# Potential water leak in trunk



## Blasirl (Mar 31, 2015)

_Condition_On certain 2016-2017 model year Chevrolet Cruze vehicles, the center high mount stop lamp (CHMSL) fasteners may back off over time and cause a water leak, allowing water to flow into the rear compartment battery tub. When the battery tub fills with water to a height of 50mm or more, the DC/DC converter module board and connector are exposed to water which may cause corrosion. If water drains below the DC/DC converter, a resistive short may occur on the printed circuit board which could result in an unattended fire when the DC/DC converter is powered.
_Correction_Dealers are to inspect for water damage in the battery tub electrical components, and replace the CHSML gaskets and nuts (adding Loctite to the nut).


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## Iamantman (Sep 24, 2018)

Oh **** that's kind of bad. If you're under warranty I would think that trunk panel needs to be repaired and then replaced. If they won't though and you want to try to clean it I'd try some vinegar and a soft toothbrush. Wear a mask though cuz you don't wanna breath that stuff in.


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## mumbogray (Feb 6, 2019)

Blasirl said:


> _Condition_On certain 2016-2017 model year Chevrolet Cruze vehicles, the center high mount stop lamp (CHMSL) fasteners may back off over time and cause a water leak, allowing water to flow into the rear compartment battery tub. When the battery tub fills with water to a height of 50mm or more, the DC/DC converter module board and connector are exposed to water which may cause corrosion. If water drains below the DC/DC converter, a resistive short may occur on the printed circuit board which could result in an unattended fire when the DC/DC converter is powered._Correction_Dealers are to inspect for water damage in the battery tub electrical components, and replace the CHSML gaskets and nuts (adding Loctite to the nut).


Thank you. I wasn't expecting that the mold on the trunk hood liner would be caused by water in the battery compartment... but I took a look after work, and there is indeed a pool of water! I noticed it in the wheel well. My battery seemed dry; I couldn't find any water in that well. I have a weathertek trunk liner, so maybe that diverted it.

It is a red flag that you mention the CHMSL. I had a crack in mine, posted pics in a different thread. It was replaced only a few weeks ago. The dealer charged me for the repair out of warranty. I contacted Chevy Care and tried to get it replaced under warranty for Bulletin No. 16-NA-308. At the time I told them I was worried about water leaking, but I did not ask them to check the trunk, and I don't know if they did. I can't say for sure if the water started accumulating before or after the service, as I only recently noticed because of the mold.

Should I contact the same dealer that replaced the CHMSL and ask them to fix this? I was hoping to visit a different dealer, but I don't want to have to pay for this again.


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## Blasirl (Mar 31, 2015)

When was the last time you opened your trunk prior to finding the mold? I would at least go to the dealer to document it.


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## mumbogray (Feb 6, 2019)

I found the mold on Wed 6/12. I last used the trunk 4 days earlier on 6/8, and everything looked normal then. The brake light assembly was replaced on 4/22. I bought the car Jan 11th.

At the time the brake light assembly was replaced, I don't know if the proper steps to seal the piece were taken. I mentioned the TSB, but they stated my car didn't fall into that program.

When I visit the dealer this time, how should I go about asking them to perform the repair under the TSB? I saw the full details on gm.oemdtc.com, but the TSB is now removed due to a cease and desist. Any advice on where I should sign up to get a full list of TSB's for the Cruze?


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## jblackburn (Apr 14, 2012)

The brake light is the most common; it should be a RECALL listed for the car. As is the battery tub drain. This usually ends up with water in the battery compartment; if you see it elsewhere in the trunk, it's probably not the brake light.

Some Gen 2's have also had water leaks at spoiler bolts, and some around the right taillight. The dealer should have a body guy in-house or someone they contract out to check the car for leaks.


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## mumbogray (Feb 6, 2019)

Just to follow up as I finally got the full repair documents:

The tech stated the seal for both the left and right tail lamps was worn. They replaced the backup lamp assembly on both sides, Parts 84075816 and 84075815. They also replaced my liner 84114303 and gave me new clips 1605396.

