Service 4wd diagnosis

Some tips and tricks and what I have learned troubleshooting the extremely faulty four wheel drive system in Chevy Siverado and GMC Sierras. I do this all without a scan tool, and a cheap fix tip that could save you hundreds of dollars.
How to change the transfer case shift encoder motor here:
kzbin.info?o=U&vide...

[@ryandimaquibo8240]

I can’t believe how well you went through the process. So much better then other. I changed everything before looking at the 4wd ground wire. Cleaned it then worked great

[@GSEShop]

Ryan Dimaquibo so did I, that is what inspired the video. I even took it to a professional shop and they couldn’t figure it out. They changed the front axle actuator twice and told me they kept getting bad ones. I took it home and troubleshot the wiring and this is what I found.

[@MrBktart]

I followed every step of your video and finally SOLVED my issue! I had to add my own wire as I had a break somewhere in the ground line just like you did. Thanks for making this video! Wish every video explained the situation and how to resolve it like you have here!

[@GSEShop]

Thank you for the comment. I am glad I helped

[@tonygick9833]

DUDE I OWE YOU A BEER!!!! I did the same thing and the guy I bought the truck from even changed the transfer case trying to fix it. I replaced everything else and was about to rip the harness out when I seen your post. 5min after locating that 4 pin connector added a ground and BAM!! it's fixed thank you soooo much!

[@GSEShop]

Tony Gick Miller lite please, and your welcome

[@billdieck7393]

Thanks for taking time out of your day to share your experience! I'll use your techniques to check my Suburban. One thing I'd like to suggest is when reconnecting the wire connectors, add dielectric grease on them. Some of my issues in the past were related to moisture in the connectors under the truck. Thanks again!

[@GSEShop]

Not bad advice, but thanks for the praise. If I ever redo this video I will add it

[@HazeeeFishing]

Dude I just replaced the actuator and spent forever trying to clean up the old ground and everything just to watch this and tap into the ground wire at the harness and run it to the main engine ground spot under the hood, thanks a ton! Fixed my problem instantly I cant believe I didn't think of this sooner glad i had all the supplies being it 10:30pm😁

[@GSEShop]

Ryan Hazelton glad to hear it

[@CptRadical]

This is the best video. Thank you for taking to time to make it. I hate spending money on service that I can do myself. Thank you. Great video.

[@GSEShop]

CptRadical thank you

[@erickaloko]

Dude this insanely awesome fix worked for me. Big ass snow storm hitting us in MN tomorrow and you just saved my ass. I sincerely appreciate you sir. Thank you so much!

[@GSEShop]

Thanks for the comment. Please like and subscribe

[@bjsapilot]

I watched this video before doing anything. You were absolutely 💯% right.. Got my meter out. Checked all 4 points. Found no ground. I ran a temporary ground wire and tested. Sure enough it worked. So, I ran a new ground wire. No more "Service4wd" ... Awesome. Thank you for your post on this.

[@GSEShop]

Your welcome: I just don’t want others to struggle and spend money like I did. Please like and subscribe

[@hpslozkyolivas683]

Thanks for taking time out of your day to share your experience! Especially how easy it looks with your explanation

[@GSEShop]

Your welcome, I hope it helps

[@miguelvalenzuela]

God bless you brother, thanks for your patience and generosity by making this video and helping so many of us. Cheers!

[@GSEShop]

Thank you for your comment and your welcome

[@troybonar9674]

Excellent video. Very thorough. Thank you for going through each potential item and also what didn’t work...... it was interesting how things looked back and you tied in different steps, also enjoy the additional detail for people that don’t use the tools often.

[@GSEShop]

Troy Bonar thanks I try my best. Please give a thumbs up and a subscribe

[@danwoyak3681]

I had this problem along with the loss of cruise control. Turned out to be the ignition switch. A local tech figured it out for me after I had gone through all of the grounds and fuses etc. Didn't take him long. If you don't have the tools and or diagnostic skills sometimes it pays to take it to someone that does. $100 fix for me. Great video. Pretty cool watching you guys drill down on stuff like this.

[@GSEShop]

Thank you, I like the challenge

[@ScottysDetailing]

Great video on how to fix the 4x4 system and clean and simple plan too. Love where you should the 4x4 grounds are.

[@GSEShop]

ScottysDetailing thank you

[@ramirogutierrez2940]

If it says service 4wd is the 4x4 messed up

[@yotuact8936]

Brother that was a great video. I'm educated in electronics and love auto electronic troubleshooting. Your video will help many people find the failure related to the notorious service 4WD message with your troubleshooting procedures. There is nothing wrong with repair shortcuts like your repair if resources are limited or just need to get up and running quickly. Most will start throwing money and parts at their trucks so thank you for taking the time to share. I've subscribed and will keep an eye open for more videos from you. Take Care. Stephen from North Carolina

[@GSEShop]

Yotu Act thanks, I love to troubleshoot as well.

