Help, 2011 tahoe 4wd PPV main brake lights not working.

[dksupraman]

Help!
This will be a long post to inform of all the diagnosis and repairs already done.

I have a 2011 Tahoe 5.3 4wd
Issue: Main brake lights won't turn on with pedal. Third brake light works properly. All other exterior and interior lights work properly.

This vehicle had a long list of issue when diagnosis first started for the main brake lights not turning on. When it first showed up, the passenger reverse light and sometimes the 3rd brake light would stay on with the vehicle turned off and would drain both batteries overnight. Also, The rear hatch won't open.

Problems found & Repairs made:

-Multiple codes of all kinds in almost every module. No communication to fpcm w/Jl1
-Driver door harness had multiple broken wires in the pass thru. (repaired)
-All exterior bulbs burnt (all exterior bulbs replaced)
-Damage to Brake switch signal wire at brake switch (repaired, Brake switch confirmed working properly)
-Faulty battery signal sensor (replaced)
-Faults internal to BCM (replaced w/ New Dormain Unit & properly programmed from gm) side note: before BCM programming, brake lights worked, but both reverse lights stayed on. After Programming All PPV functions added to BCM, main brake lights quite working.
-Found PCM adding .235v to brake signal wire. Light blue/white wire. (replaced and programmed)
-both rear light harnesses had severe corrosion (replaced both rear light harnesses)
-Faults internal to ABS module (replaced)
-Replaced Fuel pump control module with JL1 option (trailer brake controller) (have full communication with module now)
-Replaced Engine Bay Fuse Block Assembly.
-Inspected All fuses in engine bay and driver side interior fuse block.
-Inspected entire chassis harness, passenger compartment harness under driver dash to rear hatch (all damage/corrosion found was repaired)

All Modules receive the signal to command the brake lights, the BCM will not turn on the left and right outputs for the brake lights.
All Other Exterior and Interior lights work Properly.
Question:
What am I missing???
Is There a jumper wire somewhere to put the vehicle in stealth mode and disable the brake lights?

 

[mikez71]

Should not be the 'surveillance' mode.

Looks like a L-BU wire at J6-2 on the BCM? Goes to UBEC (underhood fuse block) where it splits to the two stop lights. If no ouput on that wire.. maybe new BCM is bad?

 

[dksupraman]

Should not be the 'surveillance' mode.

Looks like a L-BU wire at J6-2 on the BCM? Goes to UBEC (underhood fuse block) where it splits to the two stop lights. If no ouput on that wire.. maybe new BCM is bad?

a new one will be here friday. and I have some emails out to gm to see if theres something in the coding.

 

[metal man]

Any fix for this? Same issue 2011 Yukon xl 2500, former fire dept vehicle, everything works but left and right brake lights. Traced all wires to the main fuse panel, chmsl (center high Mount stop light) works, no blown fuses, but fuse diagram also doesn't seem to correlate to half the circuits. Emergency lights (whelen) didn't seem to tie into vehicle lights. Even tried messing with parking brake, no change.