Prior to replacing the CHMSL in April, and prior to my ownership of the car, the tech said the water leak recall was performed (any way to see if they installed the drain? for peace of mind). This is in line with above recommendations, as there was no water in the battery tub; only the wheel well. The recent CHMSL repair seems to be truly coincidence after all.


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## Robert75 (Dec 22, 2019)

I have a 2018 premier RS sedan, I had water coming down in that same spot and pooling in the spare tire well. It seems that dealerships are hit and miss with repairing these leaks, so I fixed it myself. Mine was leaking at the far left and right of the spoiler. There is a plastic pin on the spoiler that snaps down into the trunk lid on both sides. That is where mine was leaking. I removed the spoiler put sealant around those pins and all the studs, remounted the spoiler, and the leak is gone. I would keep a eye out for more water in your trunk, I had to remove the light housings out of the trunk lid to access the spoiler studs and nuts. I don't see how those light housing gaskets would just start leaking. Good luck!


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## Blasirl (Mar 31, 2015)

Robert75 said:


> I have a 2018 premier RS sedan, I had water coming down in that same spot and pooling in the spare tire well. It seems that dealerships are hit and miss with repairing these leaks, so I fixed it myself. Mine was leaking at the far left and right of the spoiler. There is a plastic pin on the spoiler that snaps down into the trunk lid on both sides. That is where mine was leaking. I removed the spoiler put sealant around those pins and all the studs, remounted the spoiler, and the leak is gone. I would keep a eye out for more water in your trunk, I had to remove the light housings out of the trunk lid to access the spoiler studs and nuts. I don't see how those light housing gaskets would just start leaking. Good luck!


Welcome Aboard!

Any chance you took pictures while you did your repair? If so, consider writing up a How-To on fixing them.
How-To: Write a Tutorial

Don't forget to introduce yourself and your Cruze here.


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## Robert75 (Dec 22, 2019)

Sorry, I didn't think about taking any pictures. I was trying to beat a two day rainstorm, and hadn't joined this forum yet. Anything of importance that I do in the future will be documented and shared here. We need to work together as a team and help each other out.


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## Stvnhi (Aug 26, 2020)

Mold on the top trunk liner is coming from the seal that the trunk closes on.
I've had this same issue before.
As you can see in the pictures it was a rainy day when I noticed it.

Took a couple more today of it cleaned up and also where the water was pooling (between the plastic and the rubber seal)


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## jblackburn (Apr 14, 2012)

Stvnhi said:


> Mold on the top trunk liner is coming from the seal that the trunk closes on.
> I've had this same issue before.
> As you can see in the pictures it was a rainy day when I noticed it.
> 
> ...


If this is a RS trim with a spoiler on the trunk lid, that's also exactly where the tabs on the end of the spoiler leak down onto the taillights.


















How-To: Fix Trunk Spoiler leaks on Gen 2 sedan


If you have a Gen 2 sedan and have a water leak in the trunk after rain, it's likely one of two things: 1. The third brake light - there's a recall for 2016/17's to replace the gasket. Sometimes after the gasket is replaced, the third brake light assembly itself will crack. This water usually...




www.cruzetalk.com


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## Stvnhi (Aug 26, 2020)

Oh man I missed one of the posts explaining this, My fault.
Yes this is the 2017 RS package. 
Thank You mentioning that.
Is there an easy way of getting to the underside to check that?
Is it just pop the tabs on the trunk liner?


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## jblackburn (Apr 14, 2012)

Stvnhi said:


> Oh man I missed one of the posts explaining this, My fault.
> Yes this is the 2017 RS package.
> Thank You mentioning that.
> Is there an easy way of getting to the underside to check that?
> Is it just pop the tabs on the trunk liner?


To see where it was coming from, I took the trunk liner off, wet down the trunk lid, and stuck a camera phone through one of the trusses in the inner trunk lid.

I saw it dripping off the taillight, so thought it was the taillight seal leaking, but once the camera phone was in there, it was clear as day that it was actually coming from that rivet, then running down the taillight.