[@jdmaxxin3812]

Thank you for sharing this. It definitely saved me money and time swapping parts and the headache of chasing it around. Wired it up the same way and the 4wd was back to working order.

[@GSEShop]

Your welcome

[@garyjordan3181]

Good info 90 percent of the electrical problems can be traced back to lack of ground. Thank you for sharing. Make up a simple jump wire @ 3' long with a clip on both ends to do your ground testing is one of the cheapest and most useful tools you can have. Very good info. Thanks

[@GSEShop]

Gary Jordan good idea

[@a10moondog1]

Tough filming with one hand; camera work was a bit rugged but the information was priceless! Thanks for posting.

[@GSEShop]

a10moondog1 yeah I am a mechanic first, a carpenter second, a mason and electrician third and somewhere near the bottom is cameraman. Thank you for watching

[@DocOnTheRun]

Phenomenal video! You should be teaching this stuff at a college. Could not have been more thorough. Really impressive skills in explaining the process and reasoning behind it. Thank you!

[@GSEShop]

Your welcome

[@jacobygantz2733]

Man you are so awesome, I was at such a loss, switched out the selector ordered the actuator (which is now cancelled) and just happened to stumble on your video and as soon as I watched it I knew this is exactly what it was, went to Home Depot bought a multimeter, a pack of vampire connector and sure enough after maybe 30 minutes in the garage, my selector lights are working, service 4wd message is gone, and this encoder sounds like it has so much more power! Thank you so much you helped me out a great deal and I’m sure you’ve saved many asses, hats off if your ever in Oklahoma, beers on me!!

[@GSEShop]

Thanks, not sure about the more power, but hey if I am ever near OK I will let you know

[@codesempireunleashed7899]

Thanks for sharing this! It gives me a great starting point to figure out my 4x4 issue on my Tahoe. 👍

[@GSEShop]

CodesEmpire UnLeashed no problem

[@michaelenfinger8299]

@@GSEShop b he no

[@GSEShop]

Michael Enfinger ok

[@BBB-ly8ro]

Blue wire? Three phase? Haha. Great video bud. Thank you for sharing the knowledge.

[@GSEShop]

BB B thanks for the comment

[@RodJ]

Thank you, mine started doing this yesterday. I'll try to fix it myself.

[@GSEShop]

Rodney good luck

[@rexjonez2918]

Did it work

[@RodJ]

It was the ground on the frame underneath the driver side. Hasn’t done it again.

[@careybuchanan400]

Dude, you rock! I had the same issue on my 2005 SLE, with a Code C0379. I didn't have a power probe (ordered and coming in tomorrow) so I back probed the ground wire at the actuator connector with a paper clip, attached a jumper wire to that with a small needle nose vice grip, and attached the other end of the wire to a random frame bolt with another pair of vice grips. Powered up, hit the 4H button, BAMM! it worked. Hit 2wd and it switched back no problem. I followed the harness from the actuator up under the hood, where it connected to the same style plug as you showed. Spliced into the black wire and ran the wire over to the right side of the brake booster to a firewall stud located between it and the fender. I liked that the wire was a little more discrete in that location. Thanks for taking the time to do the video.

[@GSEShop]

Carey Buchanan I am glad, I just hope I can save someone else the sleepless nights and money I spent. Please like and subscribe

[@GSEShop]

By the way the power probe is worth every penny

[@user-xv6ge5dv1e]

My kind and of guy right there! I’ve been having problems with mine and when it works it works. I know I’m having the same issue. I’m just going to jump to the fix. Reasons why I watch KZbin before I even take anything apart. Why waste time when someone already has! Thanks for the help!

[@GSEShop]

Awesome thanks for the comment

[@greateaglediaz6963]

Thanks for the advice! I'm sure helps a lot of people

[@GSEShop]

Salomon Diaz I hope so

[@griffinbennett9256]

Great video and info!! And I appreciated the comment at the end about losing your favorite wrench, gave me a chuckle. Subscribed!

[@GSEShop]

Griffin Bennett thanks, I am glad you liked it.

[@mcciaccio]

Thanks, I have a low milage 07 duramax that the 4whl drive hasn’t worked in 5 months. It’s horrible in 2wd in the snow and mud. I worked at a shop in my early 20s but its been decades. I was getting super frustrated with it and myself. Your video helped me a lot as far as what to look for and how the system works. All my other trucks were manual trans and manual 4x4 so were easy. With your video and 1/2 of a Sunday I was able to get it working again!👍😀

[@GSEShop]

Great thanks for commenting

[@alexbellotti3087]

Same as many others who have seen your video, thanks man. I swapped out the encoder motor and switch. Nothing worked untill I checked the grounds and added a ground wire.

