2008 GMC Yukon XL Electrical Issues.

First make sure battery is good,check connection,s at the starter it self,then check the alternator,connection,s,then check the alternator to make sure it is charging right.

Just to add,make sure the ground wire from the battery is grounded to frame good.

I just replaced the ground cable from battery. It is grounded well to the frame. I had the alternator checked at the parts house and they said it was fine, but battery was a little low. The battery is about 1 year old. It was a warranty replacement for another battery that was about 2 years old.

I think you may need a new battery.

Thanks for your replies. I will check it. Let me ask you this. Once the vehicle is running, shouldn't the laternator and voltage regulator supply enough power to operate the electronis without a battery? I know in the old days, you could take the battery out once the vehicle was running. Don't know if that's still the case with all the electronics now days. Reason I ask, there are time when my voltage gauge will drop from about 14 to about 9 while the vehicle is running. Lights will dim, wipers will move slow, etcetera. I have no doubt the battery is a liitle low, but is that the cause of the problem or a result of the problem? Being able to jiggle the negative battery cable when it loses power puzzles me. The battery should either be dead, or not. This is why I thought it might not be a battery problem.

Not with all the power assccoeries you have in the yukon,alternator will not tote them alone,have to have good battery.

All so have the alternator checked again,weak battery may have made it weak all so.

I had the battery checked this morning and it has a bad cell. This does not suprise me as this will be my 3rd battery in 4 years. The alternator checked out fine. I don't think the bad abttery is the cause of the problem, I think it is a result of another problem. I have done a lot of searching and finally found where someone else was having the same problem, but no solution. It can be found here. http://www.tahoeyukonforum.com/forum/showthread.php?t=27420 People have had the BCM reflashed or replaced, replaced the mega fuse, replaced battery cables, alternators. I'm at a loss here. Any advice?

I am having the exact same problem with my '06 Yukon XL Denali. It started last Thursday with the truck having no power at all, not even lights on the dash. Replaced the battery and it started instantly. My wife just called me to tell the truck is completely dead again, nothing will work. I don't know what to do. I've heard of the starter solenoid, fuse, battery, ignition, etc. I'm trying to avoid the $400-$500 service bill but cannot find any fixes that seem worth pursuing. Any help would be very much appreciated.

I am having the same problems with my 2008 Yukon Denali XL. A friend of mine has a 2010 Tahoe and he said he was having the same electrical problems. I came upon this forum because I Googled to find a solution. I been to three different GM dealers and since the problem doesn't happen while I am at their shop they tell me everything is fine. EVERYTHING IS NOT FINE. Sometimes I walk to my car and none of the electronics work. I wait about ten minutes and without me doing anything other than trying to start again everything works normal. I bought a new Optima battery and I still get the electrical problems. In the past few months my Yukon electrical system has shut down on me three times while I was on the highway. The meters will go crazy and the radio and A/C goes out right before all electrical goes out. I had to pull to the side of the road and wait a few minutes. Then all of a sudden everything comes back on. I would like to know what the problem is so I can get it fixed. I don't want to pay for repairs taht do not fix the problem.

My 2008 Yukon XL Denali had the same issue of being completely dead out of no where. I could fix it instantly by wiggling the ground cable (you could here a click) and all would come back to life. I replaced my ground cable w/remote wire (pain to get to the end of that wire where hooks to front of frame). I haven't had the problem since. Since I have done that now the right front turn signal light and left front head light and fog light dim at same time intermittently. I have replaced all on both sides. I'm wondering if the new ground cable is bad or not big enough (cheap part)? If anyone has an idea on that please share, I'm pulling out what little hair I have left with the electrical gremlins.

Forgot since the ground cable repalcement it also says my hood is open sometimes. My wife ran the wiper fluid most of the way out and now they don't completely shut off.

I'm having similar problems with my 2005 Yukon xl denali. I have to jump the truck with a portable battery charger every time I start the truck and, when I turn the truck off, it loses all power. The truck is completely dead until I jump it again to start it.

