Engine grounds

[jetmech]

I'm having an electrical problem which I am almost positive is a ground issue. If I am not mistaken, 4 grounds attach to the block - (1) large gauge wire (looks like 4 or 2 AWG) which attaches to the block underneath the number 1 and 3 cylinders, (2) smaller gauge wires (18ish AWG) which attach to the rear of the block, and (1) flat braided ground wire which attaches to the back of the block to the body. Is that correct? or did I miss a ground?

Issues I am having are:
1 - truck takes throttle and accelerates, but intermittently stumbles and picks back up (a feeling you'd experience if you were in the throttle, suddenly lifted off and went back in)
2 - Dash is saying "battery not charging" despite the multimeter reading over 14 volts at the battery when the engine is running, over 12 volts when the truck is not running, and the truck cranks over without hesitation
3 - The "battery not charging" message comes and goes every few seconds, and the battery light illuminates when the "battery not charging" message is displayed

The alternator is brand new, and this truck is an '06 Silverado (DBW....unfortunately). Please help!

[farmtruc]

Sounds like you checked all the grounds.
I've seen an intermittent open in the harness cause this before.

any dtc's in history?

[jetmech]

any dtc's in history?

P0054 - H02S Heater resistance (bank 1 sensor 2)
P0060 - H02S Heater resistance (bank 2 sensor 2)
P0102 - Mass or volume air flow circuit low input
P0103 - Mass or volume air flow circuit high input
P0622 - Generator field/F control circuit
P1637 - Manufacturing specific DTC No information available at this time
C0035 - DTC not recognized
C0040 - DTC not recognized
C0055 - DTC not recognized
C0245 - DTC not recognized

The guy i took it to claims he wrote a speed density tune for it. That said, I am confused as to why the PCM is throwing MAF codes. Also, I am only using the upstream 02 sensors, so the heater resistance codes should not be showing up either.

[farmtruc]

The rear o2 codes can be removed.

The 622 and 1637 can be turned off if the alternator and battery are working correctly.

C codes aren't engine codes.

I'll take a look at the next sd tuned truck or one here, sd tuned vehicles will have maf codes, they must in order to revert to sd after failing maf.
but there is a wrong way to disable those maf codes that will cause the pcm to not fail the maf and revert to sd.
then the truck runs like sh*t

[jetmech]

I'll take a look at the next sd tuned truck or one here, sd tuned vehicles will have maf codes, they must in order to revert to sd after failing maf.
but there is a wrong way to disable those maf codes that will cause the pcm to not fail the maf and revert to sd.
then the truck runs like sh*t

I've run SD tunes in the past and never seen a MAF code. That is what has me concerned.

[farmtruc]

I checked yesterday. Those two codes are normal for sd.
Mad has to fail and report code or it won't revert.
Maf fail hz has to be 0

[jetmech]

Got it. Next question:

If the truck is in "limp mode", would it behave as I have described in my original post? I've heard of a bad knock sensor throwing the PCM into limp mode and causing a great deal of hesitation during acceleration. However, even if this is the case, the truck is not throwing knock sensor codes.

[farmtruc]

If the pcm goes into limp mode u will know it.
Throttle will be unresponsive and you will not be able to acell. U will have to disconnect the battery and reset the dtc's.
Bad knock sensors wil cause a loss of power but that needs to be scanned and not timing and kr.
The pcm will pull timing if knock is detected.
You will feel a stumble.
I'm not pointing the finger at all just going off what ur stating.
It could be a lean condition. An intermittent open on a wire or sensor. Etc.

Anyway to get it scanned and post the *.hpt scan?

[jetmech]

It stumbles like crazy, I hit the throttle and hold my foot steady, yet the truck behaves as though I am tapping the throttle. I can make it into second gear, beyond that I lose all faith in the truck and slowly roll back to the garage. No knock sensor codes, although it feels like it's in limp mode.

[farmtruc]

need to get a scan going on it and study and find out what's going on.
could be fueling, timing.

if you wanna feel rep mode, unplug your throttle body connector, that's rep mode, no power.