[@GSEShop]

Glad I could help

[@oillease1881]

Trying to get my 93 body changed and all this is done with a lever.

[@mzootie9]

Hi I have been troubleshooting for some time on my 4WD issues. So I went through the progression of the grounds cleaning first. Then instead of replacing the actuator motor i decided to go after the position sensor within, much cheaper of course. I got the AC Delco on Amazon for $35. So when i disassembled the actuator i noticed that the gears were previously matched marked but low and behold the factory match mark did not line up. I went and installed the gear, not where i found it but to the factory marks. So yes the smoking gun! I reassembled everything and my intermittent service 4WD and the selector switch with the random lights coming and going were gone! That's great unfortunately it still would not shift into 4WD. So next step was the front diff actuator. I pulled it out and gave it power but it didn't budge. So I checked the voltage at the plug and got the 12 volts on the brown wire but got no ground on the black wire - should have read 000 on the ohm meter but only read 1 meaning no ground like the video. I tapped into the ground with a vampire connector right close to the plug instead of chasing it back. I ground down a spot on the frame and ran new wire to the frame and fastened it with a self tapping screw. Tried it again and Viola! the motor turns. Reassembled it all and it works perfect. Thanks so much for the video help and helping the diagnosis, solved both issues for $35.

[@GSEShop]

Your welcome, please like and sub. Hearing this makes it all worth while

[@halfassranch8363]

Right on, good info.

[@GSEShop]

@@halfassranch8363 thanks

[@halfassranch8363]

@@GSEShop your video has by far been the best. It covers all the other videos I've watched in one. I'm pretty sure its the dash switch but all my freaking tools are in storage and two hours away.

[@GSEShop]

@@halfassranch8363 your welcome

[@bc8265]

Thanks for posting this, my Silverado is doing all of the wonky selector switch stuff as well. About to jump in now.

[@GSEShop]

Cool how did you make out?

[@JerichoRally]

Fantastic! I'm going to try this on my 2006 c4500 dump truck. I can hear it working but now I know what else to look for. Thank you so much!!

[@GSEShop]

Your welcome

[@sirenamireles830]

thanks for sharing! I'll try running ground wire tmrw. Was wondering if its not to much to ask The blue wire you ran. To which color wire on the clip did you tap into?

[@GSEShop]

Sirena Mireles if I remember correctly it was black, but please check the diagram for your vehicle

[@sirenamireles830]

@@GSEShop thank you and will do thanks for reply.

[@brianweber6112]

Thank you. Great info. We have to turn in to detectives with our vehicles.

[@GSEShop]

being a mechanic takes more than just the ability to change parts, most of it is figuring out what part to change

[@bichitoarroyor8726]

Tnx friend, i just got a Avalanche with this problem, i was looking for info on how to fix it, keep t vids coming i just subscribed!

[@GSEShop]

Odi Arroyo thank you twice

[@jordansmith4289]

Thanks for the tips, like you said a thousand dollars later and still no 4x4, it's drove me crazy until now!

[@GSEShop]

Jordan Smith your welcome

[@nilsondavis39]

Thanks man! You rock! 🤘

[@GSEShop]

Master Davis welcome

[@ramirogutierrez2940]

Mine says service 4wd is the did the 4x4 mess up?

[@tyte90]

Gonna have to try this. I tried the motor, the switch, the brain, the ground on frame, front actuator and transfer case speed sensor and nothing has worked. Thank you for posting this.

[@GSEShop]

nick newman I even took it to a pro shop and they couldn’t figure it out

[@mahatmasloth6543]

THANK YOU SIR! i'm about $400 in on this fix so far. So glad I found this video, gonna try these suggestions tomorrow. was about to go get the TC motor but maybe this will save me a few hundred... fingers crossed

[@GSEShop]

Fingers crossed, I hope it works

[@cjrciadt]

Thank you for your excellent video! My Yukon XL dropped into 4L from 2H by itself on a highway today lol! Checked every ground on the frame, wires and the 4wd fuses. Wallet and Yukon not ripped apart!👍

[@GSEShop]

Glad I could help

[@GSEShop]

Thanks please thumb up and subscribe!!

[@GSEShop]

Thanks

[@antncase1]

Great video. I've been fighting this for months now.

[@GSEShop]

Anthony wright thanks

[@ackrite11]

Awesome video brotha!! Glad I found this video I was about to start changing out unnecessary parts. I followed your instructions but I ran my ground wire underneath the driverside next to the main grounds. Got a clean ground and now my 4x4 is working again!

