LS1B Bricked?

[Burnett03]

I flashed in the custom os for my 2005 silverado because I'm preparing the truck for boost. Then flashed in the cal file. Truck started and ran so i read the file and saved it so i could change all the values to prepare for boost. I decided to flash the stock tune and stock o/s back in so i could drive the truck later. Right when i started flashing the truck i realized the key wasn't on so i made the dumb mistake of cancelling the flash. EFI live cancelled the flash but now i can't communicate to the ecm. When i hit auto-detect it doesn't detect the ecm. I tried pulling the negative battery cable and pulling ecm fuses. Also tried resetting the computer but i still can no connect to the ecm. From research on here it seems like i bricked the ecm. Thoughts?

[Blacky]

If it was only a cal-flash then the PCM should be fine. However it will be in dead-poll mode. That is a state where it has no calibration and cannot "identify" itself to EFILive so the auto-detect does not work. You should be able to just restart the flash process and it should recover the PCM.

Regards
Paul

[Burnett03]

It was a full flash. I was going from a custom o/s back to the regular o/s.

[Blacky]

If it was a full flash then yes it is probably bricked. It can be recovered by removing the flash chip from the main circuit board and reprogramming the flash chip in an external flash chip programmer. I believe SoCal Diesel offer that service.

One way to know for sure is after hooking up FlashScan, watch the orange LED second from the right. If it blinks rapidly (4 times per second) all the time, then the PCM is in dead-poll and should be recoverable. That contsant blinking is the PCM "asking" any connected tool for a new calibration. If it blinks just a few times and then stops then it is bricked, in that case the initial burst of blinking is attempting to contact the PCM.

Regards
Paul

[Burnett03]

Thank you for the reply Paul. I'm sure it is bricked, and i learned an important lesson from this. I sent it out today to PCM Calibrators to reflash the chip and get me back on the road.

[Blacky]

We've all done it at least once, some more than once :)

In future if you ever do interrupt a full-flash (before it's about 15-20% done), keep power supplied to the PCM as long as possible and keep restarting the flash process until it completes successfully.

During a full-flash the EFILive software sends up a custom piece of software (called a boot loader) that is placed in the PCM's RAM* and executed. The boot loader takes control of the PCM and is responsible for communicating with the EFILive software and reprogramming the PCM with the data that EFILive sends to it. So long as power is maintained to the PCM, that boot loader will continue to run in the PCM's RAM - waiting for another full-flash attempt. Once a full-flash is complete the boot loader terminates and returns control to the PCM.

Obviously if the flash does not complete at least the first 15-20% and power is removed/restored, then when the PCM powers up there is not enough of the operating system in the PCM to be able to communicate with FlashScan (or any other tune tool) effectively bricking the PCM by preventing it from communicating with the outside world.

* Random Access Memory or volatile memory, memory that is lost when power is removed (i.e. not flash memory which is where the OS and calibrations are stored).

Regards
Paul

[joecar]

Very good refresher course (on full flash, don't remove power, just try flashing again), thanks Paul.


If it was a cal-only flash, then I take it the PCM is using its own loader (i.e. resides in the non-cal part of flash)...?

:)

[Blacky]

If it was a cal-only flash, then I take it the PCM is using its own loader (i.e. resides in the non-cal part of flash)...?:)

Correct, the GM VPW comms code is in the operating system. During a full-flash the operating system is also erased which means the GM VPW comms code is erased. The only way to communicate with the ECM after the full-flash is erased is via the EFILive boot loader running in RAM. If power is removed that boot loader in RAM is gone and the PCM is a brick. The full-flash boot loader will continue to run forever so long as power is maintained to the PCM.

Note: that is different to the cal-flash boot loader which will eventually self terminate if FlashScan is no longer communicating with it. But a failed cal-flash is always recoverable.

