It Rained so 2015 Yukon won’t start, Help!

[MD-Wood]

I'd start with a good cleaning of all of your ground points in and near the engine bay and BCM. After that, I would suspect the BCM or at least its connections. The WD40 on the BCM main connector is a good idea to try. Given that the behavior is different when using the key fob, I would trace the wiring from the start button to the fuse block and BCM as well.

Re crimp your battery cable ends. Hot/ cold dry and humid all have effects on these ends and that year had connector issues.

 

[Hitman]

As always whenever we get wet weather our 2015 Yukon won’t start. The dash goes funky, all the warning lights, multiple service issues on screen like
-service airbag
-service trailer brake
-service steering column lock
-service front camera (doesn’t even have one)

Sometimes dash will go black like dead battery, won’t roll over at all then dash will go funky. Weirdest of all it will start off factory remote start on fob. I managed to get the scan tool on it and this is everything it gave me

Service steering column lock
Service airbag
Service front camera


C0110-61 pump motor circuit - stuck
Erased and all went away

U0140-00 lost comm with bcm
U0155-00 lost comm with IPC
U0170-00 lost comm with pass presence module

Erased and all went away


B2575-04 headlamps control circuit open

B2645-07 ambient light sensor high voltage

B2699-04 right headlamp circuit open

B305A-00 no response from steering column lock received

B3111-00 keyless entry transmitter 3 battery

B3935-00 transponder authentication

B3979-00 no environment identified received from hvac module

C0755-29 right front pressure sensor to few pulses

C0750-29 left front tire pressure sensor to few pulses

C0760-29 left rear

C0765-29 right rear

U0078-00 control module communication low speed CAN bus off

U0164-00 lost comm with HVAC module

U0208-00 lost comm with seat memory

U0236-00 lost comm with steering control module

Erased and all gone but

B305A-00 & B3111-00



U0029-00 MOST bus performance

Erased and went away



U0078-00

U0151-00 lost comm with inflatable restraint sensing and diagnostic module

U0155-00

U0184-00 lost comm with radio

U0198-00 lost comm with telematic control module

U0230-00 lost comm with liftgate control module



Erased all went away except

U0184-00 & U0230-00 stayed

This has been a major pain in the hole, I’ve seen many other write ups with similar problems but I’m yet to come across a fix, has anyone managed to find a fix to this extremely frustrating problem. Any help would be appreciated, doing everything I can to avoid a trip to hells gate (local dealership).

Thanks

In my 2015 yukon XL I had a similar issue water was some how getting into the truck, the passenger floorboards always wet. I tried everything to find the leak, cleaned sunroof drains, etc, looked at AC coil nothing, taped up some holes in the fender by hinges, sealed around the battery area, so on.

In all of this I pulled off the passenger door sill and trim then lifted the carpet, in the floor rail there is a wiring harness and connector. It was full of water.

I never had anything short out but always on my mind when it would happen.

Maybe this might help your situation.