[@GSEShop]

Great, like I said in the video “a ground is a ground is a ground”

[@ackrite11]

Your saving people a ton of money! Good for you!

[@ronmiller682]

Thank for sharing this video. You explained everything so people can understand it. I just replaced my switch, it didnt work then after driving down the road I tried again and it worked, got home moved a little snow and it quit working again. I thought well I'm gonna check the harness tomorrow. But thank for pointing this out. It helps people out so much. Thank you again. Ron

[@GSEShop]

Welcome

[@djpapachris]

I have a 2004 Avalanche ...Service 4WD ...same issue.... I am going to try this, I too have been fighting for 2 years... replaced switch, replaced TCCM..... error comes on ocasionally (usually when you need it.) has been working great for months until the Giant pot holes on the interstate jarred the truck to death.... no more 4WD....... I am more than sure it is a Ground wire, you have given me a great place to start...THnx

[@GSEShop]

You’re welcome

[@fernandoalvarez6727]

Actually a very helpful video! Going to try this on my '01 z71 4.8. Got one for you. I lost all drive while shifting through 2 and 4wd. Now when I shift from neutral to park I get a grinding sound. Park doesn't lock the wheels. Someone who knows, will know in a second. Please help me out. I hate to throw parts. Reason I really love this video. You actually show how to diagnose. Thanks man!

[@GSEShop]

Check out my Silverado pops in neutral video and my one one replacing the transfer case shift motor. I think your answers are there

[@colegunnar1271]

Money saver thanks a lot. Much appreciation for this video man. Didn’t spend a penny thanks to you.

[@GSEShop]

Your welcome

[@joseespinoza-on8ve]

i have that problem with a customer sierra. thanks for the tip, hello from Mission Texas

[@GSEShop]

jose espinoza no problem I got another video on changing the motor

[@Dentiddo]

Thank you for the video. I have the same message popping up on my 05 GMC Yukon. I think this video will help me better diagnose what's going on with it. Again, thank you.

[@GSEShop]

Glad I can help

[@triplebbb2862]

Seriously, thank you very much. I’ve been changing all kinds of things and running through all kinds of things.

[@GSEShop]

You are welcome sir, glad if I helped

[@DstromL]

So after i took a look at the cables at the shaft and sqeezed them for a bit it worked.. so thank you for saving me alot of money

[@GSEShop]

Linus Dahlström I recommend putting a zip tie on pulling the connectors together then

[@paulmessina1301]

After watching a couple vidoes and in one it said the form said to start with cleaning off ground bolts. All I did was clean the ground bolts with wd40 and toothbrush and it worked . Before that none of the lights for 2wd 4wd lights were alumanating and was getting service 4wd code. All good now. Thank god for youtube 🙏

[@GSEShop]

The wires will corrode and that way my problem so I spliced in the other ground wire. Glad the simper fix worked for you

[@last1king]

Man I can't thank you enough for sharing this knowledge. God bless you

[@GSEShop]

Thanks I try

[@NeilFehr]

Thanks for actually explaining what to check for, cause I was about to try replacing everything as well!

[@GSEShop]

That is what I try to avoid

[@joshblade9317]

Dude you just got a new subscriber to your channel Thank You for an Amazing video I had checked all my fuses and cleaned the grounds and nothing spent awhile searching online found your video and with in 15 min had it fixed

[@GSEShop]

Thanks, just trying to help

[@JohnMPavin]

The best video for 4x4 problems.

[@GSEShop]

John M. Pavin for GM maybe, thank you.

[@shadad7774]

Appreciate the video walk through, my 04 z71 just threw the service 4x4, I am going to change out the selector switch anyway as the buttons are pretty beat up/scratched up but will do the steps you showed while I'm changing it out just to be safe as well

[@GSEShop]

You are welcome and good luck

[@andystallings9407]

Thanks so much for this video, I’m just now having problems and I believe you may have saved me a ton of money! I really appreciate you!

[@GSEShop]

Your welcome

[@GSEShop]

@BEATING NCP93 mine or his?

[@tylerpearce2891]

Great video and you made it very dummy prof I dread electric stuff but after watching this I feel pretty confident I can figure this out

[@GSEShop]

Thank you, that means a lot, please like and sub

[@richardnottelmann58]

Thank you for the in-depth troubleshooting. This will save me a lot of time and effort for my service 4 wheel drive on my 06 Sierra

[@GSEShop]

Richard Nottelmann I hope it does, thank you

[@carlwilson8045]

Great video, one handed dexterity is looking good, I did an o2 recently and had to connecti it one handed, it took a bit but i got it. No to try and fix this ground issue, I have already cleaned the terms under the truck on the frame, so not i will check the front acuater ground. thank you very very much for the video, good good stuff here.

