# Taillights and trunk latch not working



## bksmm (Apr 18, 2014)

A few days ago, we discovered that the trunk on our 2011 Cruze LS would not open with either the key button or the rear trunk latch. The doors were unlocked and the keys were not in the ignition but it would not open by either method.

Today, someone stopped my wife to tell her the brake lights weren't working. So here are the result from my investigations. I am using terms from my owner's manual to avoid confusion.

Each taillamp assembly has 4 lights. The backup lamps and the turn signal lamps were working on both sides. The sidemarker lamps and the stop lamps/taillamps were NOT working on either side. The trunk deck inboard taillamps also were NOT working. The center stop lamp in the rear windshield was working. The license plate lamps also worked. 

I checked all the fuses in the engine compartment and the instrument panel and they all looked good. I don't see any fuses for the rear lights in my manual except for fog lamps which I don't have. Fuse 16 in the instrument panel is for central locking system/tailgate and upon replacement, the trunk still didn't open. There's also a relay for "trunk open" that may be the problem.

I opened the trunk with the emergency handle inside. I removed both taillamp assemblies and did not see any signs of wire damage or loose connections. I removed the sidemarker lamps and the stop lamps/taillamps but did not see any visible signs that the bulbs were bad (I have not replaced them yet). I also removed the trim inside the trunk edges but again did not see any signs of wire damage or loose connections. 

I'm not sure if there is a connection between the trunk not opening and the rear lamps not working as they may not have stopped working at the same time. It's perplexing to me that the center stop lamp, the turn signals, the back up lamps, and the license plate lamps all work. Any ideas other than take it to the dealer which I will have to do if I can't resolve this.


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## NickD (Dec 10, 2011)

This is where a shop manual comes in handy to show the power distribution and key ground points. A ground is the only thing I can think of as a common denominator between the trunk solenoid and lamps. Without the manual, can end up tearing the entire vehicle apart.

Recall a Ford with a non-working fuel pump, who would ever think the ground for it was under the driver's seat.

Even my Chevy dealer no longer has printed manuals, everything is on their computer. Without wanting lay out 200 bucks for a manual. When out of warranty, would go to him and get a printout of what I needed. Saves a lot of work.


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## spacedout (Dec 7, 2010)

Probably best to take the car to the dealer at this point.


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## Jim Frye (Mar 16, 2011)

I agree that a trip to the dealer is in order. A separate question: Does the BCM control all of these lights and the trunk release?


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## blackbowtie (Jul 4, 2013)

^Yes

I also recommend just taking it in to the dealer to verify your BCM is fine.


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## bksmm (Apr 18, 2014)

Thanks for the replies. I guess the dealer is the only option. Of course they want $90 to even speak to me.


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## NickD (Dec 10, 2011)

Could hear that upper left hand relay in the IP fuse/relay panel click when activating the remote. But with this new solid state two shot relay, dead silent. If you can hear your original relay click, least you know the signal is going that far.

Read someplace the center brake lamp is on a different circuit as you side lamps, does your center brake light work? Least this is telling you your brake switch is okay. 

Manual is not very explicit on which fuse is for the brake lamps, but certainly has a number of fuses for the BCM, some suggestions are to check them all.

Five computers in the Cruze all capable of flashram upgrades, when I hear about problems like yours, would like to go down south and find a low mileage 04 Cavalier. Least everything on this car is conventional and already have a shop manual for this vehicle. In other words, it used real switches. 

Could try posting this in the as GM section, seems like a major safety issue here.


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## bksmm (Apr 18, 2014)

Yes, the center brake lamp works. I referred to it as the center stop lamp since that's what the manual calls it. I did a visual inspection of all fuses in both compartments and they all look good. I'm taking it to the dealer in the morning.


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## spacedout (Dec 7, 2010)

Let us know what you find out.


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## Chevy Customer Care (Oct 29, 2011)

Hey Bksmm, 

I am sorry to hear you are having these concerns with your Cruze. Since I am not a technician, I am unable to provide technical advise. I can certainly reach out to your dealership on your behalf. Please private message me your name, VIN, phone number, and dealership name. 

Erica Tiffany
Chevrolet Customer Care


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## NickD (Dec 10, 2011)

On several vehicles with a wiring harness going to doors, hatches, or trunk lids found broken wires in the harness. But these were older vehicles using vinyl insulation that becomes brittle with age and mostly in subzero weather. I used 16 AWG neoprene test lead wire to spice the broken wires that really solved this problem.