Oh. I forgot to mention. I have a brand new battery in the car and the car goes dead after I cut it off after having to start it with a portable battery charger. I've put in 6 new batteries in the last 6 months. I've had the alternator checked 3 times and am told that it's fine but the batteries keep being killed.

It was my main ground cable, my nagging issues were cause by a small ground wire that is bolted to the frame with the remote wire from the main ground cable. When I replaced mine the first time, with limited vision to the remote wire buried at the front of the frame I didn't notice that the bolt was holding an additional ground for other items in the car. Once i noticed and re-grounded ALL of my electrical issues stopped. I haven't had any issues since. If you want to save a ton of money and are slightly mechanically inclined, spend the $40 for a new ground cable and replace it yourself. If this is the problem and you take it to the dealer, it won't show up on any test if it's not shorting at that exact time.

@TK76 That is interesting. When I replace my ground cable, I actually grounded it to a new spot on the frame because I couldn't trace where the old one was attached. It looked like I would have to remove the front bumper to get to it. I didn't realize there were other cables that terminated there as well. I will look into this. Did you have to remove the bumper to gain access?

For better visibility it would be nice, but way to much work. The wire runs down the top of the frame rail and goes over the front and bolts to the front of frame. You have to access from underneath, but nothing to remove. You need a small/short 10mm open/box wrench. It's hard to see (will need a light of some sort) and can see the threaded end coming though the frame. If you position yourself right ( I laid parallel with the bumper with my head towards driver side looking towards the passenger side. You should be able to just see the bolt head from there. Jack up the front to give yourself some elbow room. Its a tight fit to get to the bolt so have some patients. Hopefully this helps you out.

I'm definitely going to look at this, thank you for the information. I'll let you know how it goes.

I'll have to take a look at that, thank you for the information. I'll let you know how it goes.

Did everyone trade their Denalis off or did someone find a fix to the issue?

I just bought a 2003 yukon xl and I'm having sporadic electrical issues. It always starts with the ABS light coming on and then it will dead pedal while driving and the Reduced Engine Power light comes up on the dash. I can completely restart and it will run fine for a period of time. It's even caused the locks to act whacky and the guages to shut off. I've messed with the ground cable and this will sometimes solve the issue for a short period of time. Usually when I hit a bump at some point down the road the ABS light will turn on and the process starts again. It sounds like a ground issue to me and I've checked the grounds that I know to, but I was told by a good auto electrician that it is not. Any help would be appreciated.

I'm not sure if yours falls in the right time period for the problem that I was having. I believe it's 2007 and newer. The ground cable looks fine, but it eats itself from the inside. A new cable through Napa or Auto Zone is like $45. You don't want to just throw money at it, but it's a pretty cheap test considering electrical issues can be extremely expensive. If you go that route be careful if it grounds in two spots.The second ground can have multiple things attached to the same spot that are hard to see.

Did ccup ever fix the problem? Just bought a 2002 yukon. Worked great for a week now dead. Is the main ground wire a solution?

Mine's an '06 which is just like yours Eetee so I would bet it's the same issue. I could not find the second ground wire so I have not been able to fix the issue.

Would any of you be interested in participating in a class action suit? Clearly, many of us experience the electrical problem which depletes the battery in the GMC Denali.

Just bought a 2003 GMC Yukon XL. Every once in awhile the vehicle won't start. Completely dead. I try it later and it starts right up. Can't figure out why!! We have come to the conclusion it's the theft system. I tried starting this am by reaching my arm in, dead. Got in, still dead. Everything's dead like no power at all couldn't even lock doors from inside. Had to manually lock with key. Came home later. Tried it again, after googling a few things. Got in the seat, still dead. Very frustrating. About an hour later I tried one more time. Got in, shut the door, as soon as I shut the door I heard a noise, and the gauges moved and battery indicator came on. I put key in ignition, turned to on and it started right up!!! We've concluded, we have to be in seat with door shut to start it. Otherwise it shuts down completely in a anti- theft mode. All the times I tried starting if I was in the seat, I had the door open. Crazy!!

