Chevy GMC Code C0378 Service 4X4 Message

In this video I deal with a Chevy Avalanche that arrived with the customer complaint of intermittent no 4X4 operation and a service 4X4 message on the drivers information display. After pulling a code C0378 I look deeper into the 4X4 control system in attempts to locate the cause. I'll show the process for testing and replacing the front differential actuator as well as servicing the transfer case and front differential fluids. Watch this video for more diagnostic information and the fix!
This information is helpful for most late model Chevy, GMC and other GM trucks and SUV's with similar symptoms/codes.
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[@fieldsofomagh]

The people of Anchorage are lucky to have such a competent mechanic as yourself, keeping them wheels rolling.

[@bwilliams3227]

Thankyou, I really appreciate your help. Not just on this one video, all of them. You teach me alot

[@kylependleton1987]

THAAANK YOU SOO MUCH. IM GONNA DOO ALL OF THESE TO MY STEPDADS 2011 SILVERADO 5.3 I LOVE ALL UR VIDS UR VERY CLEAR WITH YOUR WORDS. THANK YOU AGAIN. FROM A MAINE GUY

[@ReeseMoore]

Thank you from North Carolina!

[@shamsqarizada2083]

Thank you. Very helpful!

[@kc4tlm]

So, this video taught me I need a lift. :-)

[@edb.3313]

Thanks Tim, appreciate the Vid.👍

[@goldenking1055]

Thank You For Video Now I Know What My Problem Is .....Keep up The Work

[@kc4tlm]

Also, very helpful. Thanks for making this video.

[@breakingthegrain3425]

Thank you! Been waiting for you or Eric O. to do this one!

[@ThecardoctorTV]

Oh good timing then. Seems like a common deal.

[@mikeanderson1994]

Again great video tim as always keep up the good work

[@ThecardoctorTV]

Thank you!

[@Dankkize]

Well explained.Your the man!

[@ThecardoctorTV]

Thanks

[@zach5301]

That's a fast lift you got there Tim!

[@SteveRobReviews]

Well done buddy. Wow that was an easy actuator to replace, nice design . 👍👍

[@ThecardoctorTV]

Yes easy but problematic. Seems simple enough but for some reason they crap out all the time. This was almost a year ago in Feb. and this one seems to be fixed! I guess I need to get some new material for videos.

[@Badgertronix]

Good job. Have a great Christmas!

[@cs9064]

My man you deserve more subscribers on ur channel.😢 great service tech

[@BigDog50001]

Thumbs up Tim!

[@davidsupulver6408]

Thank you for sharing 🙏🏼🙏🏼🙏🏼

[@glenharper3136]

O.K. Tim Good to see another new video.

[@ThecardoctorTV]

Thank you. A few more on the way!

[@547Rick]

Nice! Love the Chevy videos because I have a lot of them. LOL!

[@ThecardoctorTV]

Me too. They keep us in business as well. Haha.

[@tlcbear2]

nice to see ya again good repair there

[@ThecardoctorTV]

Thanks. Good to see you as well. Have a happy day!

[@wyattoneable]

Preventative maintenance is probably more important than ever now that so many sensors are involved. Or? Have a blessed Christmas Tim and be good up there. Hope to get back up there one day.

[@ljgarrison6910]

It's the little touches, like cleaning a part down after fitting that the owner may never see - top guy. Wish he was in the UK

[@billclark6489]

Thank you!

[@garyclemons2689]

Good job keep up the great

[@ThecardoctorTV]

Will do thanks.

[@benshropshire9969]

Thanks for the video! I had the same intermittent problem. Mine turned out to be the ground located behind the driver's side front wheel

[@pcdetail602]

Hey what ground was that ?

[@23CarlosG]

Great video will be doing this on my 2009 Tahoe this weekend hope it resolves my issue and the service 4x4 message clears

[@OfficialRonnieHerron2]

Did it?

[@shermankearns200]

Thank you so much.

[@ThecardoctorTV]

You bet

[@LaramieJim]

Last winter my 03 Yukon 2500 had that same code when 40 below. It warmed up to 30 below and 4wheel ran like a champ. Strange things happen to mechanism at low temperatures. Merry Christmas Car Doctor!

[@ThecardoctorTV]

Indeed. We are slow this time of year unless it gets cold. When it’s below zero for very long we get all kinds of repairs. Lots of electrical and mechanical failures.

[@putradjaja8196]

Is this for middle east market ?

[@davidd8435]

Good job doctor, the patient was healed.

[@ThecardoctorTV]

Minor outpatient procedure.

[@joeclark8029]

hey there great video. what does the water in there have to do with setting the code im sure there is a good reason i just dont know if u could answer that would be awsome as im trying to learn

[@tubby687]

I have a 2018 4wd Sierra and it says “service 4wd” when I put it to 4wd. It engages it but it takes about 60 seconds to engage. The service 4wd message pops up when it engages and disengages. I’ve always kept it on 2wd. Any places I should look for what’s causing this?

