alright, I believe its firmware then. But my brother in law goes to classes every year to keep up, has worked on pretty much everything and knows so much off the top of his head.

I think its assiniene for that complicated of a charging system. Holy crap, what happened to an alternator with regulator set 14 volts? That how our 2 boats are set, and our 2 tractors (one from 60's other 80's) and guess what, THEY WORK FINE!!! We can throw cheap batteries in our boats let them sit over winter un-charged and they will last longer than a good battery in our suburban. Had my P3 hooked up driving today, stayed a strong 15.2 volts, shut the key off, drops to 12.0 volts!! I shut off the lights and anything else I can and watch it come up to a measly 12.4 volts, then after 5 min something FINALLY shuts off allowing the battery to recover to 12.7 volts and ever so slowly creep the 12.7X up almost to 12.80...

This is overcomplicated bull ****. I have to get his fixed or else Im out a $160 battery with in a year

 

They claimed it improved mpg but I'm calling BS on that.

There shouldn't be a charge to upgrade to software it hasn't been done.

If you do have to replace the alternator, I'd stick w/ AC/Delco like in2pro suggested.

 

I do think that the correct software extends battery life based on my experience. My 2007 failed in less than three years and my current battery made it past four years and still seems strong. Never had an OEM battery make it much past the warranty before.

 

Thanks very much for posting. Very helpful.

 

My third full test drive about 367 miles today with 6 start ups. Voltage gauge did not go below 14 volts.
Longest run time between start up was just under 3 hours.
Test parameters with headlights on low and a/c on (front and rear)
headlights only (at night with only a very ever so slight dimming of headlights when cooling fans turned on and voltage gauge did not go below 14 volts.
daytime running lights only

Test 1 and 2 with generic scan tool monitoring BCM voltage between 14.4 and 14.6 volts with same test parameters above, only in town driving for 13 miles with total engine running at 58 minutes between start up.

I installed a new current sensor on the charging cable between the alternator and mega fuse block. I left the original current sensor on the negative battery cable because I said to myself with I upgraded the negative battery cable that I will break the sensor if I have to remove it due to the size of the 3 wires going thru the sensor.

Note the current sensor is directional on the negative battery cable, it senses current flowing from the battery to the engine block. So use a permanent marker to draw an arrow showing current flow so you will install it in the correct direction on the charging cable. Also note that my suburban was purchased used and had a generic top post battery terminal on the negative cable, making mine easier to remove if I had to. Install the current sensor on the charging cable pointing away (your newly painted arrow on the current sensor before you removed it) from the alternator.

I drive a 2009 Chevrolet Suburban LTZ with 5.3L with active fuel management and during test drive the active fuel management did engage to just 4 cylinders and back to 8 under demand.

So basically the BCM thinks the battery is discharging by sensing current on the charging output wire from the alternator, thus is keeps the voltage at or very near to 14.6 volts

Usually at idle with headlights on at night is was annoyed me the most with a significant dimming of the headlights and the voltage gauge going way below 14 volts .... this is what I am trying to resolve and so far ..... a success for me.

FYI, my BCM generates a 10 volt source to the current sensor, apparently there is also a 5 volt model. Should not affect either way just make sure current sensor is pointing the the correct direction. I am responsible for my own vehicle modifications only.


old sensor on the left, new sensor on the right