No crank no click no start after driving just fine. Potentially related to fuse 35 / DLIS in 2011 Yukon

[Bardgm]

Posting this half as an ask for the wisdom of this group, and half to maybe help someone else out in the future, at least temporarily.

Started up my 2011 Yukon today here in Canada, a nice warm -6c or so (About 20f) and drove 15 minutes into town to drop some things off while the truck sat for about 15 minutes. Jump in it to start and go get some groceries, and nothing. No click, no crank, just the check engine light on the dashboard. Weird. It doesn't get driven a lot now, and I've had to boost it once this winter in some very cold spells, and it's turned over hard a few times. But today it started fine to leave home, and then nothing in town. Thought it might be the neutral safety selector, but the dash lights matched the shifter selection. Giggling the shifter, key, shifting gears, all that jazz didn't fix it.

I tried boosting just to be sure, to no help. At this time I took stock, and everything else seemed to work. Blower fan, lights, locks, windows, which seems different than many of the posts here where everything dies at once.

Hit up the YouTube while I waited for a buddy to come along with some electric grease and sockets to try and unplug the BCM connectors under the hood per this video, since that video claimed to fix the exact problem I had. I tried swapping some of the under hood fuse box relays around just in case that was it but also nothing. Just as I was getting ready to give up, I found this video from South Main Auto which has the same symptoms. Now in this video, the culprit is a corroded and non-functional fuse 35 (Labeled as DLIS). Once SMA replaces that fuse things seem to work for him. I pulled mine out and fortunately (unfortunately?) it looked fine. Replaced it, and then my buddy pulled in. Went to show him how the truck wouldn't start... and it started right up. Convenient.

Obviously not going to drive it to anywhere other than my place with it potentially going to leave me stranded, so hooked up the battery charger to it to top it off so I can test a few things tomorrow on it. But it seems like that DLIS fuse is related to the issue I'm having. Here is what I tested tonight after driving the truck home.

Touch nothing
Try and start truck
Truck starts fine
Turn off
Pull DLIS fuse
Security light is on in dash
Try to start with fuse out
Does not start
Leave key in run or acc I think?
Replace fuse
Try and start
Security light still on
Won't start
Turn key to off / remove
Try and start
Started fine

Going to try a few other combinations tomorrow to see if I can narrow down this ghost in the wires before buying a new code reader or taking it to the shop. I do have some spare fuses of that size (2a) but so far it's been working with the same fuse it started with. The wildest part of this to me is that it just started working either randomly or after re-seating a fuse.

So hopefully this is helpful to someone else who's truck tries to leave them stranded in the cold, and if anyone has ideas of the root cause or other troubleshooting steps please share!

 

[Doubeleive]

I think you may be over complicating it.
1st test the battery (load test),
check the battery cables be sure they are clean even if they look ok. (they can corrode inside and look fine outside) you can do a load test on these as well.
check the starter, starter cables on these can get burnt and go bad, there is a relay in the fuse box you can pull it and jumper the starter on if it engages then it's likely not the cables.
check the shift interlock and neutral safety switch.
check the ignition
be sure the security light is not lit constant
keep it simple, if all that passes then proceed to troubleshooting other more random issue's, this fuse thing is not very common never even heard of it before although it is a good idea to check your fuses as well to rule it out.

 

[Joseph Garcia]

^^x2^^ for logical and orderly diagnostics of most likely causes.

My '97 had a similar issue, in that this condition popped up randomly. It turned out that the ignition switch was failing intermittently, and then it failed completely.

 

[Bardgm]

Thanks for the advice so far, always good to have a reminder to check the obvious stuff first. I'm just so flabergasted that it "magically" started working yesterday after pulling that fuse. I'll start working through the steps suggested to see if anything looks wrong there, but it is starting now.

 

[Fless]

Are these the fuseboxes that get corroded underneath where the fuses go?

 

[denalianyone]

Check ground wires..I don’t think the issue was related to that fuse. The truck sitting for a little while triggered something that may have been corroded or loose. The DLIS is the ignition switch and theft deterrent module.

 

[Doubeleive]

in that video the fuse box has been exposed to the weather, lid was off for a long time or the lid was off and hood was open for a while, normally they do not look like that inside at all. So normally that fuse should not be a issue, that was a good diagnosis using the scan tool. The security light being on would have took me down another rabbit hole though.

 

[Bardgm]

Update. Followed the advice given here and went to the basics. Confirmed that everything on the ignition switch side was good and the starter relay was working and closing when I put the key in crank. Tried to get into the starter to get some voltage readings, but between it being up against a wall and a nice new layer of undercoating oil I had a hard time getting a reading. Jumped the starter relay and still no turnover.

Gave the starter a few taps of encouragement and it started for me once more. Made the genius move to turn it off while I called the mechanic and lowered the jack and it wouldn't start again no matter how many taps I gave. Anyway, towed it down and they confirmed the starter was bad. New one in now and she works like a charm.

So seemingly just blind luck that it re-started the first time after messing with that fuse.

Thanks for the guidance all! Glad to have her running again.

 

[Geotrash]

Thanks for following up with your resolution! Glad it's working for you now.