Boot loader rejected, custom key?

[Wheelz]

Tried tuning an LB7 a couple days ago and hit a wall. Says boot loader rejected because the controller is locked with a custom key. Tried the $FFFF key and no bueno. Tried all various options of high speed/low speed flashing and v7/v8 and nothing could read the tune out. Also my v2 doesn't read the vehicle vin properly. I Got a string of random character. Do I tell him to get a dealer reflash or is there another trick I can try to get in there?

it has an aftermarket radio, but we pulled almost all accessory fuses one by one and still nothing.

I'm failrly new to using the V2. all of my experience so far has been using an autocal for the interface. If I'm doing something stupid please point it out. I've searched on google for a while now and haven't found anything that really confirms what's going on.

Thanks in advance

[GMC-2002-Dmax]

Did you try assume lock faulty or Alt Keys ??

Do you know the history of the truck, it may be a locked ecm and the tuner that locked can unlock it and put it back to stock.

Good Luck

[Wheelz]

Yup tried both of those.

No we don't know it's history. The owner is trying to find out right now. I didn't know if there was a way around it somehow or if someone could guarantee a GM flash will fix it

[GMC-2002-Dmax]

Can't get into it unless you know the new key.

If you can find a little history on it you might be able to get the ecm unlocked with the proper seed key

[Wheelz]

Ah bummer. Even GM needs to know the key then?

[Wheelz]

Bumpity

Any other thoughts on GM being able to flash it?

[ScarabEpic22]

If an ECM/PCM is secured with a custom key and you dont know it, its worthless. You cant read (usually) or flash it so its not worth anything.

GM wont be able to brute force flash it, you can only flash an unlocked ECM/PCM with a Tech II (AFAIK). If you cant source another ECM, you'll have to send the ECM to someone who can disassemble it and bench flash the memory then put it back together.

Sorry bud, this kind of thing sucks. Do you know who tuned it before?

[Wheelz]

The owner is making a call to a shop who might've. But otherwise no clue.

Is there anyway I can load a list of keys to try with EFI to attempt a brute force unlock on my own?

[puddlestomper]

Any word on how to fix this? I'm running into the same thing. Almost to a T.

[GMC-2002-Dmax]

You can start with 00001 and try all the keys in order to 65350 or so one at a time.

If you figure each attempt will take about 15-30 seconds to try the key and then shut it down for 15 seconds it will only take you 45 days to try all the keys doing this 24/7.

You can send the ecm to Socal Diesel and they can fix it.

661-775-5620 and ask for Guy Tripp

[dansdieselp]

Have you tried unchecking the high speed option when when trying to read? Had a lb7 do the same thing to me the other day. Pull both Radio and Info fuses and give it a try.

[GMC-2002-Dmax]

If you place the ecm on a bench harness and it cannot be read it's locked with a custom key.

If it was flashed previously by a handheld tuner and it hosed the seed key its screwed, very common.

If he wants to swap the ecm into another truck that reads/writes fine that can be done as a test to rule out an issue in the truck.

In my experience only aftermarket radios/ipod adapters/alarms will cause issues and usually the 2001/2002 are less susceptible to problems unlike the 2003-2010 trucks with CAN/BUS

[THEFERMANATOR]

If you place the ecm on a bench harness and it cannot be read it's locked with a custom key.

If it was flashed previously by a handheld tuner and it hosed the seed key its screwed, very common.

If he wants to swap the ecm into another truck that reads/writes fine that can be done as a test to rule out an issue in the truck.

In my experience only aftermarket radios/ipod adapters/alarms will cause issues and usually the 2001/2002 are less susceptible to problems unlike the 2003-2010 trucks with CAN/BUS

Unless your like me with a pissed off BCM, then the 01/02 system gets pissy ALOT trying to flash. Many times I have to unplug my BCM to flash with the V7 software, but it always seems to work in V8(for me anyways).