What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Doubeleive]

I had the tech2 hooked up yesterday and under body/bcm there is a electrical section, in there is option to command the regulator from 40-90%, no matter what I commanded it didn't make any difference and with the fans on high speed it was discharging the battery at around -7/8/9 amps, just doesn't seem right, had the same results swapping battery's & alternators

so I did a little web crawling and have found there is a software update for the charging system for my VIN most of the bcm software is current except the charging system and personalization, so I will probably take it to the dealer on Monday or maybe today and have them flash the bcm, I could probably do it from home but I don't feel like bricking my bcm at least if they do it it's on them.

 

[Rocket Man]

Wth? I was just sayin... jeez. I have a billion black ones if you want me to mail some to you.

A bazillion black left nuts?

 

[iamdub]

Hopefully someone can help me out with something that just came up... whenever I floor it, everything will cut out very briefly at around 5k. Gauges all drop to 0 for a split second and it lights up like a Christmas tree and says stabilitrack off. Anyone have a clue?

VTEC kicking in.

 

[iamdub]

Hopefully someone can help me out with something that just came up... whenever I floor it, everything will cut out very briefly at around 5k. Gauges all drop to 0 for a split second and it lights up like a Christmas tree and says stabilitrack off. Anyone have a clue?

My first stab at this is a voltage regulator issue. Shift to a lower gear that gets the RPM up but lower than the problem area. Accelerate and see if it happens at a specific RPM. Watch your voltage gauge or, better yet, measure it at a power port ("cigarette lighter" socket).

 

[HiHoeSilver]

A bazillion black left nuts?

Only a billion.

 

[Rocket Man]

Only a billion.

Oh...well that makes sense then.

 

[PG01]

Hopefully someone can help me out with something that just came up... whenever I floor it, everything will cut out very briefly at around 5k. Gauges all drop to 0 for a split second and it lights up like a Christmas tree and says stabilitrack off. Anyone have a clue?

Stop flooring it ..........just sayin

 

[kbuskill]

I had the tech2 hooked up yesterday and under body/bcm there is a electrical section, in there is option to command the regulator from 40-90%, no matter what I commanded it didn't make any difference and with the fans on high speed it was discharging the battery at around -7/8/9 amps, just doesn't seem right, had the same results swapping battery's & alternators

I know this may be a dumb question but how are all you battery cables and grounds???

 

[Rocket Man]

Stop flooring it ..........just sayin

Can’t be done.

 

[Doubeleive]

I know this may be a dumb question but how are all you battery cables and grounds???

New ground cable with sensor in the last 6 month, both battery's are less than 2yrs old (odyssey extreme agm's 34/78), big 3 upgrade, plus a new nbs style positive cable direct from alternator to 2nd battery, I do loose about .2 amps from alternator to battery I get like 13.78 testing alternator direct to ground bracket, then I get 13.58 at either battery

when I was testing it yesterday I (think) it was showing fuel economy mode-active when the voltage was down to 11.3v, which it should not have been active as far as I can gather which is making me lean towards a firmware issue. There is a bit of technicality to how the rvc system works like how much battery charge it shows, what the battery temp is estimated at etc, etc.