[@timcoe457]

Thank you, my 2003 keeps throwing the service 4wd message and I’ve been trying to figure out why. Most of the time it does go into 4wd but occasionally it doesn’t when 4wd is first selected.

[@maudsquad]

I had this happen on my 2000 Suburban all the time. In my case, it was a bad switch. It's a common problem with that generation of Suburban/Tahoe/Sierra. There's usually no problem with the actual 4WD, just the switch itself. The switch can be found online for $25 and it takes about 3 minutes to install. It's an inexpensive gamble.

[@user-bu6oj3sg8v]

Da G.O.A.T

[@smms1276]

SWEEET VID 🚹 👍 👍

[@EXOVCDS]

Pattern failures can save the customer diagnostic time charges... replaced a crank sensor yesterday on a VW. If it sounds like a duck, looks like a duck and walks like a duck!

[@pcdetail602]

Great video. I been having a issue with mines where the stability track light and check engine comes on and traction control and my tired be feeling funny and when I park and put it in parking and play with the 4by4 nob it does a clunking sound and then drives normal. Do you think it can be the actuater or a ground?

[@bigdrewski86]

This was very helpful. Can you give a round about price for this service?

[@gwaite2955]

Any ideas for this? C118D-13 Transfer case control module (TCCM) Front axle actuator control -circuit open

[@casecarter77]

I feel like a mechanic now you da man.

[@thuggmtz]

My avalanche 07 is stuck on 4low any suggestions thanks

[@bigjohny702]

I have a question.... What should I do if my Service 4wd message light is on all the time on my 07 yukon? I serviced the fluid for front differential, rear differential and transfer case alreade. I also checked, and my 4wd ingages everytime I change it to 2wd, 4wd and the other option on Neutral works aswell. However when I drained the oil to the Transfercase, only like 5 drops came out, so it was empty. any info is greately appriciated.

[@Chuck-hg1pg]

Do you have to relearn the vehicle after you put the actuator in?

[@RICOCORTEZ78]

Great job thanks for the video, whats the cost of a service like that in 2008 silverado?

[@jamesguralski5156]

Yeah right my 2009 silverado is popping and clicking. I changed the transfer case and new u joints for from drive shaft! Still popping, next change the actuator in front then t case actuator!

[@tonymickens8803]

My light just Keeps Blinking when I turn it to Auto for about a minute then 4 wheel service pops up, Works Fine in 4 lo and 4 high, I changed the actuator and checked connections, fluids Always maintained and Still Does It? @The Car Doctor

[@scribble4766]

I have the same problem with my 08 SLV 4x4. When I got the message, it was in 4x4 H. It will not come out of 4x4. Would the actuator cause the same problem? Very hot here in N.W. Kansas. Also, what were you using to clean up?

[@MattBaker-zd8nq]

I have a 2017 Chevy Silverado with an 8 inch lift and 37 inch tires. I had to use the four-wheel-drive yesterday because of the snow but when I got up this morning a light come on says service four-wheel-drive system. I hope I don’t cost a normal leg to fix.

[@Sara-gl8ue]

5:55 - The exact reason I no longer eat at Taco Bell

[@adrianrodriguez2646]

🤣🤣🤣

[@genesloan3175]

Is there any specific way to diagnose whether the Actuator Motor (what you replaced) is actually faulty if I don't have a diagnosing computer?

[@JamesJackson-ty9uk]

Do your front axles still turn even if your selector is set to 2wd?

[@jamesguralski5156]

Hey thanks for vid! Any part # for the actuator?

[@ThecardoctorTV]

Dealer will have that. Thanks

[@nathandelmar2608]

replaced noisy transfer case due to clutch issue and then service 4wd with same code tried everything ìt was then a tccm behind headlight switch bought used one so no programming invovled no need to change fluid that cost 10.00 a quart

[@nickspeenburgh136]

Lots of snow there!

[@ThecardoctorTV]

This was footage from Feb and actually we have 45F and all our snow is melting right now. Lame.

[@mauiequipmentservice]

still use air ratchets????

[@scotta8494]

looks like an axle seal is leaking also. Is this one similar to an 06 Trailblazer? Looking at getting one where the front diff is not engaging.

[@ThecardoctorTV]

Oh boy, those trailblazers are one strange system. So many front diff problems. Is it the model where the diff passes through the oil pan?

[@scotta8494]

I am not 100% sure. It has the 4.2L in it. I have seen some posts where it could be a broken fork on the passenger side extension where the actuator locks. My daughters 94 K1500 had an axle seal replaced and a thrust washer slipped down and was not allowing the diff to engage. Hoping it is something similar or as easy as an actuator...

