2001 Silverado 4.8ltr

[GAMEOVER]

I keep having this weird problem, the STFT's & LTFT's all go to zero and FUELSYS Pid is showing "OL FAULT" or "UNKNOWN".... I have tried resetting the fuel trims with DVT controls but no change... The truck is stock except for exhaust & CAI.
This is happening at cruise and part throttle. The first 10 mins of logging shows active STFT's & LTFT's and then all of sudden the trims go to ZERO and FUELSYS show's "OL FAULT" or "UNKNOWN"
Also, I noticed that when I do go into WOT my AFR is not showing what I'm commanding almost like it's not going into PE mode. I removed all the delay's & such. IDK maybe the fuel pump is going bad...Any ideas?

[joecar]

Log the HO2Sx1 voltages and see what they are showing.

[GAMEOVER]

I'll give it a try...

[GAMEOVER]

The fuel pump went out a couple of days later before I got a chance to log the O2 voltages...(everything is good now with a new pump:D)

*** On a different note: I'm having problems with a 2005 Silverado 4.8ltr..."Bootloader Rejected"....The truck has aftermarket stereo, dvd, tv's e.t.c
I've unplugged fuse's, removed power from amplifier's, tv's and I still get the "Bootloader Re-jected" error message... If I remove the computer and "Read" the stock file with a bench harness and then re-install the computer would I have to do a Vats or crank re-learn??? It's the only way I can figure to Read the computer because of all the stereo crap!!!:help2::help2:

[GAMEOVER]

Anyone???

[joecar]

You shouldn't have to do a VATS relearn because it is the same PCM that you're bench flashing... that's my understanding (I asked someone for a sanity check).

I'm not sure why you're getting Bootloader Rejected.

[GAMEOVER]

Thanks Joe,
I just wanted to make sure before I removed it. I assume I'm getting the "Bootloader Re-jected" because of the aftermarket stereo equipment???
IDK :nixweiss:

[GMPX]

VATS doesn't need to be redone after a bench flash, assuming it's going back in to the same vehicle it came from.

Cheers,
Ross

[GAMEOVER]

Message that appeared when trying to Read stock file, after about 10 seconds of Read when EFI Live was calculating how long it would take.....This is the message that shows up:

"Bootloader Rejected"
"Error" "Read Failed" PCM has returned to normal operation...Retry in 1 second"

[Blacky]

I got the blx files you sent. There's something weird going on with your PCM. Is it possible the power supply or ground to the PCM is faulty. For some reason and without warning the PCM is just rebooting. A brief power short may be responsible.

Does it read ok using a bench harness?

Regards
Paul

[GAMEOVER]

Yes it read OK with a bench harness, I tried to scan it, but it won't connect thru the OBD2 port... I'm thinking there might be a short(like you say) between the OBD2 port and the PCM. I'll check the ground and the power supply tomorrow morning...Thanks!

[GAMEOVER]

Log the HO2Sx1 voltages and see what they are showing.

New fuel pump fixed problem for about a week...:D I logged HO2 voltages and after about 10 mins of driving they would dip to about .065 -.085 and stay there, STFT'S & LTFT's show "0" and the fuelsys pid would show "OL FAULT" DTC's show Bank 1 & 2 O2 sensor low voltage... I guess I need new HO2 sensor's :shock:

[joecar]

Yes, sounds like bad O2S's... how many miles on them...?

[GAMEOVER]

125,000 miles.....:doh2: