Chevy GMC Code C0378 Service 4X4 Message 

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

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

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

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

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

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

Thank you from North Carolina!

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

Thank you. Very helpful!

Thanks Tim, appreciate the Vid.👍

That's a fast lift you got there Tim!

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

Also, very helpful. Thanks for making this video.

Again great video tim as always keep up the good work

Good job. Have a great Christmas!

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

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

Well explained.Your the man!

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.

Thumbs up Tim!

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?

Thank you for sharing 🙏🏼🙏🏼🙏🏼

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

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

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

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

nice to see ya again good repair there

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!

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?

Thank you!

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

Thank you so much.

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.

Good job keep up the great

Good job doctor, the patient was healed.

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!

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

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?

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

My avalanche 07 is stuck on 4low any suggestions thanks

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

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

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

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?

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.

SWEEET VID 🚹 👍 👍

Hi sir how much is the costs for that service?

What do they use on the roads up there?

I feel like a mechanic now you da man.

Da G.O.A.T

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

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.

still use air ratchets????

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

Man I wish I was in Alaska 👍

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 🤙🏽

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

Lots of snow there!

👍👌💪

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!

I have a question

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

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.

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

Doc this also apply to a 2014 1500 Silverado 5.3?

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

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.

4x4 traction module failure... Help

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 :) )

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

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!

Affected by cold weather ? How fragile !

WZ WSTH4K