn't turn the wheels. Still going through some testing but have no codes. It's starting to point toward the TC but we're not quite there yet. I had it "rebuilt" about a year ago and it worked fine for a while after that, but the shop that did it is out of business. If it ends up being that, I'll just get one from transfercaseexpress.com, I guess.
You can ohm out the dash switch to eliminate that, if the code points to that circuit or just as a sanity check. The Tech2 will allow you to test some of the encoder motor functions (like the reference voltage and the encoder return voltages) as well as activate the front diff actuator at will. Best to watch the actuator while it's out of the diff, hanging down. Anything longer than a second or two to fully extend warrants a replacement.
Personally I'm dealing with an issue with mine, where AUTO works fine but in 4hi (and probably 4lo) the front diff doesn't turn the wheels. Still going through some testing but have no codes. It's starting to point toward the TC but we're not quite there yet. I had it "rebuilt" about a year ago and it worked fine for a while after that, but the shop that did it is out of business. If it ends up being that, I'll just get one from transfercaseexpress.com, I guess.
you wont be able to make it a manual switch, well, maybe you could with a lot of time and money like somehow someway swapped a manual hub front differential on it, but its unlikely because the transmission/transfer case are controlled electronically
