Wont start "Chassis control module"

BlaineBug · March 11, 2020

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 March 11, 2020 by BlaineBug

Bmcghan09 · March 11, 2020

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 · March 11, 2020

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 · March 11, 2020

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 · March 13, 2020

https://static.nhtsa.gov/odi/tsbs/2017/MC-10113871-9999.pdf

Take a read here. Some good information. Pertains to grounds having faulty bolts that loosen up I believe?

Bmcghan09 · March 13, 2020

This is a good read!

BlaineBug · March 13, 2020

"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 March 13, 2020 by BlaineBug

Bmcghan09 · March 13, 2020

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.

BlaineBug · March 13, 2020

Has your issue returned after checking out G141?

Bmcghan09 · March 13, 2020

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.

BlaineBug · March 13, 2020

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

Bmcghan09 · March 14, 2020

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.

BlaineBug · March 14, 2020

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 March 14, 2020 by BlaineBug

Bmcghan09 · March 14, 2020

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 · March 14, 2020

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 March 14, 2020 by BlaineBug