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## Stvnhi (Aug 26, 2020)

Nice. Thank you I’ll look into this myself. Much appreciated for the correction btw lol


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## jblackburn (Apr 14, 2012)

Stvnhi said:


> Nice. Thank you I’ll look into this myself. Much appreciated for the correction btw lol


Good luck! Mine unfortunately happened out of warranty, so it took me a couple weeks to figure out where the heck it was leaking from. It was an easy DIY fix, though.


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## paul26 (Sep 6, 2020)

jblackburn said:


> If this is a RS trim with a spoiler on the trunk lid, that's also exactly where the tabs on the end of the spoiler leak down onto the taillights.
> 
> 
> 
> ...


Is this how it looks like when you removed the spoiler? I have a 2017 LT with RS package and I have the same water leak issue. I have been to dealers more than 3 times and they replaced right taillight but it still leaks


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## jblackburn (Apr 14, 2012)

paul26 said:


> Is this how it looks like when you removed the spoiler? I have a 2017 LT with RS package and I have the same water leak issue. I have been to dealers more than 3 times and they replaced right taillight but it still leaks


Yep those tabs are right above each taillight. They will drip down directly on the taillight housing and make it appear the seal is leaking.


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## paul26 (Sep 6, 2020)

jblackburn said:


> Yep those tabs are right above each taillight. They will drip down directly on the taillight housing and make it appear the seal is leaking.


Thanks a lot! I tried to seal the spoiler around the outside, as I didn't want to go over the troubles of removing light housing. I'm not sure if that'll work lol


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## jblackburn (Apr 14, 2012)

paul26 said:


> Thanks a lot! I tried to seal the spoiler around the outside, as I didn't want to go over the troubles of removing light housing. I'm not sure if that'll work lol


Super easy to remove, just a foam gasket that will reseal if you clean up around the light. 

The tabs themselves need a blob of silicone applied around to stop the dripping. Mine sits on an incline with the trunk facing down in the driveway, so water just pools behind the lip of the spoiler when it rains.


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## paul26 (Sep 6, 2020)

jblackburn said:


> Super easy to remove, just a foam gasket that will reseal if you clean up around the light.
> 
> The tabs themselves need a blob of silicone applied around to stop the dripping. Mine sits on an incline with the trunk facing down in the driveway, so water just pools behind the lip of the spoiler when it rains.


Thanks! Would you mind telling me what tools I need? I'm in another state and about to head out to buy tools first. I got silicone seals in my car, and just wondering what kind of screwdrivers I need


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## jblackburn (Apr 14, 2012)

paul26 said:


> Thanks! Would you mind telling me what tools I need? I'm in another state and about to head out to buy tools first. I got silicone seals in my car, and just wondering what kind of screwdrivers I need











How-To: Fix Trunk Spoiler leaks on Gen 2 sedan


If you have a Gen 2 sedan and have a water leak in the trunk after rain, it's likely one of two things: 1. The third brake light - there's a recall for 2016/17's to replace the gasket. Sometimes after the gasket is replaced, the third brake light assembly itself will crack. This water usually...




www.cruzetalk.com





A 10mm, an extension, a swivel joint, and a trim puller tool for the rivets on the trunk got me to all of them.


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## paul26 (Sep 6, 2020)

jblackburn said:


> How-To: Fix Trunk Spoiler leaks on Gen 2 sedan
> 
> 
> If you have a Gen 2 sedan and have a water leak in the trunk after rain, it's likely one of two things: 1. The third brake light - there's a recall for 2016/17's to replace the gasket. Sometimes after the gasket is replaced, the third brake light assembly itself will crack. This water usually...
> ...


This is super helpful. Thanks! 
Just curious, if it's caused by the leaky spoiler, the water doesn't go to battery compartment and thus wouldn't damage the battery / electronic units, right?


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## jblackburn (Apr 14, 2012)

paul26 said:


> This is super helpful. Thanks!
> Just curious, if it's caused by the leaky spoiler, the water doesn't go to battery compartment and thus wouldn't damage the battery / electronic units, right?


Generally, spoiler = spare tire area, 3rd brake light = battery compartment.


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