Could explain why the trunk lid tail lamps and the trunk release don't work, but your Cruze can't be ten years or older yet. But the rear quarter panel brakes light harness is fixed, not subject to this continuous bending.

This causes me to think when I open the driver's door in subzero weather, open it very slowly. Has a bunch of wires for the rear view mirror, the master window power window switch, the door lock motor, the speaker, and one for the illumination.

Makes me think about my first car, a 30 Olds that never had this problem, zero wires to the door, but somehow this car managed to get me there. And at times, even over 90 mph. Still fast enough for a vehicle that would be 84 years old now to have my driver's license taken away if caught. 

Do we really need all this stuff?

04 Cavalier only had two wires to the driver's door, for the speaker, rear view mirror was mechanically adjusted with an inside lever, it worked. Wife wanted me to add remote entry so added two more wires using a neoprene heater line cord. Also spiced in a piece of this cord for the speakers. Windows were manual and even worked with a dead battery or the keys in your pocket. We survived putting over a 100K miles on this car. And never had any problems like this.


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## 99_XC600 (Feb 24, 2013)

Ok, you should start with the basic troubleshooting first.

1.Grab a multimeter. You can pick one up at Harbor freight for less than $10.
2. Identify the correct fuse for the brake lights in the PDC in the car.
3. Remove the fuse. 
4. Using the meter set on 20VDC measure for voltage across the terminals when the brake pedal is pressed.
5. You should read 12v


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## bksmm (Apr 18, 2014)

My dealership let me know the bad news. He said both the BCM and the trunk latch need to be replaced. The tech thinks the BCM went bad which caused the trunk latch to go bad. The BCM will be 468 + tax and the trunk latch 169 + tax. 

By the way, the taillights and the trunk latch are the only things not working on the car. Nothing happened that we know of that caused them to go bad and I have never done any modifications to the car. My cruze is a 2011 with 55,000 mile on it. I won't buy another car that relies solely on electronics to open the trunk.


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## Jim Frye (Mar 16, 2011)

Ouch! I have come to the conclusion (against my prior inclinations) that an extended warranty for these new cars is becoming something that needs serious consideration if one is to keep them for very long, like beyond the manufacturer's warranty period.


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## NickD (Dec 10, 2011)

I know this about the trunk release solenoid, and is a solenoid, a coil of wire wrapped around a form with a movable armature on the inside. Excited with 12 V by a relay and is not directly connected to the BCM!!! But this relay acts like a buffer. Either the remote or the push button on the rear of the trunk can activate this relay. On previous GM cars, I have found poor solder connection on this solenoid. Burn some smoked flux off of it and as good as new.

I sincerely doubt if the problem is in the BCM. On BCM's or PCM's that directly drove an inductive load that shorted out, would take out a buffer transistor on the inside, these normally run a nickel and are easy to replace.

Again are you hearing that relay click on the fuse IP panel, on top on the left hand side. If you have the two shot relay, is all solid state and is quiet, but still can be tested individually.

On confusion exists between the brake and tail lights, your brake lights are working?

On with the parking lamps as they are call, Cruze has ten of them and all in parallel. Two in the front head lamp assemblies, four markers on the side of the car, and four in the rear. If the fronts are working, this says the head lamp switch, it sends a command to the BCM, but this is where I get lost as to whether a relay is used or not, owners manual is not accurate in this respect. But we know if the front are working, can only be one wire running back to the six parking lamps.

I have yet determined whether the Cruze is using insulation displacement terminals or not, but was an age old problem with these. Instead of stripping the ends of wire and crimping the terminal around it, pierces the insulation just making a very poor point contact. 

Invented some new cuss words when I first ran into this.


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## NickD (Dec 10, 2011)

Ha, reminds me of my son-in-laws dad, regardless of the problem, least according to him, its always the computer. 

In reality, not much different than your home computer getting that blue screen for one example. Vast majority of the problems are software related, least at home, you can reload windows, rare to find a hardware problem. Recently in my own smart phone, had all kinds of crazy problems, but was in the flashram chip.

If you have tried to design analog circuits in the past depending on what is called a sample and hold circuit, would go crazy, operation depends upon maintaining a charge on a capacitor for an indefinite period of time. Slightest bit of leakage current destroys these circuits. Flashram had zillions of these capactive memory circuits and expected to hold an extremely small charge for a period of at least ten years to tell the difference between a logical one or zero.