Don't seem to have the same results. Will keep trying. Class action sound tempting.

I have a problem with my 2007 Yukon Xl. It will sporadically cut all power. I started wigging wires and found that if you wiggle the wires coming out of the fuse box it will click and turn back on. So dangerous. I have not taken it yet but need to as now I am also having misfire problems as well.

Hello All I have a 2009 Denali XL and have the same problem loss of power until you wiggle the negative cable then comes to life. I replaced the negative cable cleaned all the leads even the front bumper (that has 2 of them) but now same thing again. I have not gone to the dealer yet, any help would be great. Law suite sounds good to me thats for sure.

I have been having this problem also. I have a 2008 Yukon, and sometimes when I get in the power door locks won't work, there's no sound when the key is put in (the ding, ding, ding,) absolutely NOTHING on the vehicle will work. Then I can go back ten minutes later, and everything works fine. I have noticed that the clock is always reset (like the battery has been dead....eventhough it starts up just fine some of the times when this happens.) I have already taken it to the garage twice, but it has done no good.

I just purchased a used 2007 Yukon XL Denali. The electrical comes and goes as in totally gone black then comes back on. This time has not come back. Hooked up to jump it. Did not help. Bought a new battery as the existing battery is 5 yrs old, before I install it thought I'd investigate if others have this same issue. Previous owners of this Yukon said there was something up with the electrical system yet every time I test drove it I found no proof of the problem. Well I have now inherited their "electrical problem"...I will give the ground wire a try. Yet this has happened 5 times in 4 months. I do believe a class action is in order. This is not just a coincidence all these folks are dealing with the same electrical problem. Im in...Where do we begin? Gus

I have a 2008 Yukon XL I bought just over a year ago and only had 51,000 miles on it. I thought I was getting a great car but now realize its defective. I have been having the exact same electrical issues for the past few months and the dealership always says they cant find any issues. Very frustrating. I think a lawsuit is a really good idea!

Where do we start.Are any lawyers having the same problems? How can this many of us be having the same issues with no answers. There are so many of these models on the road. Is it just certain ones built on Fridays???

@TK76 is your car still having no issues after you replaced the ground wires? Just curious as it seems your method has had the best resolution so far.

Replacing ground wires did not solve the problem for our 2007. One of many things we tried. We bought and used extended warranties to replace all sorts of things until, due to mileage and age, there were no more warranties available. Now the knee-jerk diagnosis is, it's the battery. So standard fix is replacing the battery until it happens again. We have a warranty on the battery and have not had to pay full price for a new battery in years because they have yet to outlive the warranty. As for a class action suit, I contacted 3 law firms in PA (where we bought our car) and the gist is, unless some of us can prove we have suffered egregious physical injury as a result, there wouldn't be enough in damages (read: $ to be made) to interest the lawyers. The ages of our cars also deterred them. As one said, "We have reviewed your inquiry. Regrettably, we have concluded that we will be unable to provide representation in connection with this matter. Among other things, a substantial period of time has passed since your purchase of the vehicle." We have had electrical issues with this car since a month after we bought it (new.)

My 2007 Yukon XL acts very similar to the problems that have been talked about on this tread. I noticed a little rain is able to somehow get in on the passenger side of my vehicle. I am wondering if that is contributing to my inability to turn on the car....is there a short because water or residual water shorting out the system?

Hey guys we had this issue with our 2010 yukon...some of you may have bad grounds...but ours would stall out and set off all sorts of alarms while driving or coming to a stop...so what I did was pull the air cleaner and use carb cleaner to clean the throttle body plate and maf sensor...see what,was happening to us is when you let off the gas and the throttle plate closes the extra gunk would choke the engine for air this would then cause a low level misfire hence the low voltage and all the problems associated with it then the computer would try to compensate . Since I cleaned it i haven't been able to duplicate the problem I cranked on everything I could and still was good to go.