[@GSEShop]

Thank you

[@jakedehahn5475]

Awesome how you explained everything so it would make sense really good video

[@GSEShop]

Thanks, I am glad you liked it. Please like and subscribe

[@573customs6]

Good video. My has been acting up and quit this morning. Ill try these tips. Thanks.

[@GSEShop]

I try

[@cuauhtemocbarragan9632]

Let's make this guy have a lot of views for this bad ass video so he can get some money for all those parts,thanks for the video man...

[@GSEShop]

Cuauhtemoc Barragan thanks man

[@edtaber5326]

Thanks for a realistic explanation and video man. It wasn't my problem but it did eliminate everything to the point I did figure it out. Thanks again

[@GSEShop]

What was it for you

[@hanjoni]

Great video.Thanks for taking the time. Headed out to check mine and fix the service 4wd.

[@GSEShop]

Good luck

[@hanjoni]

@@GSEShop Upon turning ignition on (2005 Yukon XL 2500)transfer case switch lights would cycle through all settings then i would have no light at all. Service 4wd would then appear. Before watching your vid I took out switch, checked it with voltmeter and got funky readings. I replaced switch but it didn't correct problem. Checked and cleaned grounds under door. Checked connection at Actuator as in your vid and found other than they were spattered with grease all readings were as in your vid. All good there but problem persisted. Checked wires from motor on Transfer and they looked intact. Still scratching head at this point. Now thinking it had to be the TCCM I unplugged it and 4WD and TREC fuses at same time for about 5 min. When I connected everything back, the problem was fixed. Looks like it was just gremlins. Did read somewhere about the TCCM going to sleep and must be woken up by pulling fuse. I dunno. Happy not spending $$ on new module. Thanks again for your great vid and I hope this helps someone.

[@GSEShop]

@@hanjoni thanks, I have never had a tccm go bad. Never heard of one going to sleep either. Thanks for the input

[@omallyman]

sounds like you watched the same videos I did and started chasing parts $$$ thanks for posting ! I sub - d

[@GSEShop]

omallyman thank you I hope it helps a bit

[@randyderochie2731]

I did the same exact thing and replaced EVERYTHING! I hope adding a new ground will fix it. I've been at it for 3 straight days. 😤😡 (I got yelled at too 😂) Anyway, thank you for taking the time to share!

[@GSEShop]

I hope this helps

[@philwolf6757]

Any luck?

[@randyderochie2731]

@@philwolf6757 unfortunately I've been injured and cannot try it.

[@blahbadyblah7928]

The grounds on this body style are so problematic that there should have been a recall. Thank you for the heads up on this one!

[@GSEShop]

Blahbady Blah no problem, and there is so much rust everyone will have a problem eventually

[@L1ghtstorm]

On my third switch in a 2005. Thanks for extra troubleshooting though in future

[@GSEShop]

Sj Young welcome

[@halfassranch8363]

Mines a 05 and I'm about ready to set it on fire.

[@tomascharles5080]

Good job helping people out.

[@GSEShop]

Tomas Charles thank you

[@wbcmt847]

Thank you for the video! I will let you know how it turns out.

[@GSEShop]

William BCMT welcome

[@trampleonserpentsandscorpi8576]

How did it turn out?

[@mrkeopele]

Winner , Winner, Chicken Dinner!! Nice amount of information, just what I needed to see before I start t-shooting mine! thanks so much

[@GSEShop]

Welcome

[@penaangel1]

Really good explanation buddy! Keep up the good work

[@GSEShop]

Thank you, please like and sub

[@n34z3r]

Brother thanks for this. Came in right on time for me doing maintenance and upgrading for my 03 LS.

[@GSEShop]

Neil Neazer welcome and thank you

[@christinegofmanas5795]

Thank you for info! My 2006 Silverado just started acting up with service 4 WD. This info will help not get ripped off

[@halfassranch8363]

What ended up being the problem? I'm struggling so bad lol we live in the country in south dakota and we got 6 inchs of heavy wet snow last night and are expecting another 5 to 12 this weekend. Of course it chooses to act up today.

[@christinegofmanas5795]

@@halfassranch8363 I just received the parts! I’m hoping it’s just the switch. It’s pretty wet here . I felt under drivers door and the grounding is crusted up. Will let you know

[@halfassranch8363]

@@christinegofmanas5795 my dash switch is supposed to be here today. I cleaned up the grounds on mine and no luck. The lights on my switch won't even flash just the 2wd light stays solid.

