2014 Silverado electrical nightmare

carnau · March 3, 2020

22 hours ago, Johnbellaville said:

Positive and negative cables have been replaced not the issue

Yeah, I wasn't saying you have issues personally. I was saying the battery cables have issues on these trucks. Sorry if that was confusing. I still need all the codes and I can help you with this. I can also give you information that the other dealer could be overlooking if you give me the codes.

Johnbellaville · March 3, 2020

26 minutes ago, carnau said:

Yeah, I wasn't saying you have issues personally. I was saying the battery cables have issues on these trucks. Sorry if that was confusing. I still need all the codes and I can help you with this. I can also give you information that the other dealer could be overlooking if you give me the codes.

Ok just got it back still not fixed here goes with the codes u0073 u0102 u0101 u0121 u0140 u0401 p0575 p0700 p0856 p1506 p2544 u0415 u0100

carnau · March 4, 2020

43 minutes ago, Johnbellaville said:

Ok just got it back still not fixed here goes with the codes u0073 u0102 u0101 u0121 u0140 u0401 p0575 p0700 p0856 p1506 p2544 u0415 u0100

Ok, I am going to do some research on these codes and follow them down a high speed circuit and see where the problem is more than likely. Is the vehicle working fine at the moment or is it failing currently?

carnau · March 4, 2020

47 minutes ago, Johnbellaville said:

Ok just got it back still not fixed here goes with the codes u0073 u0102 u0101 u0121 u0140 u0401 p0575 p0700 p0856 p1506 p2544 u0415 u0100

Did they give you the printout I asked for? The reason I ask is I need to know which module is setting the codes. For instance, the ECM is setting the u0073 and the BCM is setting the U0102.

Johnbellaville · March 4, 2020

6 minutes ago, carnau said:

Did they give you the printout I asked for? The reason I ask is I need to know which module is setting the codes. For instance, the ECM is setting the u0073 and the BCM is setting the U0102.

Johnbellaville · March 4, 2020

12 minutes ago, carnau said:

Ok, I am going to do some research on these codes and follow them down a high speed circuit and see where the problem is more than likely. Is the vehicle working fine at the moment or is it failing currently?

Truck is running fine now but that will change lol

carnau · March 4, 2020

6 minutes ago, Johnbellaville said:

Truck is running fine now but that will change lol

I need the VIN number for the truck so I can get the RPO code list please.

Johnbellaville · March 4, 2020

16 minutes ago, Johnbellaville said:

Truck is running fine now but that will change lol

kwOH · March 4, 2020

All grounds checked and cleaned took to dealer and they replaced positive and negative cables 450$ still having the same issue 1000$ this month no luck

What about the battery harness or the wire that goes to the fuse box?

carnau · March 4, 2020

Ok. So this is why I really needed you to get the print Report from GDS2. Its not your fault, They should have just printed it out for you instead of making you right it all down. The reason I say that is it shows the EBCM with code u0121 which is no communication with the EBCM. The EBCM can not give itself that code. Another thing is I am missing some key module codes. In the schematic I have below you have a TCIM (onstar module) HMIC (radio module) and Power steering control module all on the system without any codes in them. This is impossible. You have a EBCM that can't communicate with the BCM,TCCM,TCM and the TCCM that can't communicate with anything yet you have no codes in the TCCM or the PSCM? That means the system has to make some wiring jumps that are impossible unless this vehicle creates its own wiring as you drive. Next they wrote, or told you to write. No communication with the chassis control module or the park brake module. Well the reason for this is, your vehicle RPO's tell you that you don't have JL1 (chassic control module) and trucks come with a manual parking brake... so you don't need a parking brake control module... So your truck doesn't have these modules, that's why they are not communicating.

I hope you didn't pay them anything. This is actually making me upset they didn't take the time to give you the proper information because they are either 1.) Lazy 2.) don't want to tell you they have no idea what they are doing. or 3.) Don't care enough about you to help you. This is why dealerships get a bad name.

With that said. With the information you have given me. I have a question. When everything goes crazy in the truck, does it cut off?

I will explain.

It looks to me that you have an intermittent wiring failure between the ECM X1 39 and 40 to TCM X1 10 and 11.

That or you have a bad ECM.

If the truck does not shut off when this happens that lets me know the ECM is still working, it just cannot communicate with past the break. If you would check across terminals 6 and 14 at the DLC when the problem happens. You would probably find that you have 120ohms of resistance instead of the 60ohms you need. This would be because of the break in the system and only reaching 1 terminating resistor. If you look at the document there is a 120ohm resistor in the ECM and a terminating 120 past the EBCM. If the whole system is working you will have 60ohms. If it's at 120ohms you disconnect the ECM and check again. If it has 120ohms still you start bypassing modules on the way to the ECM also back testing the 120ohm resistor across each module you disconnect.

I know this looks like a whole bunch of jibberish. I understand it 100% because I do this everyday but I can see how it would look like Japanese. If you don't understand something I have said please please please ask and i will do my best to explain it further.

Your next step should be to get a printout from GDS2 of the DTC report even if you have to go to a different dealer.. If i can get that I can get you pretty close if not 100% completely accurate of where the break is or narrow it down to 2 modules and a pair of wiring that will be easy for someone to check.

Or you could just get the dealership to unpin, solder and replace the 2 terminals at the ECM and TCM and run new wiring. This is what I would do if it were my vehicle. I don't know that I would let the dealership you took it to do it... But that's again up to you.

Johnbellaville · March 4, 2020

My handwriting is way better than that lol that is what they gave me and they wouldn’t let me have my truck until the bill was paid but no truck has never shut off on me I did cut it off to reset the limp mode one time and it wouldn’t crank back up for like 2 minutes. I gave them a terrible review they probably wouldn’t give me anything now will probably trade this thing in soon

Edited March 4, 2020 by Johnbellaville

carnau · March 4, 2020

1 hour ago, Johnbellaville said:

Truck is running fine now but that will change lol

Here is a scan of the High Speed System from the picture. Gives you a better idea of what I was trying to explain.

carnau · March 4, 2020

5 minutes ago, Johnbellaville said:

My handwriting is way better than that lol that is what they gave me and they wouldn’t let me have my truck until the bill was paid but no truck has never shut off on me I did cut it off to reset the limp mode one time and it wouldn’t crank back up for like 2 minutes. I gave them a terrible review they probably wouldn’t give me anything now will probably trade this thing in soon

I hate that cause this is literally an easy fix. I know it sounds in depth, but $20 worth of wiring, $20 worth of terminals and you're fixed. Is it a big dealership? This is something that needs to be fixed at a dealership, just not that dealership. Are there any other dealerships close to you? Take a trip to SC, I'll fix it for you. lol

Timmer66 · March 4, 2020

My Silverado had a very similar issue. Lots of faults, reduced power and eventual death. And also when the weather was wet/snowy and crappy. Then after sitting would miraculously self fix. Turned out to be a corroded network wire just in front of the rear wheel. When it got wet it grounded the network and nothing could communicate. A bit of solder and some heat shrink solved it. To the credit of the dealership I dealt with, they really worked to dissuade me from replacing the EBCM when I thought it was the issue, saying they had yet to see one fail. So I persevered until I fount the nick in the insulation.

Johnbellaville · March 4, 2020

11 hours ago, carnau said:

I hate that cause this is literally an easy fix. I know it sounds in depth, but $20 worth of wiring, $20 worth of terminals and you're fixed. Is it a big dealership? This is something that needs to be fixed at a dealership, just not that dealership. Are there any other dealerships close to you? Take a trip to SC, I'll fix it for you. lol

I appreciate your efforts on this it does give me hope I’m going to a shop I was referred to today to see what they say