Our 2010 Yukon is going crazy. It's a little possessed, I'd say. The first thing that happens is the stabilitrak light comes on and the car lurches a bit. Then eventually, the air bag light comes on. Then the door locks start clicking on and off. The engine begins to lose power as though it is not shifting out of low gear. I took it to the dealer. They said the battery was bad. We got a new battery. It worked for about 3 months and now it starting again. I did notice leading up to the events that the alternator gauge is to the left of center most of the time, but not always. It seems to happen when it is really hot out and the AC is running. But that is just my guess. The dealer was supposed to have checked all of the grounds as my son told me that was probably a bad ground wire. They said they were all good, but bad battery. We are going to the parts house to check out the battery and the alternator. If anyone has a clue, I'd appreciate your help! Thanks~

Had the exact same reaction as you, “my 2007 Yukon Denali XL is possessed!” the door locks start clicking on and off, and in our case, battery dies. This started a few months after we bought the car NEW. In our case, it usually happened after I had been sitting in the car with the engine off for a few minutes but with either the radio still on or talking on the phone (which is installed in the car). A bad ground wire is an intelligent deduction, but in our case was not the problem. There is a computer error that occurs with this car. The computer won’t “let go” –something is allowed to stay on when you turn off the ignition. In 10 years,no one has been able to fix it. We just keep getting new batteries with warranties on the batteries, so we can replace them at no/low cost when they die.

I ended up replacing the main ground too it's a poor design. I also hunted down the other 3 ground wires pulled them cleaned them and out then together...the one on the frame on front passenger side is tough but I have yet to have any problems with my yukon yet and it's been 2 weeks it's a daily driver

I didn't drive the car for two days. It started right up and we drove it to the parts store where they checked both the battery and the alternator and said they were both good. So, I guess we just wait until it happens again. SO frustrating! I guess i"ll give the car a way and buy a new one! Just got it paid off a year ago. It has 86,000 miles.... CRAZY!

Replace the main ground...it may look ok but it's of poor design...next time it dies...go straight to it and wiggle it on the engine side of it...thats what I did I had the same issues alternator was low charging with a/c on lights would come on in the dash and stabilitrak light would come on too. You'll notice the wire is just clamped in to the piece that goes on the block it's exposed so it corrodes..and it moves wiggles itself that's why it's intermittent...

On my 2011 Yukon it was the Theft Deterrent Sytem issue. It has been 2 yrs since I had it fixed and I have had no issues.

I have a 07 denali xl with the same problem. Wiggle the ground wire and it starts back up. I'll be checking into replacing it to fix.

I recently a few months ago purchased a 2012 Denali XL 1500. After the first month of owning the vehicle my dashboard lights and electrical system for air conditioner, locks, the motorized external step/running boards would all reset sometimes 7+ times in 30 minutes while either starting or driving the vehicle. I took it to the local GMC dealer service shop, where they stated they tightened lose fittings around the battery area. Got the vehicle back and it worked fine for one week. After that week my family and I attempted to take a long drive to Dallas, half way there the system started resetting while driving with my wife and kids in the car during over 90 degree weather in the middle of practically no where, no cell service in the particular area we were at during traveling, the transmission would slip and do a super hard jerking engaging/disengaging and the vehicle would slow down while everything started resetting, AC cut out and we were forced to pull over on the side of the road where I let it sit for about 10 minutes with the ignition completely turned off and key removed. I'm glad it started back up after those 10 minutes and everything worked enough to make it back home safely, experiencing minor factory resets on the way home from the dashboard and AC unit. Made a U-turn to head back home and canceled my family plans due to the issue and took it straight back to the GMC local dealer. They then proceeded to replace the grounding wire (keep in mind I paid a fee already for the first repair which didn't fix the problem) so with the grounding wire replaced, the vehicle was working again at the moment I paid over $300 dollars for this second service.... two months go by, and then the issue starts happening once again everything resetting, codes randomly going off, dashboard and AC settings back to factory during my transport to work. I specifically bought this vehicle for my wife and kids to enjoy and family trips. I serve in the United States Army, and this vehicle we're having to pay for repairs which is turning into an on-going incident with out any remedy in sight. I have since the third time of this issue occurring on my way to work, returned it back to the local GMC service shop, and they currently to this day of this post have it in their possession right now and this is the third week it has been with them in the shop with no issue identified. In the shop for approximately 20 days now. This is really frustrating, not so much for me because I can tolerate a lot and I like to be understanding, but for my wife and two kids and about three weeks in for repairs, having paid for service twice that did not fix the issue and being advised the issue is unknown, unresolved and on-going on this third time around, it's starting to take its toll.