[@halfassranch8363]

@@christinegofmanas5795 well fuck a duck....I just installed the new switch and its still broke. On to the next thing.

[@anthonymelendez333]

@@halfassranch8363 how’d it go from there?

[@gordonellis1206]

my truck was working fine then as i was driving i have no lights of any kind on the range selector --after taking the switch out i found i had power at the switch on 2 terminals but even after a new switch still no lights-- any ideas

[@GSEShop]

Gordon Ellis I would guess an encoder problem, I have a video on that too

[@adamkorekach9936]

GSE Shop So if I trace the wires up from the actuator plug, I will find another plug to splice into like you have done? Is it easy to find?

[@GSEShop]

Adam Lucas on my Silverado it was in the center of the wheel well on top of the frame.

[@dawnwalker2461]

this is so crazy. I bought new for the first time in my life and I`m 64 years old. I looked for the the cheapest Yukon that I could find. made the deal when I picked it up it had 2 miles on it. nobody drove this truck. it owes me nothing. 345,000 miles on the Original motor & transmission. I did almost the same thing that you did. Switch, shift motor & actuator with no luck. I figured that with all the miles on her that the Transfer case was beat. oh and I even did the ground lines under the side of the drivers side door. I even ran a main ground line from the first connection where the negative side of the Battery goes to. then ran it to the fire wall then ran a main from the fire wall to the frame on the drivers side making sure that I have a good ground. watched your Video and said no way. but I just did exactly like you did and no more blinking light on the switch and no more SERVICE 4X4 on the dash and everything works as it should. I can`t thank you enough for your Knowledge on the way you chased this problem down. I have played with this for a year and a half and I was stuck on a TCCM or a transfer case. until you. I am still in shock but with a smile. Thanks again Bill

[@GSEShop]

Your welcome glad I could help

[@dstotyn1029]

THANK YOU SO MUCH! My 2005 Tahoe is having the “Service 4WD” error message. A yr ago, I replace the dash switch, fine until now. I know the mechanical parts work - it is stuck in 2WD, and I cannot change this, so the error has got to be a faulty ground somewhere. MUCH APPRECIATED!

[@GSEShop]

Your welcome, please like and sub

[@dstotyn1029]

I was on a long road trip when I posted to you 2 weeks ago. The only thing I could do was disable the 4WD by pulling the 30 Amp fuse, so now I’m in permanent 2WD. Today, I’m back at the ranch, musters my courage, and started looking for the plug you showed in your video. And ... there it was, attached to the inter fender on drivers side. I ‘spliced’ and 18 ga. wire (blue, by the way...lol) to the solid black on the firewall side of the plug, attached the free end to my firewall, and ... After reinstalling the fuse, I started it up, the dash switched cycled, as before, and I’ve got AWD, 2WD, 4WH, and 4WL AGAIN! Once again, THANK YOU! I’ve liked and Subscribed, and will tell everyone I can about your awesome video work!

[@dstotyn1029]

I’m having trouble with my Blend Door Actuators, 2005 Tahoe. I’ve watched replacement of these (drivers and passenger) many times. Passenger seems toughest. 1. Do you have any videos posted that address this issue? 2. How many ‘Blend Doors’ do these vehicles typically have (can’t find a straight answer). 3? 4? Thanks! DS (Surrey, BC, Canada)

[@GSEShop]

@@dstotyn1029 i do not have a video on that but I did do it once and it didn’t fix anything for me. I only have one under the passenger dash but I cannot confirm on the bigger Tahoe or suburban

[@dstotyn1029]

@@GSEShop thank you for the reply. Based on what I’ve seen, I prob have 3 Blend Doors in front part of cabin (rear area is working fine), aside from the main Mode door. I’ll have to dig in to find the 3rd, believe it’s above gas pedal (under shroud). I’m fairly certain one or all of these are my problem, because of the intermittent work/not working scenario. I’ve recalibrated. Works fine, then not so good. Anyway, I really appreciate all of your videos. Please keep up the great work. You do a great job of capturing the details on video and explaining things so a dummy like me can comprehend and take action. Cheers, DS

[@be891]

I have a 2004 Chevy Avalanche, and been dealing with 4wd issues for almost a year. One shop quoted me $900.00 and said I needed a new Actuator.(lol) The issue I'm having is the lights turn on on the selector switch at start up, but all turn off soon after, I also have service 4wd on the dash. I have replaced the rear actuator motor, 4wd selector switch, tcm, and cleaned up the ground underneath the drivers door but still have the same problem. I will check for true ground at the front actuator as you recommend, and post an update. Thanks for the video!

[@GSEShop]

So you lose all lights? I am very interested and I have my own theories.

