2003 LB7 Won't Accept Program

illinoischris · 10-10-2009, 10:34 AM

New to the forum, new to Tuning, need some help!

Bought an 03 Duramax a few weeks ago, seems to run fine, but I don't have much in the way of history on it.

First, I purchased a used, but unlocked Hypertech PPIII to try to add some power. The tuner seems fine, followed all the directions, removed the right fuses, etc, but when it gets to the part about "programming in Progress", it spits out an error "7E". Called Hypertech, they went through all the obvious stuff, still no luck.

I chalked it up to a used programmer, so I next purchased a new PPE Xcelerator Tuner. Again, the tuner connects fine, can do diagnostics, reset trans, but when I go to tune engine, and it gets to "Unlocking PCM module" it spits out a long error code. I called PPE, they walked me through the obvious stuff, when that didn't work, they thought that perhaps the truck had an old tune not removed correctly and said that "95% of the time, that is the cause of the error" and instructed me to take it to the dealer to have them reflash ECM. Dealer Reflashed ECM with latest program. I asked them if they had any trouble with the computer, they said, no, it took the latest program no problem

Neither programmer will work still. They get so far to the point of programming and then error. Very frustrating. Fuses pulled, key on, no aftermarket electronics. I don't know what else it could be. Since I don't know much about the history of the truck, is it possible it has some type of aftermarket device which is blocking these but not the dealers tune? I'm not sure where to go from here. About to sell the tuners and say forget it.

Any ideas would be appreciated.

**ob_1jr** · 10-10-2009, 10:39 AM

to the forum!!

Did they have you check your cigarette lighter fuse?

illinoischris · 10-10-2009, 10:55 AM

No, but that fuse is good the outlets are hot

**ob_1jr** · 10-10-2009, 11:08 AM

I think there are 2 different fuses for that....not sure...but im not too sure about it then. Normally it is something with that fuse. I would make sure that everything is off inside. I dont pull the fuses on mine when i program it. I did the first few times, but didnt do it since.

.DmaxLb7. · 10-11-2009, 10:06 AM

I had this problem. I just got efi live, then everything got alot better!

LBZ_Duramax · 10-11-2009, 10:11 AM

The PPE wouldnt even power up if the Cig lighter OBD fuse was blown

Jonsey181 · 10-11-2009, 10:35 AM

The reason for it is because the cigaret lighter closest to the driver is the power for the OBDII port if you plug something like a cell phone charger in it and it doesnt light up good chance your OBDII isnt getting power

GOGODURAMAX · 10-11-2009, 12:10 PM

Did you check to make sure all wires and prongs are good and not bent?

jimmarla · 10-11-2009, 04:18 PM

I had the same problem, it was a fuse, cant remember which one it was though

mijdirtyjeep · 10-11-2009, 05:37 PM

If you are getting the error on the screen then the Programmer has POWER, and it is not a fuse. Mine will not take a CANNED tuner either, did all the things Quad wanted "including dealer reflash" and still would not load. Just send the PPE packing and get EFI, that worked on mine. I still do not know why, but with EFI I can not use high speed to flash a tune on it, but have to "used ALT Keys". Most likely the PPE is trying to load it with the high speed and is not smart enough to switch to "ALT Keys"