Diode mod caused MyLink system to stop working - void warranty

jlchavezz1 · May 6, 2015

Hello all. I write this because I recently had my MyLink system stop working along with the speakers and light display on the steering wheel. This happens randomly one day. I was driving with the music on and the screen froze and the music stopped. When I reached my destination I turned the truck on and off and this time the screen worked no more. At night there is backlight illuminating the screen but the screen itself does not work. The only function it works in is the reverse camera. I was finally able to take it to the dealership and they are telling me the "resistors" (that's what they called them instead of diodes) is what caused the problem and now I am liable for the charges to get it fixed. Has anyone with this mod (low beam to fog lights) had any complications with their truck? Thank you very much for the responses.

I own a 2014 Silverado LTZ

newdude · May 6, 2015

Can't speak on the mod but, if they can prove that those are the cause of the MyLink issue, I can see it being on you. That is if they removed or bypassed them, and then the truck stopped acting up. Either that or they are using them as an excuse. But, IF they can prove it...

jlchavezz1 · May 6, 2015

Thank you for your response.

Dangerdick · May 6, 2015

Sounds like you either did the mod wrong or they're trying to mess with you

darkfox1 · May 6, 2015

What does a microvoltage pulling in a relay for headlights have to do with a radio?

Seems like the bcm would be burned out from overvoltage if anything.

A new bcm is less than $150.

Repgramming it.. well that might be $200 or more but still..

When you say "mylink" are you talking about the radio? or the dash screen? You mentioned reverse camera so I imagine you're talking about the radio, in which case it could be the hmi unit. I assume the hmi and bcm talk somehow to communicate the in dash info with the in radio info.

I fail to see what a diode jumped from headlight to foglight has to do with the radio. I also fail to see what the bcm has to do with the hmi unit functioning BECAUSE of foglights.

I'd say they have a pretty steep hill to climb to prove this is the case.

My question is this though. how did they know you had the "Resistors" to begin with?

Dunc · May 6, 2015

Sounds like you either did the mod wrong or they're trying to mess with you

This. The diode mod is on a completely different circuit from the radio. So assuming your diode was in the right spot then they are trying to blame it on the diode to get out of it.

jeff_94 · May 6, 2015

I'd like to know more myself because I had done this on my 07 Silverado with no problems and wanted to do the same on my 2015

jlchavezz1 · May 6, 2015

I've had this mod on for about 8 months without a problem. It has always worked correctly. My problem with the 8" touchscreen didn't happen till 2 weeks ago. The in dash screen works fine it's the 8" screen that doesn't work except when you put the truck in reverse then you do get an image. As soon as you put it in drive or park the screen goes blank. Also the speakers don't work at all. When I put the blinker on I get no sound. They have been working on the truck since 7:30am (central time) without any success. They don't know what's the problem therefore they shouldn't know what caused it.

As for how they found out I had the so called "resistors" I guess they just looked around for any aftermarket parts.

SLESierra · May 6, 2015

Check out this from February

http://sandyblogs.com/techlink/?p=4246

SLESierra · May 6, 2015

Also not PI1375A also covers 14 models as well it was just PI1375 the A was added in Feb of this year

http://vitalysmobileautodiagnostics.com/6368/blank-display-nav-screen-audio-content-is-unavailable-via-speech-recognition-display-screen-is-stuck-on-incoming-call-view-after-phone-call-finished-rear-view-camera-display-blank-usb-issuesbluet

jlchavezz1 · May 6, 2015

Update: After a whole day at the dealership the service representative calls and let's me know the "resistors" are not causing the problem. They also said they tried a different radio which didn't fix the problem. They will hold off the truck until tomorrow because they haven't been able to fix it. They mentioned they contacted GM and tomorrow morning an engineer will contact them with how to proceed. I'm glad they dropped the issue with voiding warranty but disappointed I will be another day without my truck. The service representative said if another day would go by without success they would put me in a rental vehicle.

newdude · May 6, 2015

Good to hear. It appears they were quick to pull the trigger on you for sure. Hopefully they get to the bottom of it. A good bit of diagnostic tools to test the radio/interface systems on these trucks so hopefully they fix it.

pancepance · May 6, 2015

You are lucky my friend.
The bottom of the driver seat heat function stopped working on mine. Passenger side worked completely and driver side only the back of the seat worked for heat.
My dealer told me the issue was due to the aftermarket lights I have. I argued the point and was basically told to pound salt. I took to another dealer and they didn't even look at the problem. Apparently somehow it was noted on the network and as such they called me within a few minutes after dropping it off to tell me the problem was due to aftermarket lighting and would not be repairable under warranty. I know they didn't even look cause there wasn't enough time to do so literally.
F'in a'holes. I'm gonna have someone fix it myself cause I'll be dammed if I'm gonna pay a dealership to do it so they make money off of me.

Sorry just venting but true story. I've had pretty much all my service issues voided due to "aftermarket" something. Guess that's the price I have to pay to have the truck how I like it. I knew the risk when I did it but never knew how crazy it would be. My tundra was lifted and had aftermarket HID's. Never once did the dealer pull the "voided warranty" card on me. They fixed everything and anything without question. That is primary reason that when an actual new tundra comes out I'll give this thing away to get one. Till then I'll just keep fixing things on my dime.

darkfox1 · May 7, 2015

OBVIOUSLY your heated seat failure was because you had aftermarket gasoline in your gas tank.

Seriously tho this varies a lot by dealership. I've had 2 run ins with a dealership down the road from me, not wanting to sell me parts, not wanting to discuss mods without mentioning the warranty..

I'm glad this dealer dropped it on the diodes. If you had an issue where your cargo light wouldn't work.. or would never turn off, or something like that.. I'd totally understand them pointing to the modified pinouts for that, but.. for the radio? nope.

It would be like me as an IT guy saying that your computer got a virus because you changed the color of your aero theme in windows 7.

adam.busch · June 14, 2016

So this started when I got a Left Rear Turn Indicator Failure on the DIC and the dome light overhead switch not working or dome lights coming in with the door open. I took the truck in today and got it diagnosed. The diode mod, performed exactly like the steps in this forum, somehow shorted out my BCM. I can't believe that would have done it, considering several other things that BCM controls work without issue. Well, new BCM and programming repair will cost one $675 dollars, all because I forgot to take out the damn diode before going to the dealership. Hard life lessons.

sidenote: I also performed the footwell lights modification and I'm certain this somehow factored into the equation.

You think my fog light mod truely causes my issue?