I have an 06 Denali. Just had a new Jasper put in. Now the electrical is crazy. Radio has red light but won't go on, Press all locks open and it takes 10 seconds. Back windows make a little noise but then do not go down, Gauges all misreporting, empty light stays on, not engine temp. And on and on. I am trying the ground wire fix.

A follow up on the above report. Most idiot lights are on. Evey function is delayed except the drivers window control. If I open the door with the key in the ignition I do not get the ding ding ding for about 10 seconds. Also if the radio is on and the car was just shut off opening the door does not kill the radio right away. It is like the computer was being overloaded

I have had a similar issues mentioned in this thread. I have a 2008 GMC Yukon Denali. It's a rebuilt title. It was in a side impact collision shortly after it was purchased in 2008. Somebody bought and "fixed" it and sold it under a rebuilt title. I bought it from an acquaintance who was the third owner. He had had issues with the suspension other minor things and had the service records. I owned it for almost 6 months when I took it on a dirt road and had all sorts of "stabilitrack" and "traction control" messages cam on along with "reduced engine power". I took it to a dealer and they told me is was a accelerator position sensor, that they replaced for about $400. However when I picked it up it did the same thing. They looked at it again and there was a damaged wire harness the plugged into the PCM. They zip tied it and said I should be good, but that some of the wires were worn and exposed and that I really need to rewire the vehicle for $2700 to be sure it didn't give me problems again. 6 months later the same thing happened while my wife was driving it on the freeway with my two boys in the car in the dead of winter. I took it to a local garage and they told me it was the PCM itself needed replacing for $700, did that and they called later and said it didn't fix it so they looked at the harness and decided they would try and rewire and solder the connections and also ran a designated ground wire to the frame. It worked great for about a year. Then we started having electrical issues again, like the ones described above. I replaced the positive and negative battery cables, cleaned all the ground contacts and recently replaced the starter. It seems to be fine now. My wife is giving it 6 months and if something else happens I am told I have to sell it. Don't tell her, but I agree. My dad has an 01 Denali that has 320K miles, been through 2 transmissions but still runs like a champ. Dependability is what I was hoping to buy and it hasn't been true so far. I have 112K miles currently and purchased it at 75K miles. in summary I suggest to trouble shoot this: Replace Positive AND Negative battery cables. Check that the ground wire for the PCM is intact and not exposed. Check and clean all ground contacts for the negative and positive battery cable. Seems to have helped my situation that sounds very similar to all the others here.

Currently having similar issues, the battery died in my 08 yukon denali and when my husband swapped it he hooked it backwards...snowing dark etc...anyways now there is no power to the vehicle we think it's just a fuse but not to sure. Fornthe person with the pcm issue this also happened to us last Halloween. We went through a huge puddle and it shorted out the truck (possessed) my husband got the part online for like 150 and swapped it himself no issues with that after wards

I have a 2007 Denali Yukon XL, 53,000 miles it had all the weird problems door locks, windows, headlights flashing, radio flashing etc...and put me down several times. I replaced all the battery cables and installed a second new battery. At 275,000 miles it has never given me any trouble since. I connected second battery ground to alternator bracket and positive to existing connector on wall behind the battery. Run new cables on original battery to starter and ground.