[@be891]

Well after a few more days of frustration, I had to take my truck to a automotive shop. According to the shop it was a failed encoder motor. He mentioned that the gear pin was locked in place and a few wiring issues. This shop is highly rated in our area for troubleshooting electrical issues. They literally had my truck all day and the gentleman said more than one mechanic was work on my truck. I can honestly say I'm am glad it is fixed and finally I have my 4wd again. Thanks again for post this video!

[@GSEShop]

B e sorry I couldn’t fix it, but I am glad it is fixed. What gear pin?

[@be891]

Not sure but that's what he called it. I also have a few leaks around the transfercase seals, I wound if any of that fuild could have caused some of my electrically issues.

[@GSEShop]

B e possibly

[@carlostoru8509]

Hello friend, looking for a solution to my problem with the 4 x 4 service failure on the cluster screen of my 2006 Hummer H2 truck, I have found your video. I really liked his video and way of explaining everything and the most important thing is that he does it selflessly and this is greatly appreciated. Regardless of whether I can fix my bug or not. I have been struggling with my problem for many years and they have not found the fault, they have told me to change some parts but none in particular, therefore I did not want to spend money on parts without knowing 100% which part it was and which one. was the cause of that failure. The only piece that was changed to try as it was not very expensive, was the dashboard button panel, apparently it was solved but soon the same problem reappeared and is the same that happens to your truck. I left this failure as impossible because as up to now the technical inspection service of my country "ITV" had never put me in trouble for this failure because the truth is that my truck was left with that failure until today that I have had to go back to return to the problem of this failure because the technical inspection service of my country "ITV" in "Spain" has negatively failed me this inspection due to this failure. I have to resolve this fault as soon as possible since my truck cannot circulate without this unfavorable inspection documentation. By the way, I have already liked him and subscribed to his channel from my two KZbin accounts. Thank you very much for all your attention friend. A greeting from Spain.

[@GSEShop]

Wow never had a sub from across the pond that I knew of. The most common failure points are the encoder motor, and the ground wire on the front axle actuator. What does your switch do when you push the button?

[@frankmarti8984]

Very nice and thank you so much for your time and information

[@GSEShop]

frank marti welcome

[@Clam26]

Cannot thank you enough for this video. Big snow storm coming and my 4wd is shot. Tried splicing off the ground and it worked! Great video.

[@GSEShop]

Your welcome I am glad I could help please like and sub

[@tazztransport]

Have a 03 duramax had same iyshue this worked and with a bonus it also cleaned up the injector haze worth a try

[@GSEShop]

That is great. I never heard of it clearing injector codes

[@rockhoundgrandma1452]

My service 4 wheel drive light came on. It's on a chevy k2500 year 2000 truck. All the lights on the switch in the cab are lit up. If i turn my dome light override off, and press in and hold the 2 wheel high button, it dings and the dome light comes on. Then if i press it again it dings and the dome light goes off. Not sure where to start looking for the problem. I checked the first set of ground wires under the truck by the driver door. They appear to be ok. I haven't taken them off and cleaned the area yet. Any ideas?

[@GSEShop]

Rockhound Grandma watch the video, the easiest thing to check is the switch and move from there

[@halfassranch8363]

Great video very detailed and down to earth. Two thumbs up.

[@GSEShop]

Thanks please like and sub

[@halfassranch8363]

@@GSEShop i subed bro, just an FYI you tube changed their algorithm and now comments mean more than likes lol. That's why I'm spamming the shit outta your thread.

[@GSEShop]

@@halfassranch8363 spam away sir

[@atinKuop]

Dude you rock for fixing your problems better than a wanna supposed to be mechanic.

[@GSEShop]

Thanks, I appreciate that

[@ezblood21]

hope them wires are good looking, i might have to buy a new transfer case for my z71. this video helped alot to see which area might be the problem but still ill check all areas.

[@GSEShop]

Ok

[@GSEShop]

Sorry good luck let me know if I can help

[@phillipdillon2178]

Do you know which wire (If any) should be going to ground in the 8 pin connector at the shift motor?

[@GSEShop]

I cannot say 100% if I am correct, but if you are talking about the front axle actuator, then I would have to say none of them are going to the motor. The actuator operates independently and signals the TCCM when it is in position or when it has a problem. Same as the transfer case shift motor. The way I understand it they are two independent systems connected to the same computer brain. I have not studied the schematics to be 100% sure, but to the best of my knowledge this is how it is.

[@freecheese4143]

Thanks for advice. Note the hanging harness has a push clip to hold it up. Im troubleshooting now.

