2017 LED Turn Signal Randomly Doesn't Work

Sierra17 · November 20, 2019

I have a 2017 SIerra SLT that is out of factory warranty. It has the factory LED headlight/turn signal modules. The drivers side front turn randomly will not work. Sometimes it won't flash on lock/unlock from the remote, other times after I start the truck it won't flash. The rear drivers side and mirror led's do flash, just not the front. If I shut the truck off and start it up again that will normally fix it for a while. I swapped the headlight control module between sides and that didn't help. I haven't been able to reproduce the issue enough to test swapping the entire headlight modules between sides. Any thoughts on what it might be or other things I could try?

JimCost2014 · November 20, 2019

22 minutes ago, Sierra17 said:

I have a 2017 SIerra SLT that is out of factory warranty. It has the factory LED headlight/turn signal modules. The drivers side front turn randomly will not work. Sometimes it won't flash on lock/unlock from the remote, other times after I start the truck it won't flash. The rear drivers side and mirror led's do flash, just not the front. If I shut the truck off and start it up again that will normally fix it for a while. I swapped the headlight control module between sides and that didn't help. I haven't been able to reproduce the issue enough to test swapping the entire headlight modules between sides. Any thoughts on what it might be or other things I could try?

Welcome to the site.

If you are still on your original battery, have it checked, or replace it

The new generation trucks do all kind of weird things when the battery starts to fail.

Sierra17 · November 21, 2019

On 11/19/2019 at 9:56 PM, JimCost2014 said:

Welcome to the site.

If you are still on your original battery, have it checked, or replace it

The new generation trucks do all kind of weird things when the battery starts to fail.

Thanks for the suggestion! I had the battery tested today and it was BAD! I put a new battery in and so far the turn signal has been working, but it will take a few days to know for sure. Crazy that may have been it! I can't believe it was just affecting the signal on one corner.

Edited November 21, 2019 by Sierra17

JimCost2014 · November 21, 2019

13 hours ago, Sierra17 said:

Thanks for the suggestion! I had the battery tested today and it was BAD! I put a new battery in and so far the turn signal has been working, but it will take a few days to know for sure. Crazy that may have been it! I can't believe it was just affecting the signal on one corner.

You are very welcome.

I agree, it is weird, but on the positive side, it gives you signs that it is going to fail, rather than just stranding you in the middle of nowhere.

tpilews · November 5, 2021

Any update on this? My 2017 started doing this last December when we were visiting Ohio. It hadn't done it all spring/summer and most of fall since then (we live in Florida). Just noticed this happening again randomly now that the weather has cooled down.

Edited November 5, 2021 by tpilews

tpilews · March 19, 2022

Just wanted to add more information to anyone looking with this same issue. I ended up replacing the battery, issue when up getting worse within 2-3 weeks of the new battery. The turn signal works about 20% of the time.

tpilews · March 24, 2022

Another update... Dealership is replacing the fuse box. Said there was a bunch of water and corrosion in it. I'll get it back in a week and will provide another update.

erschmidt · December 8, 2022

On 3/24/2022 at 2:35 PM, tpilews said:

Another update... Dealership is replacing the fuse box. Said there was a bunch of water and corrosion in it. I'll get it back in a week and will provide another update.

Did this fix the issue? I have the exact same symptoms.

GMCustomerService · December 12, 2022

On 12/7/2022 at 8:38 PM, erschmidt said:

Did this fix the issue? I have the exact same symptoms.

This is certainly not what we like to hear, erschmidt. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your truck. To do so, please send an email to [email protected] with ATTN: erschmidt/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s Privacy Policy, please visit https://www.gm.com/privacy-statement.html. The information you provide may be monitored and recorded and is subject to the GM Privacy Statement.

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mikeyk101 · December 13, 2022

@GMCustomerService can you kindly explain how this post provides any kind of resolution so others can know how to fix their problem? The point of this forum is to provide help with solutions to fix problems. I have yet to see any of your posts do that

Brenty D · April 27, 2023

I have a 2016 Sierra with the exact same issue and have had the issue since new.

It works good 95% of the time. I told the dealer about it when it was new but it never acted up when i was at the dealer so they did nothing about it. The only way i have found that resolves the issue temporarily is to turn off the truck, wait for all accessory lights to turn off than restart the truck and it always works after that. seems like its usually first thing in the morning when starting it and i had a new battery installed not that long ago but its almost like when the vehicle charges up the battery ever so little it works better. I'm assuming its a sticky relay that needs optimal volts to operate correctly.

tblentrprz · November 8, 2023

Working on a 2015 Yukon with RR LED turn signal (RPO X88) no op. No output from BCM to RR LED turn signal. No problem with LR. Inputs from turn signal and Hazard switches to BCM are good. Continuity from BCM X4-4 to RR LED turn signal BN terminal is good. OK BCM failed - replace. Programmed and performed setup using GM SPS2 software on BCM. Still no BCM output to RR turn signal. Confirmed still no BCM turn signal output to RR. What am I missing? BTW - new AGM battery installed 2 weeks ago.

Edited November 8, 2023 by tblentrprz

tblentrprz · November 8, 2023

FIXED!!! 8 fuses feed the BCM. BCM fuse 6 (15A) bad. Interesting - no codes stored. No other circuits/function inop. Glad this is done. FYI - some good info from SD.

Sierra17 · November 16, 2023

My issue did come back again after replacing the battery. It ended up being the entire headlight module! Such a disappointment, there was no way to replace just the turn signal portion. It is fully integrated into the module. I knew it wasn't the control module as I had swapped that from the other side. I finally replaced the entire module. It was the most expensive turn signal repair cost I've ever had.

2017L83 · November 17, 2023

I have this same issue now with my '17 sierra 1500. I had it before then it went away and is now back again with the cooler weather. I don't get how it could be the whole module if it just works perfectly some times. One would think if the LED was bad it would stop working for good. I haven't been able to find any differences in battery voltage when it is or isn't working, there is always power right up to the plug and I've swapped the control modules from one to the other before with no difference. Could a bad ground after the signal possibly cause this? Ive checked the one under the rad with no success. I can't believe they would make an entire headlight module that can't be serviced and want their customers to pay $1200 for a signal light .