2003 yukon XL, Battery doesnt get low enough to keep it from starting, but it sure as hell resets the ecm and I have to do the drive cycle all over again. I have browsed forums and the most common fix seems to be grounding issues.. there are 3 grounds on mine. one is under the drivers seat on the frame of the car.. the other 2 are on the back of the engine block and you can only get to them if you have the intake manifold off.. they need to be taken off sanded then reinstalled with a little bit of dialectric grease on them.. it fixed the issues on mine

Hi all. We have a 2012 GMC Yukon XL Denali (that my wife primarily drives). She has been intermittently experiencing alot of the same issues being described​ in these posts (she would be driving and the vehicle would seemingly go into limp mode with the entire electric system shutting down... While this didn't happen often, she was really worried about this happening with the kids in the car). We spent alot of time at the dealership and they were never able to come up with anything. It happened again and we brought it back to the dealership and this time worked directly with the service manager. The scan didn't show much, but did show a problem with the theft deterrent system. After brain storming with the service manager, we came to the conclusion that the electrical transponder inside the key went bad which was causing the issues with the electrical system. Hopefully this will have fixed the issue... Time will tell... Fingers crossed.

Followup. Solved. Mine turned out to be a short in the network. It was coming from the radio to steering wheel interface box. It was clogging up the network traffic in a bad way. Found by systematically unhooking parts of the comm chain.

I have a 2012 GMC Yukon Denali, and these same things have been happening to me the past year. Recently, while on a long trip, it started happening more frequently and yesterday while driving down the road the locks started going up and down in the car and every light started to switch on and off .... then after parking at work and coming back to the car, it was dead. AAA mechanic jiggled the ground wire and it started again ... crazy. Has anyone had anything definitive on this?

I have the same issues that were posted here, and finally filed a complaint. Go to NHTSA.GOV to file. This is a big safety issue, there is a recall on electrical issue you could check if yours is one of them by putting in the VIN of your vehicle if yours is not included just line mine, you need to file an official complaint. Hope this will help us solve this issue and have them fix the problem.

I have a 06 Denali and the electrical has been cutting out and a bunch of random things. Took to a local shop and they told me the 'master computer' needed to be replaced, about $800... Anyone else have any knowledge or experience with the 'master computer'?

Replace the main ground to the battery. Even if it looks good. They break internally. I did this two years ago on my 2010 yukon and it hasnt had an episode since. It would die after it shut off and would have reduced power and intermittent electrical issues I checked the ground cable no corrosion and it had a brand new battery but I replaced it anyways for 13 dollars and it did the trick. I noticed on my 2015 I recently sold that they changed the battery connectors

I have been fighting this issue for a long time.... I feel certain this is related to the Frame Ground... It has a new Ground Cable, New Battery, New Alternator.... Once I got the Professional Mechanics out of the way, being an Aircraft Mechanic specializing in Avionics Electrical, I inspected the ground on the frame and found 3 distinct items of concern. 1.) The bolt was sort of corroded and did not look like a good conductor 2.) Both wires at that ground location were oxidized 3.) The area under the ground was greasy and grimy... My solution was simply, 1.) Cleaned/Polished the bolt 2.) Cleaned the surface and polished with 2000 grit sand paper 3.) Cleaned/polished connectors 4.) Reinstalled using Dielectric Grease My meter readings are now rock solid "0" Ohms... Before was floating all over the place.

So, has anyone found out a solution?

I had the same problem and found that if I disconnected the battery (new replaced several times) and touched the positive and negative cables together for 15-30 seconds and then reconnected the battery everything was back to normal. This led me to believe that something was resetting Long story short... Body Control Module was apparently bad as you could wiggle the harness and cause the fault to occur. There does seem to be a connection with the radio interface as this is the first indicator that somethin is amiss, then the gauges, door-locks and everything else. It is extremely frightening when traveling at 65+ MPH and you loose complete electrical power. There should have been a recall.

Can anyone help me understand my issue . I have a 2008 Yukon SLT , it seems when it rains my inner controls , IE. gauges , radio , a/c , dummy lights turn off and on. It seems to only happen when it rains . When it's not raining everything works fine .