Chips in a OBDII PCM?

[mattbarn]

It can be done if you find a way to hold the MCU in reset while you flash the ROM.

[mekkis]

It can be done if you find a way to hold the MCU in reset while you flash the ROM.

I haven't paid attention to MCU architecture, but it "should" have a RST pin. Before Moates came out with the Ostriches I had an old school EconoROM 3, it would pulse the RST pin of whichever MCU after flashing to reboot it.

[evilstuie]

Hey Guys,

I'm very interested in this after bricking two PCMs from attempts at an OS flash with Dimented's LS1 Flash tool. Cal flashes work fine, but it bricked both PCMs trying to flash an OS and cal despite following all instructions.
And here in Australia, the cheapest you can get a 0411PCM for is about $100-$150, so I'd much rather have the option of flashing these directly and reinstalling rather than buy additional PCMs till I get one with the right OS.
I've ordered a TL866A EEPROM programmer from ebay, and looking at the heat gun method for removing and reinstalling the flash chip to read the flash, hopefully decipher what screwed up, and then reflash the full BIN onto it before reinstalling.

Before the programmer arrives, which orientation does the chip go onto the programmer, and what is the procedure for flashing the BIN onto it, I've read somewhere something about inverted byte flash but that's about it.

Also regarding the reset someone mentioned, I found the datasheet on these AB28F400B chips that mentioned there's a reset/powerdown pin on the chip you can ground/power to perform a reset, the pin details and functions are on the datasheet here:
http://pdf1.alldatasheet.com/datashe...F400B5B80.html

I was hoping I could put the PCM in recovery mode using this, but I didn't understand it completely, and figured it would still be useless without a modified version of Dimented's program to have additional code to force flash anyway, if that even is an option.

[LRT]

after bricking two PCMs from attempts at an OS flash with Dimented's LS1 Flash tool. Cal flashes work fine, but it bricked both PCMs trying to flash an OS and cal despite following all instructions

The flash program created by dimented24x7 was for the 12200411 PCM (2001 & 2002), and specifically for OS 12202088 (2001). It should be OK for use with OS 12208322, 12209203, 12212156, and with OS 12225074 (if this OS was from a 2001 or 2002 model year vehicle).

If you try to flash any other OS, then there is a good chance of bricking the PCM. The best course of action is to read the 0411 PCM with this flash tool, and then to only reflash the PCM with the base calibration previously read out. You can alter this base calibration as necessary, including swapping various segments.

Also, if you try to flash a 9354896 PCM (1999 & 2000), which is often used as an 0411 replacement, there is a good chance of bricking the 4896 PCM.

[evilstuie]

The flash program created by dimented24x7 was for the 12200411 PCM (2001 & 2002), and specifically for OS 12202088 (2001). It should be OK for use with OS 12208322, 12209203, 12212156, and with OS 12225074 (if this OS was from a 2001 or 2002 model year vehicle).

If you try to flash any other OS, then there is a good chance of bricking the PCM. The best course of action is to read the 0411 PCM with this flash tool, and then to only reflash the PCM with the base calibration previously read out. You can alter this base calibration as necessary, including swapping various segments.

Also, if you try to flash a 9354896 PCM (1999 & 2000), which is often used as an 0411 replacement, there is a good chance of bricking the 4896 PCM.

So you're saying the OS's don't work on that hardware, or dimented's program is flawed?
The program is a flash tool, and a binary is a bit perfect copy of the data, so if the flash chip is identical, why would the difference in OS matter if its copying the whole contents?
Also the first PCM was the 411pcm and compatible tune, theOS that brickjed that was the 12208322.

I know the fault was mine four trusting home brew software instead of buying the commercial option, but I thought he had put together a working program.

[LRT]

So you're saying the OS's don't work on that hardware, or dimented's program is flawed?

The flash program written by dimented24x7 works with a specific PCM and OS. It does what he wrote it to do, but it is not a universal flash tool. The 1999 & 2000 PCM use a different flash protocol than the 2000 & 2001 PCMs.

The program is a flash tool, and a binary is a bit perfect copy of the data, so if the flash chip is identical, why would the difference in OS matter if its copying the whole contents?

It doesn't work like that. The flash tool programs data within a predefined area of the PCM's flash memory. It does not flash the area where the VIN and PCM's serial number are located, nor does it flash the "slack" space. One of the issues is that some calibrations (OS) occupy slightly different areas of the PCM's flash memory - so sometimes not all of the calibration gets written - which will brick the PCM.

Commercial flash software has been designed to recognize the calibration that is currently resident in the PCM, and the calibration that has been selected by the user to be written into the PCM, and compensates accordingly (when possible).

[evilstuie]

The flash program written by dimented24x7 works with a specific PCM and OS. It does what he wrote it to do, but it is not a universal flash tool. The 1999 & 2000 PCM use a different flash protocol than the 2000 & 2001 PCMs.

Oh ok, but If its a different protocol why could it read and write the flash?