VX VY PCM bin swapping = brick ahhhh :(

[TTVN]

hey guys
since there arent any vx xdf's for the flash pcms i just tried flashing a vy bin to a vx pcm and app was good until it came up something about the checksums giving 2 options and i clearly picked the wrong option and bricked the pcm and now it s dead and wont connect

i have 1 more pcm here and can use it but i dont want to brick it so does anyone know what i did wrong?????

any ideas thanks Rod

[VL400]

If it wrote OK and is just the checksum thats wrong you should still be able to connect, have you power cycled it as it may be stuck in some RAM loaded routines?

Did you program the internal EEPROM from a bin you downloaded on here? It would have asked you if you wanted to clone the PCM, if you selected yes it might cause issues as it will just be a blank EEPROM now - the warning message outlines when cloning should be used.

[TTVN]

yes mate i tried to load a bin off here into it and im pretty sure its blank and dead in the water

is there a way i can put a bin off here onto the pcm without screwing it up ?????

i cant find any xdf files for the vx bins thats all

thanks rod

[VX L67 Getrag]

I'm pretty sure the VX & VY naturally aspirated xdf's are based around the same so either should work!
Don't quote me on it just pretty sure!

[VL400]

Should be able to write a VY bin but if the EEPROM is erased (if you answered yes to cloning) it might be game over - I never tried as I only had one bench PCM and didnt want to break it! But basically if you power cycled it and its still no good will need to lift the flash chip and program it again. If your trying to program it in the vehicle it may need to be removed - have had more success recovering when there is nothing else on the bus. There is a recovery segment in the PCM (same code in VX and VY) that allows you to still connect in case of a bad write, I dont erase this using the normal write bin or write cal routines so should always be recoverable - in the early days using different RAM loaders I overwrote part of that and had to recover Yoda69s PCM, was still able to without lifting the flash chip though. Last chance there is a PCM recovery option in the flashtool but need to be able to connect to the PCM for that to work.


VX and VY are similar but not totally the same so some parts line up ok.

[darcy]

Definately power cycle it if you havent already TTVN.

When I flash my VY in the car, if I don't have the checksum correct before I write the bin, something must time out no matter how quick I hit che pop-up window ok button.
When this happens, the PCM doesnt reset properly, and I have to manually power cycle it by pulling the fuse under the bonnet and turning the ignition on with the fuse out.
Then it will fire back up again no problems. Otherwise I cant conenct with the flash tool and car won't start.

I haven't yet successfully cloned a PCM, have a spare here, howver seems to not be able to write one particular byte.
Plan on trying it out of the car to see if I have any better luck.
Slighty OT, but what's the miminum I need to connect to bench flash? Just power, gnd and comms?

[TTVN]

thanks guys ill have another go at it tomorrow

please correct me hereas im new to the flashing thing lol

so i can write a VY bin to the VX pcm no problem just dont chose to clone

also whats the go with the checksum thing and how do i know what its supposed to be so it doesnt trip me up and crash another pcm as it only bricked after the checksum screen that displayed the 2 checksums????

am i supposed to read the pcm first that i want to write to and clear the ram stuff first them load the other bin?????

sorry for the noob questions lol

[VL400]

The no-start/locking up issue with the wrong checksum is something I am trying to sort out but I just cant see why its doing it. So until TP can support the flash PCM checksum (using a plugin) its something that I will need to keep looking in to.

The write bin function erases and writes the entire flash chip except the last sector (16k). This sector contains the boot code and ALDL code so it must stay to be able to enter mode 5/6 and start uploading the flash reading and writing routines. If you choose to clone the PCM it also writes the CPU's EEPROM which contains the VIN, fault logging and all security related stuff. So for cloning you must do a 'Get Bin' of your existing PCM and then choose NO when it asks to clear the registers - this leaves the EEPROM data intact so it can be programmed to your new PCM using 'Write BIn' and saying yes to clone it. If you clear the registers you will get a raw bin file like the ones posted on this site. Cloning means nothing in the vehicle knows that the PCM has changed and it stays linked to the BCM.

Something I have not tried is erasing the CPU EEPROM by doing a 'Get Bin', saying yes to clear the registers and then using that bin to clone the PCM. Which would be the same as cloning the PCM using a bin from this site.

[TTVN]

ok so i should be able to clone the existing pcm to transfer the security stuff into the other pcm

then i can load a bin off the site into the cloned pcm but not select the clone option when loading the bin

when it asks which checksum to insert which do i use the one in the pcm or the one in the bin???

thanks for the help is appreciated

[VL400]

Depends what you are trying to do, if you have an existing VY PCM and are wanting to use a VX PCM in its place - Do a 'Get Bin' on the VY and do not clear the registers when it asks, then do a 'Write Bin' using the bin you just got and do a clone PCM when it asks. You will now have an exact copy of the original. For tuning just use the read and write cal functions from then on.

I have not checked to see what difference there is in the EEPROM mapping from VX to VY, so cannot say for certain that if you write a VY bin (with cloning) and then a raw VX bin (without cloning) it will still work ok.

You will need to press ok and use the calculated checksum if you get the message (its entered in the box ready to go) and want the checksum fixed - although a few few factory bins do not have the correct checksum just use AA to bypass it.