Would think a reflash would be the first step before blaming the BDM, All vehicles have been using this weak approach since 1996, crazy, but thanks to EPA laws, can't reflash at home. Never bothered carrying towing insurance before they started this pure nonsense, have been ever since. Only a 0.75 V spike on the wrong pin can reset all this firmware, and you already know how your home computer works before you load the OS. You get nothing. 

Makes me wish I was not an electronic engineer when driving on an isolated road in subzero weather knowing all this stuff, would be far better if I had blind faith. Don't bother writing to your congressman on these issues, they also have blind faith.


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## 7STW (Mar 30, 2011)

Jim:

Not to threadjack this post, but do you (or others) have any recommendations on the specific "extended" warranty you would buy? And from what source etc?


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## Robby (Mar 1, 2013)

7STW said:


> Jim:
> 
> Not to threadjack this post, but do you (or others) have any recommendations on the specific "extended" warranty you would buy? And from what source etc?


I would only recommend factory backed plans....GMPP (G.M. Protection Plan) for G.M. vehicles.

Trouble is, I don't think purchass is allowed beyond the base warranty period.
That info must come from a finance manager or G.M.P.P. itself.

Careful though.....many dealers sell aftermarket agreements claiming they are just as good as the G.M. plan.
THEY ARE NOT!!!! They are more profitable for the dealer and far more problematic for the buyer.....stay away.

Good luck!
Rob


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## NickD (Dec 10, 2011)

With no access to firmware replacement or updates, they have us exactly where they want us. By the proverbial balls. And using retarded flashram to store this most important data your vehicle depends upon to run.

We no longer own our vehicles, but just a license to use them. Have to pay dearly for this license, either up front or by some maintenance agreement. Like any insurance company, have to charge at least 30% more to stay in business.

And my wife wonders why I wanted to purchase a pre OBD I boat and motorhome. Independence I told her, what America is suppose to be all about. Supra does have PROMs, can live with that, for awhile, plus all the diagnostic systems for the five computer systems are all built in, don't even need a $5,600 scanner to read this data.

Just making us more and more dependent, I don't like this.


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## Jim Frye (Mar 16, 2011)

Robby said:


> I would only recommend factory backed plans....GMPP (G.M. Protection Plan) for G.M. vehicles.
> 
> Trouble is, I don't think purchass is allowed beyond the base warranty period.
> That info must come from a finance manager or G.M.P.P. itself.
> ...


I agree. Also, there are many different options to extended warranties. Make sure you have the one that meets your needs. Also, be mindful of the deductable (if any). The reason I finally caved was the cost of some of the electronics in the car. The Nav. system in my car is a $2,500 part cost plus labor. The ECU is also expensive. I didn't price any other components, but for the extra $1,000 for an additional 5 years of B2B coverage with $100 deductible, I thought I'd take the gamble.

As an example, we bought a new refrigerator (one of those big French door models) a couple of years ago and spent $99 for the extended warranty. We had three service calls on it at $100 per call when the manufacturer decided it was no-repairable. Warranty company gave us $1,600 in store credit for a new fridge. Should be so lucky with a car warranty.


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## ingrambr (Apr 25, 2013)

I'm having the exact same problems as described in this e-mail and I wanted to know what you did in the end?

I have a 2010 Cruze and the tail lights, brake lights (except for the central one in the upper rear windscreen) and trunk have stopped working. I took it to a dealer where they told me electricity was getting to the BCM, but nothing was coming out. Based on that, they said I need to replace the BCM. $1200 for the part and then $400 to install it and reprogram it.

I live in Chile, so things maybe more expensive here, but that is a ridiculous amount of money.

I have some questions:
1) Is it possible that the BCM might be okay but just need reprogramming?
2) Earlier in the thread, someone mentioned the soldering was pretty poor, is it really worth exploring this? Can anybody point me to circuit information for the BCM found in the trunk?

Any help or advice would be greatly appreciated.


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## ChevyGuy (Dec 13, 2014)

ingrambr said:


> I have a 2010 Cruze and the tail lights, brake lights (except for the central one in the upper rear windscreen) and trunk have stopped working. I took it to a dealer where they told me electricity was getting to the BCM, but nothing was coming out. Based on that, they said I need to replace the BCM.


Seems like an odd combination. I suspect that the cable either shorted out or became unplugged. I'd try another repair shop. I think there is a good chance the dealer's tech is misinterpreting something.


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## ingrambr (Apr 25, 2013)

So just an update, the battery seems to have died definitively and now nothing is working except for something cranking under the hood.

Should I go back to the dealer and see if it's just the battery that was playing up all along? Are they likely to admit this? Here it's just turned cold for autumn, so it probably fits right?