Regards
Paul

[Tre-Cool]

I killed my 1st ls1b the other week myself on the bench. efilive itself froze and since i had no idea at what stage it was at, made the mistake of turning the ecu off

[GMPX]

GM did things better after the LS1 PCM by putting a bootblock in the ECM that never needs to be erased or programmed, this way if the OS and cals are erased the ECM still has enough in there to be able to communicate with a reflash tool. You can't blame them though as these PCM's weren't designed to be flashed multiple times per day, just a couple of times at the dealer in the life time of the car was probably what they designed them around.

[Burnett03]

Thanks for all the help guys. Got the ECM back from pcmcalibrators.com today and got the truck running. However when i went to connect to the ecm efilive told me i needed to license the ecm. So i had to use up one of my extra vin licenses. I was under the understanding that when i sent the ecm to pcmcalibrators to be fixed i wouldn't need to relicense the ecm or use one of my vin licenses. So now i'm down a vin license. Anyway i can get that one back or do i need to just suck it up and purchase another one? If so i understand, it's my own fault for bricking it. Thanks again!

[GMPX]

Edit: Sorry my post was incorrect.

Cheers,
Ross

[Blacky]

Thanks for all the help guys. Got the ECM back from pcmcalibrators.com today and got the truck running. However when i went to connect to the ecm efilive told me i needed to license the ecm. So i had to use up one of my extra vin licenses. I was under the understanding that when i sent the ecm to pcmcalibrators to be fixed i wouldn't need to relicense the ecm or use one of my vin licenses. So now i'm down a vin license. Anyway i can get that one back or do i need to just suck it up and purchase another one? If so i understand, it's my own fault for bricking it. Thanks again!

Send your FlashScan serial and auth-code to me paul@efilive.com and I'll send you a replacement VIN license so you can re-license it.
Regards
Paul

[Burnett03]

I'm unsure what AJ did wether he fixed the chip or swapped ecm. I was under the impression he was fixing mine. Either way it's back up and running now, just had to use my extra license. I'll be more careful in the future when flashing.

[Burnett03]

Thank you for your help, I sent you an email. I think the problem lies in the fact that AJ from pcm calibrators put the incorrect engine # in the calibration file. He put "O" instead of "0' (zero) That's what i had to re-license the ecm.

[Burnett03]

Paul did you ever get my email?

[Blacky]

Paul did you ever get my email?

Yes, I did. Sorry, I dropped the ball on this. I'll send a replacement VIN asap.
Regards
Paul

[Burnett03]

Thank you for all your help.

[Phil_Miller_86]

If it was a full flash then yes it is probably bricked. It can be recovered by removing the flash chip from the main circuit board and reprogramming the flash chip in an external flash chip programmer. I believe SoCal Diesel offer that service.

One way to know for sure is after hooking up FlashScan, watch the orange LED second from the right. If it blinks rapidly (4 times per second) all the time, then the PCM is in dead-poll and should be recoverable. That contsant blinking is the PCM "asking" any connected tool for a new calibration. If it blinks just a few times and then stops then it is bricked, in that case the initial burst of blinking is attempting to contact the PCM.

Regards
Paul

I know this is an old post, but I think it's relevant to my issue with the hypertech and I think this part in particular is very helpful. Besides the light flashing, is there another way to tell if the PCM is bricked vs dead polled? If I can pull a file from the PCM with invalid checksums, does that indicate dead poll?

To recover I would just need a "good" file and a full flash?

[Blacky]

If you can read a file from the PCM, then you should be able to flash it without any issues.

If the operating system segment checksum is OK, then you only need to cal-flash it.
If the operating system segment checksum is faulty, then you'll need to full-flash it.

If you need to do a full-flash, I suggest doing a test full-flash first. That will go through all the motions of actually full-flashing it without actually altering anything in the PCM. That will give you confidence that a real (non-test) full-flash should complete successfully.

Use this option to do a test flash:
23896

Regards
Paul

[Phil_Miller_86]

Thank you Paul. This makes me feel a lot better, now that I have a plan. I appreciate your response.