Bootloader-

[GMjohn]

Just a general question to place on the floor for discussion-

Situation- Customer had an issue using brand x hand held programmer.
My guess would be a low voltage situation part way through programming causing programming to fail. On the older PCMs this would be terminal.

I was told the bootloader on an E38 can not be damaged by programming.
Oddly enough the E38 was a no start but would still communicate with a tech 2. I tried to reflash with a tech 2 and sps but the ECM would not enter Hi speed mode. Per customer request I spoke with brand X tech support.
Nice guy, I was told no matter what I should be able to fix any of their programming issues with a tech 2 and sps. I had to remove the ECM and send back to brand x and they reflashed back to stock. I was told they use GM sps to fix flash issues but I have been unable to on several ECM's.

I have seen this situation using SPS and had to replace the ECM to get the vehicle running again.


Any tricks anyone is willing to share on how to repair a failed flash attempt?

The ECM's are still online but will not reprogram using factory equipment.

Will FlashScan repair this situation? If so will it require a license to restore the stock flash? Any way just hoping for a few comments from anyone on this situation.

Thanks,

John

[GMPX]

John,

Yes we could recover an E38 from this situation and yes it would require a license.
Next time, select Replace ECM from the SPS menu, then the ECM will be treated as brand new. I think in this situation it then allows you to manually enter the VIN to continue on rather than bombing out saying it can't communicate with the ECM.

Cheers,
Ross

[GMjohn]

Ross,

Thanks for the reply. The E38's I've tried to recover will still communicate but will not pull the vin from the ECM. This will force me to reflash as new and enter the vin. It appears to work but usually fails when on the attempt to enter high speen mode. Made me wonder if I would have better success benching the ECM without all the chatter. I pulled the fuses from the troublesome modules, still no go. Just made me wonder if some special process is needed. I will try again on the next one I get. Brand X was able to flash a module I was unable to restore. Just wondered If flashscan or any other software used a different method than GM sps. ( Your opportunity to give flashscan a superior plug) Anyway, thanks for the reply-

John

[ScarabEpic22]

Ive never benched an ECM, but Ive heard Jesse scream about other modules that keep "talking" when you try to flash, causing it to fail (aftermarket stereo maybe?).

[GMPX]

ok, a bit of confusion here. High Speed mode on CAN does nothing, CAN is just in high speed mode always. CAN is generally unaffected by other modules chatting on the bus (unlike the old VPW bus on the LS1 etc).

Before I continue on I'll clear up one thing.
A bootloader is a small program sent to the ECM's RAM to perform the reflashing.
A booblock is part of the flash memory that allows the ECM to powerup and have limited communications. This is what the LS1 PCM was lacking.

We use a totally different method to SPS, I wrote the reflash bootloaders for reflashing the E38 to suit EFILive. Which is why when you have a dead E38 we will be able to reflash it without caring about the VIN number etc.

Cheers,
Ross

[GMjohn]

Ok, things are clearing up a bit.


I can remember from school when we were using a MOT 5206E a protected BootBlock that as students we were unable to kill. Until the point I discovered the flash protect jumper and had the BDM hooked up. That was the start of a long evening learning how to restore the bootblock.

I was never clear if "Tech 2 - switching to Hi speed" was an actual speed change or just switching to block tranfer. Anyway- I was mainly interested in the boot issues.

So in my mind- Bootblock is ok, Can't be damaged with sps or other tuner software. Application code - cooked. So on start up all registers etc are being set up (explains why the ecm boots) but the unprotected flash is corrupt.

Ross- Many thanks:master:

John