Unbricking Ls1 Based PCM"S

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j_ds_au
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Re: Unbricking Ls1 Based PCM"S

Post by j_ds_au »

Without a schematic (I'm guessing nothing close is available), I'd say you should find a way to hold the MCU in reset, so it (hopefully) won't be trying to drive the Flash pins in conflict with your programmer. Otherwise you risk blowing up your MCU and/or programmer. Don't use device type auto-detection, as that will put a high voltage on A9 (if I recall), which will almost certainly blow up your MCU.
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Re: Unbricking Ls1 Based PCM"S

Post by Tazzi »

Theres been a few people have plenty of success with a BDM programmer. http://www.usbjtag.com/jtagnt/ecu411/index.php
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j_ds_au
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Re: Unbricking Ls1 Based PCM"S

Post by j_ds_au »

Tazzi wrote:Theres been a few people have plenty of success with a BDM programmer. http://www.usbjtag.com/jtagnt/ecu411/index.php
Sure, since programmers usually have strong pin drivers that typically are able to overpower the outputs of an MCU. Nevertheless the caution remains, you risk damaging the MCU unless you are able to tristate its outputs by holding it in reset.
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Re: Unbricking Ls1 Based PCM"S

Post by antus »

The BDM talks to the CPUs "Background Debug Mode" interface, and the ecu411 stuff there includes code which I believe implements a passthrough from CPU. So its PC talking to usbbdm-nt interface, talking a standard in circuit interface to the 68k, which is driving the flash. Its probably the safest and simplest way to go, and you get read+write after your connected to the board. Simpler than removing the flash IC, though thats possibly debatable by those who have the right tools and the skills. I'd go the BDM, specifically USBBDM-NT as they have the '411 specific implementation and connection docs for the hardware platform.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
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Re: Unbricking Ls1 Based PCM"S

Post by commodorenut »

antus wrote:The BDM talks to the CPUs "Background Debug Mode" interface, and the ecu411 stuff there includes code which I believe implements a passthrough from CPU. So its PC talking to usbbdm-nt interface, talking a standard in circuit interface to the 68k, which is driving the flash. Its probably the safest and simplest way to go, and you get read+write after your connected to the board. Simpler than removing the flash IC, though thats possibly debatable by those who have the right tools and the skills. I'd go the BDM, specifically USBBDM-NT as they have the '411 specific implementation and connection docs for the hardware platform.
I removed the flash IC from the board and reflashed it....
That worked a treat.

Next ill give theUSBBDM-NT programmer a go

It would be great if we could build something that could do it via OBDII port.
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Re: Unbricking Ls1 Based PCM"S

Post by antus »

But it needs to be not bricked with a running os to talk to the vehicle data bus, so catch 22 there! You just need the bootloader working, but then its not the definition of bricked.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
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Re: Unbricking Ls1 Based PCM"S

Post by j_ds_au »

antus wrote:The BDM talks to the CPUs "Background Debug Mode" interface, and the ecu411 stuff there includes code which I believe implements a passthrough from CPU. So its PC talking to usbbdm-nt interface, talking a standard in circuit interface to the 68k, which is driving the flash. Its probably the safest and simplest way to go, and you get read+write after your connected to the board. Simpler than removing the flash IC, though thats possibly debatable by those who have the right tools and the skills. I'd go the BDM, specifically USBBDM-NT as they have the '411 specific implementation and connection docs for the hardware platform.
Ah, gotcha! Yes, that sounds like a safe option. Earlier in this thread, SOIC clips were mentioned, which implied piggy-backing the Flash and interfacing directly to it ...
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Re: Unbricking Ls1 Based PCM"S

Post by commodorenut »

I must admit these USBBDM-NT are awesome,
Unbricked 20 Pcms today, Very quick and easy to do
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