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Originally posted by rmeyers202

Hello, I'm new to the forum and a newbie at programming, so I have some questions...

I just received my GQ-4x4 with ADP-019 (v 4.1) adapter. I am trying to read a AM29F800BB-70SE which is from a 2002 Isuzu Axiom PCM that I removed from the board so that I can change the VIN.

When the chip is read the bytes are swapped, so the VIN appears byte swapped.

My first question is, if the bytes are swapped, do they need to be written back to the chip that way, or should I swap them in the software using "Byte Swap" so the VIN reads correctly and then write to the chip that "swapped" version?

To be clear, the VIN of the car is say 123456, and when I read the chip it reads 214365. I use "byte swap" in the software so that it fixes the byte order to read 123456. If I want to change the VIN on the chip to 123457 should I write back to the chip 123457, or 214375?

Next question is the first read of the chip was different than the second read of the chip. The first read had the VIN stored at two different addresses, the first of which started at 6050, and the second started at 46050. Without doing anything to the chip or programmer I read the chip again, and the file was different, with the VIN only being at address 6050. The second read is much different than the first read. Which read would be correct? I tried reading the chip multiple times after, and they all matched the second read. I could not duplicate the first read where it had the VIN stored at two different addresses.

I tried multiple ways of writing the chip and nothing worked when reinstalling the chip on the board. The ONLY thing I changed was the VIN, first at both addresses, then byte swapped, then using the second read file to change the VIN only once, both as read and swapped. Nothing worked.

HELP!! :)

Ps.. This is a spare PCM to experiment with. I have a bench harness so I can power it up and connect a scan tool to it to verify VIN and proper operation. Prior to removing the chip from the board everything worked. That is no longer the case.

Meanwhile my vehicle runs perfect...so don't worry. ;)

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Originally posted by anniel

You need to write as the original with byte swap.

If you write the original file back does the PCM work?

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Originally posted by rmeyers202

quote:

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Originally posted by anniel

You need to write as the original with byte swap.

If you write the original file back does the PCM work?

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So if my VIN is 123457, and it reads 214375 on the read, I should byte swap so the VIN reads correctly in the buffer as 123457, and then write it that way, even though when I read the original it's swapped as 214375?

I did not try writing the original file back. I soldered and unsoldered the chip from the board so many times trying so many different combinations of the two different files, with different info swapped and not swapped, that one of the pins on the chip broke off. I ordered some new chips so I have to wait for them to arrive from China.

If I were to rewrite the original file back I would have to byte swap it in the buffer before rewriting it? Is that what you're saying?

In other words, if I read something and it appears byte swapped, I need to fix it with the "Byte Swap" option in the buffer so it reads correctly and write that fixed version?

When I byte swap it in the buffer so that it appears correct, and I write it that way, when I reread the chip after the write it reads correct, which is different than the original read which reads as byte swapped. So it reads different than the original reads.

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Originally posted by anniel
No you need to leave the formatting as the original. You can byte swap to edit what you want but you must swap it back to write to the chip. Good luck with chinese parts.

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Originally posted by rmeyers202

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Originally posted by anniel
No you need to leave the formatting as the original. You can byte swap to edit what you want but you must swap it back to write to the chip. Good luck with chinese parts.

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Thanks so much.

I'll try writing the original file back to the chip byte swapped as read and see if it works, when I get the new chip. There is no EEPROM on the board so it should be all in the AM29F800BB somewhere.

I have a bad feeling that I did not get a good read at all. I have 3 saved files from 3 different reads of the original prior to writing anything to the chip, and all 3 files are completely different. The first read is the only one that has the VIN at two different addresses, and the other two files are completely different when compared. I may have to buy another used PCM to get a good read on the chip... :)

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Originally posted by anniel

Was the leads clean and with good contact?

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Originally posted by rmeyers202

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Originally posted by anniel

Was the leads clean and with good contact?

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I'm not sure now. It was my first time using the adapter and I had to adjust the chip a few times before it was installed properly and it ID'd the chip. At first I got a few messages saying something about checking the installation in the adapter, so I did that. I reinstalled it and it ID'd properly and I read the chip.

Would it read the chip if it wasn't installed properly not making good contact on all the pins?

I was using a magnifying glass to inspect the pin contact in the adapter, and all looked good, but sometimes it didn't identify properly, so I would readjust the chip until it ID'd properly, then do the read.

I'm not exactly sure what happened now, it's all a blur because I read the chip so many times, with so many adjustments in the adapter, with so many error messages, and so many installations and removals of the chip from the board.

I thought it was a good read at the time, but now I'm doubting I ever got a good read because all 3 saved files are different.

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