Spendit

You did nothing to the 3rd tranny either? Man that is some miles on the thing, here in Michigan they are way rusted out by then

Have you replaced the negative cable yet - there was crimping issues on these OE cables. I changed mine out and problem solved

They are only powered up at key on.....

Contact pgamboa - he made harnesses for many on this site

I have a 2014, but at 6 years old I had similar issue - ended up buying new harness for that side, all corroded up from exposure to tire "fling/crud/debris" attacking connection terminals and getting to pins.

It is not a sunroof vehicle - the dampness on the headliner is above the 3rd brake light level....but I will start there

The truck was simply parked in driveway and headliner is soaking wet. Its only the rear cab portion and this is above the window and break light line.....maybe a crack somewhere in cab top? I noticed some water line marks from a previous soak but did not catch it when wet....anyone find something as strange as this

Just turned 115+K miles of which I put on 95+K. New battery and ground wire to block (bad crimp on OE), repaired a frayed 02 sensor wire and new right rear tail light harness (corroded). Regular oil changes and new brakes, plugs & wires recently. Only real issue's are: rusted out frame and lower cab panels, leak in rear cab headliner area and of course its white so the paint is flaking off in the typical areas. Overall a reliable truck for this Michigan climate.

I replaced my batt negative to the engine - did my own crimp to larger lug there and cleaned up the small end to frame. Been in good shape for 4 years now... you should all healed

I went through something similar last year - found a wire out of the loom had rubbed on the frame, needed to splice in a section and cover back up.

Ive replaced with 2nd new sensor - this one a GM OE part, did the heater relearn and still permanent codes. I can clear them and drive but immediately return at next key cycle. Leading me to believe there is a broken wire somewhere, as the voltage does not change like B2S2. I believe the white wires are the heater circuit - anyone know pin out for these O2's? Both CAT temps are same through drive cycle, so I think its fine.....

GMC 2014, 5.3L, 103K miles - truck set code for bank 1, sensor 2 (downstream), the replacement sensor works after clearing code but continues to return code for HO2S heater performance. Code comes up with each key on cycle, if I clear at idle the code returns after short drive. Once I clear code again I can drive for hours without code however, various heater commands don't change (%, mA) and both low voltage test and open status test "malfunction". Could the new sensor be bad out of the box or does the module not like this manufacture type (NTK 21075), everyone was out of DENSO? Anyone have similar situation and solution?

I fixed my '14 by replacing ground from battery to engine & frame - bad crimps are also known issue on these

In all my 30+ years of doing shade tree mechanic brake jobs, I have never put the assembly line hold-in-place bolts back on. Rotors on 1st and a move down the line to caliper install required them to keep things in place. If they are a recommended item most repair kits would include them as well.......I say they are not needed

Spurshot - Curious if the pan drop was as bad as some report - wedging up engine, small hands to twist it out between cross member and all the wood chunks and straps to have on hand? I have the 5.3 CC with 100K now

I traced my issue back to bad crimp on the negative battery cable, terminal itself - new from Rockauto fixed it, going on 3 years now

Huge thread with all your answers inside the modification area - do a search for PGAMBOA

I traced my 2014 to a bad crimp on the negative cable itself (battery end). I replaced it with new and all god for over 2 years now.

Following - same spot on my 2014, white in color and spot continues to peel away with time.

AND - how is the ride improvement? I have the same tires and need to replace shocks on my '14

Anyone know if the latch bezel will just pop out from the outside, or a trick to get the tailgate open? Trying to get at the rods to release the latch, tannuae cover is latched down too. Don't want to rip if off and loose the backup camera as well -

Went thru similar in a 2014 Sierra - ended up replacing the actual ground from battery to engine and cab wire. Original crimps on OE cable bad....getting the block connector off was a PITA, only cost some blood

Right side of my 2014 - took a new harness to solve the issue. Lots of debris gets thrown onto the connectors under the light housings.....was ~$60.00 from Rock Auto

Just replaced one on my 2014, someone tagged me at a boat launch......was tough to find OEM and it was $280 from Rockauto

2014, DC 6'5 bed, 5.3L, 6 speed - at 78K now. Became 2nd owner at 29K, 3 years ago.......runs and drives like a long cab, 4x4 pickup with very little mods from original. No: oil burn, fluid leaks, H2O intrusion, electrical gremlins (blank screen, rear slider blowouts, PS drop out, lamps going dark) or NVH issues beyond whats expected. Only fluid change to date has been oil at 6K since i've owned it and nothing reported by leasing dealer from previous owner or GMC records. New: Battery spring '19, new 20" KO2's 6 months after I bought it (Michigan winters), putting in LED backup lights this weekend (921 Dieselleds), pads changed due to boat hauls (surge brakes), wipers (again winter beats things up around here), headlight bulb, rear taillight harness (right side). Truck sits outside everyday and night, get a quick bath after a few hunts or salt builds up, has been driven fully loaded from South Dakota to Pennsylvania, added full floor mats to sweep out mud and folding soft tannue cover. Hope I get 1/2 the life out of it from the '94 Sierra I gave up with some 300K on it (not waxed one time :))