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Wont start "Chassis control module"

Bmcghan09

By Bmcghan09
in Troubleshooting & Recalls

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BlaineBug Enthusiast

BlaineBug

Posted
Posted (edited)

Where is this ground located?  I know there should be two main grounds coming from the battery.  Haven't traced either of them yet.

Edited by BlaineBug
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Bmcghan09
Bmcghan09

Probably should put a transmission too huh?

Bash74
Bash74

So what did the dealer say it wasnt communicating too. For instance, I had a no communication fault (U1556) but it was for the trailer brake module not communicating. This didnt stop the truck from be

BlaineBug
BlaineBug

The same thing was suggested to me about a bad battery and just go ahead and replace it anyway.  I had it checked three times by three separate auto parts stores, and on the third try I actually took

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Bmcghan09 Enthusiast

Bmcghan09

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This ground is in the passenger side wheel well. You do not need to remove the fender liner to get to it. I used a wire wheel and adhesive remover. I cleaned it up pretty well when I was done. But you can see that something may have been going on with the ground itself. The other runs to the back of the engine block and looked fine. I may do what someone else did and add another ground to to brake booster. I have not pulled the dash apart yet for the BCM ground. That will be my next step. 

BlaineBug Enthusiast

BlaineBug

Posted
Posted
4 minutes ago, Bmcghan09 said:

This ground is in the passenger side wheel well. You do not need to remove the fender liner to get to it. I used a wire wheel and adhesive remover. I cleaned it up pretty well when I was done. But you can see that something may have been going on with the ground itself. The other runs to the back of the engine block and looked fine. I may do what someone else did and add another ground to to brake booster. I have not pulled the dash apart yet for the BCM ground. That will be my next step. 

That sounds like G141.  Tech found mine to be "full of undercoating" the other day as well.

Bmcghan09 Enthusiast

Bmcghan09

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6 hours ago, BlaineBug said:

That sounds like G141.  Tech found mine to be "full of undercoating" the other day as well.

I'll pull the dash one G218 this week or weekend. looks to be like a 10 minute job to get to it. 

BlaineBug Enthusiast

BlaineBug

Posted
Posted (edited)

"A ground bolt without the proper hardening may not properly clamp/secure the ground eyelet."

What would improper hardening do?  Does this cause the fastener to stretch over time?

I have also heard G141 referenced many times for being corroded or in my case it was undercoated.  How badly it was undercoated, I don't know since I didn't do the work.  Apparently G141 is the only connection between chassis and the battery as G103 is between the battery and engine.

Edited by BlaineBug
Bmcghan09 Enthusiast

Bmcghan09

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6 minutes ago, BlaineBug said:

"A ground bolt without the proper hardening may not properly clamp/secure the ground eyelet."

What would improper hardening do?  Does this cause the fastener to stretch over time?

I have also heard G141 referenced many times for being corroded or in my case it was undercoated.  How badly it was undercoated, I don't know since I didn't do the work.  Apparently G141 is the only connection between chassis and the battery as G103 is between the battery and engine.

Yes from the battery it is only two grounds, one to the frame and one to the engine. Engine looked to be fine. G141 on mine was pretty nasty. I bet only half the terminal was contacting. Lots of undercoat under it and some corrosion.  I tightened it up pretty good. It's still on my list to add a ground from the battery over to the break booster. This would put a direct BCM ground less than 12" from the battery ground. I assume the bad fastener does stretch and allows the terminal to back away. 

Bmcghan09 Enthusiast

Bmcghan09

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Just now, BlaineBug said:

Has your issue returned after checking out G141?

I wont know, It happened a couple times like 5 weeks ago on a Saturday dealer had it for a few days couldn't make it do it again and then 4 weeks later it did it and wouldn't start for like 15 hours. Tried it once in the morning then one more time an hour later and its been fine since. It hasn't done it to me since friday night, I had it towed home because I knew it would start. I just cleaned up the ground tuesday and I guess we wont know for a while. 

Bmcghan09 Enthusiast

Bmcghan09

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20 hours ago, BlaineBug said:

Just about as sporadic and elusive as you can get.  That's unfortunate.

Well taking the dash apart was very fast and easy less than 5 minutes. Now getting to the ground is another story it’s in an awful spot and but I finally got to it. And yup the plastic was pinched right there. I had to use a shallow well 10mm a universal and a few extensions but I got it off and trimmed. I’m just realizing I forgot to put a harness clip back on that ground but oh well. 

88C995C8-044F-4DFE-BA75-556536B75B01.jpeg

A43AA81E-4C13-439F-B3D4-2E52667461AE.jpeg

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BlaineBug Enthusiast

BlaineBug

Posted
Posted (edited)

Seeing that your truck is a 2014 model I would have thought your dealer would have taken a look at all of the TSBs.  And the TSB regarding this ground G218 is definitely on par for 2014-2015 models for sure.

What's the harness clip that you forgot?

TSB 18-NA-161.pdf

Edited by BlaineBug
Bmcghan09 Enthusiast

Bmcghan09

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1 hour ago, BlaineBug said:

Seeing that your truck is a 2014 model I would have thought your dealer would have taken a look at all of the TSBs.  And the TSB regarding this ground G218 is definitely on par for 2014-2015 models for sure.

What's the harness clip that you forgot?

TSB 18-NA-161.pdf 2.32 MB · 3 downloads

It is just a little plastic piece that runs a harness over the ground. I’m sure it’ll be fine. Probably just for assembly/ rubbing reasons. 

BlaineBug Enthusiast

BlaineBug

Posted
Posted (edited)

I think I know what you're talking about.  My OCD would probably have me re-doing it.  By the way there is apparently also a ground under the same location on the passenger side.  Although the BCM doesn't ground there so it hasn't been problematic as far as I know.

Edited by BlaineBug

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