Wont start "Chassis control module"

Bash74 · February 27, 2020

Bash74 · February 27, 2020

This may or may not be related as there are so many ways a system can fail but the comment about a failure to communicate with the chassis control module is/was part of my issue. I've had a serious problem lately with my 2016 Silverado dying on me but it usually throws up a bunch errors starting with Service Trailer Brake and Stabilitrac Off, before going into limp along mode and then eventually just packing it in, though the engine continues to run but the tack drops to zero. Once I shut it off it will not re-start however at one point when it wouldn't start I disconnected the EBCM (ABS) and it started. I reconnected it and it wouldn't start (suggesting the issue was the EBCM or the CCM or the wiring in between). There is also a clear correlation between this happening and wet sloppy Ontario roads. Twice I've had it towed to a dealer and what they've found is a slew of communication errors between all of the devices on the main GMLAN which includes the ECM, TCM, TCCM, Telematics module, HMI module, Body Control Module, PSCM, EBCM and finally the Chassis Control Module. Unfortunately however by the time they've taken it into the shop, it runs and there are no active faults. Two dealers spent a combined 14 hours pulling apart wiring harnesses starting where they go through the door sill all the way to the chassis control module and found nothing. They said it's almost always a small nick in the wire with signs of corrosion around it. Eventually I got tired of paying big bucks for someone to unwrap wires so I took it home and started pulling it apart myself and checking the wires inch by inch very carefully. Eventually in a section just in front of the left rear wheel I found what is almost certainly the culprit, exactly as described. The nick was in an area that neither dealer had touched I suspect because it's such a pain to get at. In my case the wire wrapping had loosened up and the wrappings had filled with mud and salty water but I suspect subsequently drained out upon sitting allowing the communications to resume. Appreciate that the network operates between 1 and 3 volts so pulling it down doesn't take much. As of this morning I have it all back together and no fault codes. Fingers crossed that I've fixed it. It's just started snowing so tomorrow will be a good day for a test drive.

Corrosion is what was wrong with mine and trailer brake. Had chassis com fault U1556 and it had a service bulletin, which the trailer brake module / plug may have moisture intrusion & need replacing. Module was replaced and no problems since.

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swathdiver · February 27, 2020

On 2/25/2020 at 2:12 PM, Bmcghan09 said:

I just bought a 2014 Sierra 1500 Z71 double cab with 95.000 miles. Saturday I went to get my hair cut and after got in my truck to leave. It wouldn't start. I keep a scan tool on me so I scanned it and no codes. Everything would turn on and work just no signal to the starter. I call onstar for towing and I'm sitting there randomly trying to start it. Putting it in neutral, cycling the locks all the old tricks. I open the hood, check the cables and everything is fine. Go to start it and boom started right up. I drive right to the only dealer who's open and they determined it was the license plate LED lights and they should be normal lights. Dealer tells me that's all and sends me on my way. I go to start it to leave and once again it wont start. They scan it again and determine the chassis control module was not communicating for some unknown reason. I leave it there and all day yesterday and today its been starting just fine. So I guess I am going to pick it up tonight. I don't like the idea of rolling the dice every time I go to start my truck.

Anyone experience this or have an idea? Dealer is clueless.

Bad cell in the battery from my experience. How old is it? What is its state of charge after sitting overnight?

Bmcghan09 · February 27, 2020

8 hours ago, swathdiver said:

Bad cell in the battery from my experience. How old is it? What is its state of charge after sitting overnight?

I really doubt its a bad battery. The battery looks brand new and there's no other issues. 9* outside and started fine. This truck is CLEAN crazy clean frame too. No rust anywhere. This spring I'll spend a day pulling the harness and checking for peace of mind.

BlaineBug · February 27, 2020

Being that this Silverado is a 2014 and falls within the range of the issues with the G218 ground, you might want to have the dealership perform TSB 18-NA-161 if it is under warranty.

According to the TSB, G218 with the insulation issue was an issue for trucks built prior to June of 2015.

Bmcghan09 · February 27, 2020

7 minutes ago, BlaineBug said:

Being that this Silverado is a 2014 and falls within the range of the issues with the G218 ground, you might want to have the dealership perform TSB 18-NA-161 if it is under warranty.

According to the TSB, G218 with the insulation issue was an issue for trucks built prior to June of 2015.

1GTV2UEH7EZ100315 I think its AUG. but I will look into this!!

BlaineBug · February 27, 2020

If your truck is a 2014 model year then it was most likely built towards the end of 2013 through mid 2014, right? I'm thinking a truck built in June of 2015 would be a 2015 model year. You can always confirm the build date with the sticker at the B pillar, if you have it.

You can also investigate G218 yourself as there are plenty of write-ups and video tutorials to go along with it. Would take you maybe 30 minutes to an hour versus the whole dealership waiting game shenanigans.

Edited February 27, 2020 by BlaineBug

BlaineBug · February 27, 2020

This pertains to 2017 model year Silverado and Sierra but is worth a look.

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

Edited February 27, 2020 by BlaineBug

swathdiver · February 27, 2020

3 hours ago, Bmcghan09 said:

I really doubt its a bad battery. The battery looks brand new and there's no other issues. 9* outside and started fine. This truck is CLEAN crazy clean frame too. No rust anywhere. This spring I'll spend a day pulling the harness and checking for peace of mind.

You cannot see a bad cell from the outside of the battery. I'm on these forums every day and more often than not random trouble codes and blinking lights are due to bad batteries, not grounds or cables though those ought to be checked too.

BlaineBug · February 27, 2020

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 the battery out and brought it in for them to test on their counter without being connected to anything in the vehicle.

Perhaps the OP should do the same just to clear the noise.

In my experience, a failing, weak, or dead battery will result in weak starter motors and a huge lack of electronics power to the vehicle. Not a vehicle that starts normally 99% of the time.

Edited February 27, 2020 by BlaineBug

tbarn · February 27, 2020

Put a starter in it.

Bmcghan09 · February 27, 2020

13 minutes ago, tbarn said:

Put a starter in it.

Probably should put a transmission too huh?

tbarn · February 27, 2020

Let me see, you have a 6 year old truck, 100k miles, turn the key on and everything seems fine. Turn it further to start position and it does not crank. Nah, couldn't be the starter. Must be an led bulb or a bcm or fuel pump/ chassis control module or battery cables or a wire buried deep in a harness somewhere God knows where. Do ya think maybe you're overthinking it a little bit?

Bmcghan09 · February 27, 2020

10 minutes ago, tbarn said:

Let me see, you have a 6 year old truck, 100k miles, turn the key on and everything seems fine. Turn it further to start position and it does not crank. Nah, couldn't be the starter. Must be an led bulb or a bcm or fuel pump/ chassis control module or battery cables or a wire buried deep in a harness somewhere God knows where. Do ya think maybe you're overthinking it a little bit?

Actually starter is fine. The command to start never made it to the starter... We could see and even I could see that. The dealer could see that the start command was not sent to the starter. It ended at the BCM due to a fault............ My post states signal was not getting to the starter as well..

Edited February 27, 2020 by Bmcghan09

Bmcghan09 · March 7, 2020

Update: I think I have it narrowed down to a short in the license plate circuit. Just happened to me again last night and wouldn’t start for about 12 hours. I have a super super nice scan tool with me now and it read short to battery license plate. I think that is what back fed and shut down the CCM. Because they are all right there. Going to pull the harness down soon.