[@GSEShop]

Your welcome, my push in clip did not hold on anymore so I resorted to zip tying it up. Good luck with your troubleshooting

[@freecheese4143]

@@GSEShop I fixed my issue. In my case, somehow my alternator going out causes the Service 4 Wheel warning light AND Check System Charging.. I think bc it may have triggered partial mvmnt of the actuator ( not enough power to move it). I replaced alternator. Issue solved.

[@GSEShop]

@@freecheese4143 interesting I never heard of that one

[@chevymade8547]

Thanks for the very informative video. Just tested the switch on my 06 Silverado and It turns out to be good. Checked the pins and I have a good ground but I have no power. There is one pin that fluctuates at like 90-110 volts. Idk why it shows that but I know there really that much volts there but I figure that’s why my system doesn’t work. Do you know what sends power to that plug down there?

[@GSEShop]

Not off the top of my head and I sold the truck this year, I think it gets power from a fuse separate from the TCCM. There are two fuses one in the dash and one in the PDC under the hood. I forget which is which

[@veyhang1818]

Good morning GSE, on the fron differential actuator five pins plug. I did get signal two ground and a power wire but I did not get any signal from a "Black wire with a white stripe" on it. Could you please tell what Black/White stripe wire connect to or signal I should get? Thanks in addvance Vey

[@GSEShop]

Those two wires will have different voltages depending on what position and what is going on. When you press the button on your shift selector one wire provides signal current to the actuator to tell it to move into a position (either extended for 4wd or to retract for 2wd). The other wire sends a signal to the computer to inform it of what position the actuator is in (either extended or retracted). Unfortunately I cannot think of a way to check these two wires with the device unplugged. You can either pierce the insulation of these wires and check for different signals when the button is pressed and if there are different signals when the actuator is in position, but I highly recommend against this as you will eventually have corrosion in those wires and that will cause more faults. The only other real method unfortunately is to use a scan tool that can read GM tech two codes. I hope this helps.

[@veyhang1818]

@@GSEShop The only1 "Black wire with a White stripe" which I really want to know the most because all other wire are OK. Thanks for your time to reply back. Vey

[@Jason-uk4jf]

Thank you for sharing this video. I have a 2005 Silverado that keeps flashing the service four-wheel-drive. But generally the four-wheel-drive works fine. Once in a while it does not want to kick out a four-wheel-drive but after you drive it for a little bit it will go ahead and disengage. So not sure what’s going on but definitely gave me a lot of things to check.! thank you for sharing this video. I have a 2005 Silverado that keeps flashing the service four-wheel-drive. But generally the four-wheel-drive works fine. Once in a while it does not want to kick out of four-wheel-drive but after you drive it for a little bit it will go ahead and disengage. So not sure what’s going on but definitely gave me a lot of things to check.

[@GSEShop]

Your welcome please like and sub

[@JMASTERTRACTORS]

Hey just wondering how did you get the switch to start actuating the motor. My truck (04 suburban) does what your truck did in the beginning of the video. The 2wd light on switch stays on and the buttons don't do anything. Switch is new.

[@GSEShop]

Did you watch the whole video?

[@palmerkarr]

This is a great video man thank you. I have a 2006 Chevy Avalanche with the Service 4wd warning. It only comes on intermittently, and when it does the Auto 4wd light comes on. When this is happening the truck with shift into 2Hi, 4hi, but not 4lo. If I shut the truck off and back on I am able to shift into 4lo. Any idea on what this could be? Thank you again so much for your time.

[@GSEShop]

Check the wires to the shift motor, and if they are ok I would look into changing the encoder

[@dancastillo7126]

My 03 avalanche goes in 4hi only when key is on the "on" position, but not while truck is actually on. Then it doesn't go back to 2hi. I'd have to truck off truck then put key on "on" position once again in order to put back in 2hi. 4lo doesn't engage or makes noise at all. Any ideas, could it be the switch buttons. (I already replaced tccm andnl actuator)

[@GSEShop]

Test your switch because it is easy but I think you have a wire problem

[@CThames90]

Hey man. I have another question for you. My truck is losing power in acceleration and even delaying when I push the gas. No codes related. I think it's a fuel issue but I'm not wanting to drop my tank if I don't have too. Any advise?

[@GSEShop]

I would test the pressure at the fuel rail first

[@devinwalker9809]

checked ground, and tested switch all buttons good, but there is no sound or anything happening with the actuator while switch is hooked up in vehicle being pressed it stays in auto4wd with orange light illuminated also when you press either 2wd, or 4wd they will flash orange but it stays in auto4wd any ideas?

[@GSEShop]

my guess would be the encoder, but it is hard to diagnosis from here

[@JC-ci3eo]

Your video is awesome. Nice explained video.

[@GSEShop]

Thank you