Electrical Issue (08 GMC Sierra)

[700 sportsman]

Hey guys, so my dad had his 08 GMC Sierra tuned last weekend by Justin (Black Bear Performance), and it runs great.

Today on the way home he said the headlights went off interior lights, radio everything went black, and the engine seemed to cut power for just a second. And when he got home, he shut the door and all the lights went out.
But now everything seems to be ok, remote start works, lock/unlock, and I went for a drive flashing the lights turning them on and off about everything I can think of, and I got nothing.

Now I think it was the PCM resetting, because that sound like similar to when Justin tuned it and the PCM reset. Is there any logic to this? Why would it just take a notion to reset?
Also I used my code reader, and there were no codes shown, none appeared while driving, and there were no stored codes.

Any ideas or input would be greatly appreciated.

Thanks in advance

 

[Bigredmariner]

All of the things you mentioned that went out are controlled by the BCM. May have been a fluke, or his BCM could have had a hiccup or is on it's way out. The BCM isn't able to be read by most hand held scanners unfortunately. If you had EFI Live you would at least be able to read the BCM codes.

 

[Darkanion]

If you had EFI Live you would at least be able to read the BCM codes.

Are you sure about that? I didn't think EFI Live could do anything (even read) the BCM, only the ECM, TCM, or PCM..?

 

[700 sportsman]

Yeh, I guess that would be the BCM. We'll have to see if it happens again.

Also when you unlock it should the parking lights flash twice? I can't recall if they did or not, but they do now, so that may be something?

 

[Darkanion]

Yeh, I guess that would be the BCM. We'll have to see if it happens again.

Also when you unlock it should the parking lights flash twice? I can't recall if they did or not, but they do now, so that may be something?

My '07 Sierra flashed twice on unlock..

 

[Bigredmariner]

If you had EFI Live you would at least be able to read the BCM codes.

Are you sure about that? I didn't think EFI Live could do anything (even read) the BCM, only the ECM, TCM, or PCM..?

Yes EFI Live will at least on the GMT800's and I don't see why they would change it from the 900's. I know because I have used it to read and clear BCM and TCCM codes already.

 

[Darkanion]

Yes EFI Live will at least on the GMT800's and I don't see why they would change it from the 900's. I know because I have used it to read and clear BCM and TCCM codes already.

You don't have to get snappy about it. It was just a simple question.. Geeez!

I thought the codes that were thrown were stored elsewhere.

I was pretty sure I had been told EFI Live couldn't "do" anything with the BCM. Whatever.. It's not like I can go check/test it anyway... lol:

 

[Bigredmariner]

Yes EFI Live will at least on the GMT800's and I don't see why they would change it from the 900's. I know because I have used it to read and clear BCM and TCCM codes already.

You don't have to get snappy about it. It was just a simple question.. Geeez!

I thought the codes that were thrown were stored elsewhere.

I was pretty sure I had been told EFI Live couldn't "do" anything with the BCM. Whatever.. It's not like I can go check/test it anyway... lol:

Snappy, WTF post are you reading?

You are correct that EFI Live can't do anything to the other modules, but it will clear codes only on the other modules. I have used it to clear the door module codes as well. But it will not allow you to change anything, like programming or the like.

 

[Texas Jim]

Yes EFI Live will at least on the GMT800's and I don't see why they would change it from the 900's. I know because I have used it to read and clear BCM and TCCM codes already.

You don't have to get snappy about it. It was just a simple question.. Geeez!

I thought the codes that were thrown were stored elsewhere.

I was pretty sure I had been told EFI Live couldn't "do" anything with the BCM. Whatever..
It's not like I can go check/test it anyway... lol:

You can check it on the Caddy...

 

[OldCracker29]

Yes EFI Live will at least on the GMT800's and I don't see why they would change it from the 900's. I know because I have used it to read and clear BCM and TCCM codes already.

You don't have to get snappy about it. It was just a simple question.. Geeez!

I thought the codes that were thrown were stored elsewhere.

I was pretty sure I had been told EFI Live couldn't "do" anything with the BCM. Whatever.. It's not like I can go check/test it anyway... lol:

Snappy, WTF post are you reading?

You are correct that EFI Live can't do anything to the other modules, but it will clear codes only on the other modules. I have used it to clear the door module codes as well. But it will not allow you to change anything, like programming or the like.

That got me

Tyler my '01 flashes twice also.