[@justinp8946]

Man I wish I was in Alaska 👍

[@ThecardoctorTV]

Well today it was 46F so it’s certainly a mild place to spend the winter.

[@justinp8946]

The Car Doctor I’m surprised it wasn’t colder. In Arizona, it was almost 80 F. Too warm for me

[@crescruz8007]

The Car Doctor My wif's 2001 GMC Yukon makes a really weird noise I disconnect that wire and the nose stops but when I connect it back it makes the noise what should I do?

[@ThecardoctorTV]

Yikes. I would look at the fluid in the front diff and see if it has metal I guess. It even makes the noise in 2WD?

[@MattBaker-zd8nq]

I sure miss the good old days when they had a shifter to let you know when it was in four-wheel-drive this electronic shit is for the birds

[@manuelvazquez2401]

👍👌💪

[@joeldejesus8263]

Hi sir how much is the costs for that service?

[@marclarion9373]

Great information. I have a question that goes along the same lines as your video. I started getting this after I got my truck lifted. I’m getting Service 4WD and Service Stabilitrak messages on my 2018 Silverado 1500. What could be causing this and how do I go about fixing it? Thanks and great videos 🤙🏽

[@marclarion9373]

Oh and I forgot to mention that I am not getting any codes.

[@Nutrageous27]

Did you ever figure it out ? I have a 2015 tahoe doing the same thing

[@Thundarr995]

Permanently locking up the axle probably won't make much difference as far as gas mileage goes. I've converted 2 4x4 vehicles from auto hubs to manual hubs. It didn't even make a difference.

[@lifewithernie7216]

I have a question

[@omarrodriguez9957]

My Service 4X4 message is still up and 4X4 still doesn’t work after all of this.

[@upnorth5465]

More than likely a problem with the encoder motor or the sensor inside the ecoder.

[@rusco321]

What do they use on the roads up there?

[@ramoneduardoramosvelasco1935]

4x4 traction module failure... Help

[@ThecardoctorTV]

Oh no

[@stevenwiltse9611]

Mine wont shift out of 4x4. It says 4 high but wont shoft to 2 wd

[@PurplePaintHuntinClub]

Did you ever figure this out yet? I have same problem.

[@stevenwiltse9611]

It just started working again. I think i had snow and ice built up.

[@willmckelvin3141]

I have a 2007 Tahoe and I’m having an issue with getting “SERVICE STABILITRAK”, “SERVICE 4 WHEEL DRIVE”, all of the indicator lights come on and there’s no underscore under the mode I’m in (PRND321). When this happens while driving, the speedometer, gas gauge, battery voltage gauge all fo to zero. Once I turn the truck off, if I were to try and start it back up later in the day, it will not crank and it will not start. I can take from one day to several days before it will start again almost as if what caused it has subsided for the moment. I can really use help in trying to get a good diagnosis as I’ve been actually dealing with this issue for years! I would sincerely appreciate any feedback! Thank you!

[@housemachine509]

Doc this also apply to a 2014 1500 Silverado 5.3?

[@lorenaduarte2280]

hey did you get any answer for this?

[@housemachine509]

No

[@natebathke4242]

Where would someone find the kit to turn it into full time 4wd

[@zx8401ztv]

I think you nailed the gremilin, and a needed service while you were at it :-). Thank the god of your wallet for the car lift :-D, imagine how crap the jobs could be without it. (Ok stop kissing the car lift :) )

[@ThecardoctorTV]

I would not be doing this work anymore if I didn’t have a lift! So nice.

[@nothingfree3524]

Affected by cold weather ? How fragile !

[@ThecardoctorTV]

Like me. Haha

[@willmckelvin3141]

one thing I didn’t mention: this happens when driving in the rain, going through the car wash or in any situation where the underneath of the truck is getting wet. This recently happened this afternoon and as of this message it will not crank and it will not start. Again, I’d really appreciate any feedback!

[@eltonholtjr.7591]

If someone could let me pick your brain, I'm new to 4 wheel drive. It makes noise, what could be the problem? 98 z 71 silverado.

[@haywardsautomotive6156]

Nice video Tim. We got 10 1/2" of snow this weekend near Atlanta, GA and the asylums let all the inmates out to drive but not before the citizens of GA bought up all the bread & milk in the state. The Governor called a state of emergency for Georgia and asked for emergency shipments of bread & milk. When I was in NY we prepared by getting gas for the emergency generator, propane for the heater & Coleman camping stove, wood for the fireplace, water, food, etc but here in GA nope just grocery carts full of milk & bread and the stores are cleaned out when the panic calls come someone has spotted a snowflake and not the Democratic kind :D

[@ThecardoctorTV]

Hahaha, that’s funny. It’s 45F here and most of the snowflakes are melted. Glad I’m stocked up on milk and bread!

[@miguelmacedo1926]

WZ WSTH4K