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## peligro911 (Apr 8, 2015)

ingrambr said:


> So just an update, the battery seems to have died definitively and now nothing is working except for something cranking under the hood.
> 
> Should I go back to the dealer and see if it's just the battery that was playing up all along? Are they likely to admit this? Here it's just turned cold for autumn, so it probably fits right?


If possible have the battery tested .. if bad then replace see if your other problem go away.. 
battery tent to go out in when hot or cold.. i have had two battery go bad shortly after some brutal heat in the summer time.


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## peligro911 (Apr 8, 2015)

bksmm said:


> My dealership let me know the bad news. He said both the BCM and the trunk latch need to be replaced. The tech thinks the BCM went bad which caused the trunk latch to go bad. The BCM will be 468 + tax and the trunk latch 169 + tax.
> 
> By the way, the taillights and the trunk latch are the only things not working on the car. Nothing happened that we know of that caused them to go bad and I have never done any modifications to the car. My cruze is a 2011 with 55,000 mile on it. I won't buy another car that relies solely on electronics to open the trunk.


Is is still under warranty ? I hope so .. when i got my cruze i thought it was strange how the truck had no release from inside the car and is all electronic. Hope they get it fixed for you


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## Virus_invader (Jul 28, 2018)

Did anyone find the solution? I have the same problem.


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## Blasirl (Mar 31, 2015)

Virus_invader said:


> Did anyone find the solution? I have the same problem.



Welcome Aboard!:welcome:

The OP's solution

*Special Coverage #14311: Negative Battery Cable

New Rear Trunk Lock Release Switch With Licence Plate Lamp For Chevrolet Cruze New Buick Regal 2009-2015*

European Cruze Repair Manual


Don't forget to introduce yourself here.


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## Blasirl (Mar 31, 2015)

Acquire one of these: 12V Ni-CD Rechargeable Battery 













A few of these: Female Disconnects









some red and black wire









a couple of alligator clips









and a cheap meter from Harbor Freight (for some reason the picture will not load - but is a free coupon)

and you will have a great duo of troubleshooting tools

You could add one of these for a nice trio:


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## Virus_invader (Jul 28, 2018)

I need the solution from someone yhat had the same problem. Please?


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## Virus_invader (Jul 28, 2018)

I found the solution. I fixed my BCM for 250 euro. Now everything is ok!


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## Maggierobbins (Feb 14, 2020)

bksmm said:


> A few days ago, we discovered that the trunk on our 2011 Cruze LS would not open with either the key button or the rear trunk latch. The doors were unlocked and the keys were not in the ignition but it would not open by either method.
> 
> Today, someone stopped my wife to tell her the brake lights weren't working. So here are the result from my investigations. I am using terms from my owner's manual to avoid confusion.
> 
> ...





bksmm said:


> A few days ago, we discovered that the trunk on our 2011 Cruze LS would not open with either the key button or the rear trunk latch. The doors were unlocked and the keys were not in the ignition but it would not open by either method.
> 
> Today, someone stopped my wife to tell her the brake lights weren't working. So here are the result from my investigations. I am using terms from my owner's manual to avoid confusion.
> 
> ...


Hi did u find wat the problem was? I have same problem now


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## Liverpool (Oct 1, 2020)

bksmm said:


> A few days ago, we discovered that the trunk on our 2011 Cruze LS would not open with either the key button or the rear trunk latch. The doors were unlocked and the keys were not in the ignition but it would not open by either method.
> 
> Today, someone stopped my wife to tell her the brake lights weren't working. So here are the result from my investigations. I am using terms from my owner's manual to avoid confusion.
> 
> ...


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## Liverpool (Oct 1, 2020)

Hi 
My name is Carlos from South Africa and have the same problem did they found the problem and what was the problem because our dealer ship is quite expensive please help?


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## NitroCharger (Jan 21, 2021)

Maybe the problem is with ground connection number g309.

Service Information

http://chevrolet.chiptune43.com/graphic-pool/2/20/5/2205910.png


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## Bray35 (Jul 30, 2021)

bksmm said:


> A few days ago, we discovered that the trunk on our 2011 Cruze LS would not open with either the key button or the rear trunk latch. The doors were unlocked and the keys were not in the ignition but it would not open by either method.
> 
> Today, someone stopped my wife to tell her the brake lights weren't working. So here are the result from my investigations. I am using terms from my owner's manual to avoid confusion.
> 
> ...


Did u ever figure out what it was haven same problem on my 2011


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