Where to start?

[Drew_au]

G'day everyone,

I've been trawling the 'net for days learning more about ECU programming but I'm having a few problems piecing the final picture together.

As a bit of a background, I'm building a 1938 Wolseley street-rod with a VT Holden 5 litre V8 engine. I've only just started out and I picked up my engine yesterday. I need to alter the status of the VATS (I think that's the right acronym) on the PCM as I'm not using the standard Holden BCM so unless the PCM has been modified with a different memcal the engine will not start without the serial data from BCM. I also wouldn't mind being able to use hotted up programming for the PCM although this isn't my main priority at this time.

I'm reasonably tech-savvy (for an old bloke), I have an Electrical Technology qualification and work in electronics, computers and communications. I've been kicking about cars since I was 14 (like most gear-heads) and I also have the full set of factory manuals for the VT Holden Commodore. Despite all this I'm struggling coming up with the complete how-to.

As far as I understand it I can read/alter the program in the PCM using TunerPro. I can connect using a serial link (via a MAX232 interface and some modifications to the PCM ) using AntusPro and this enables reading and writing the PROM as well as real-time data collection.

So I need to:

• Modify the PCM to accept a serial connection.
• Construct (or buy) a MAX232 based serial interface to connect to my USB serial interface on the laptop.
• Use TunerPro to read the program on the PCM. I think I need some sort of definition file to interpret the data that is read?
• Use AntusProm to enable reading and writing of the PROM on the PCM.

Have I got the right handle on this? Is there a better way? My head is spinning! I don't expect to be spoon-fed but I am struggling getting the entire picture together.

Thanks all,

Andrew.

[yoda69]

To start with download one of the VT V8 TunerPro definitions from here: https://pcmhacking.net/forums/view ... ?f=7&t=315
Note that these are for TunerPro V5 and will not work with V4.
I would suggest an EEPROM reader/programmer to start with, using the above link you should be able to disable VATS depending on the variant of original bin file (read through above link for details)
You will also require a UV Eraser or remove the EPROM and replace with EEPROM, they are 27C010 (128k) 32pin DIP chips.

This will at least get you running.

Realtime tuning for the VT is still inprogress with TP5 and Moates Ostrich and we are still having some teething problems, hopefully these will be resolved over the next couple of months.

Good Luck,
yoda69

[antus]

You only need to modify the PCM for 8192 baud serial on the original '808 computers from the VN/VP commodre, camira, astra, nissan pulsar N13. VR and later can do 8192 baud out as is, so for your VT V8 this will not be required. As yoda says you'll only need to change the VATS flag and reburn the prom and you'll be away.

[Drew_au]

Thanks for the speedy replies everyone,

So the only way to modify the program is to re-burn the PROM or to burn a new PROM? There is no connecting to the PCM to modify the program - that's only for real time logging?

Thanks for the link to the XDF files. How do I know which one suits my PCM?

So I take it that the XDF file is like a template ready for the actual data, do I need to read the data from my PROM to populate the fields.

Thanks,

Andrew.

[Holden202T]

the info in the chip is what had all the data, the xdf is just a way of displaying all that data so its in easy to use tables and graphs etc.

as far as knowing which one suits your pcm you need to see what the current chip has on it .... there should be a sticker on the chip and it will tell you what you need xdf wise ....

just for my own interest ... what pcm does vt 5ltr use, is it like the vr/vs v8 pcm or is it more like that vt v6 pcm ?

[Drew_au]

just for my own interest ... what pcm does vt 5ltr use, is it like the vr/vs v8 pcm or is it more like that vt v6 pcm ?

Um... I'd like to be able to answer that question but I'm not sure...

I'll have a close look when I'm up the shed tomorrow.

Andrew.

[Holden202T]

just get the details off the sticker, like the service number etc that should answer the questions.

[yoda69]

The VT V8 Memcal is like the VS/VT V6 ones, short stubby with no knock sensors or Netres and is a 128k bin file.
If you compare the 4 letter code of the sticker with what's listed where the xdf is you should be away.
You need the Serial cable data with max232 or similar for datalogging, I put an ADX (like and xdf but for logging) up here on another post somewhere, if you can't find it let me know and I'll try and move it over to where the xdf's are.

yoda69

[Drew_au]

Ok, I had a look in the PCM, my prom is marked CJDN.

So I guess my next step is to purchase a EPROM reader/burner and read the data off my chip, modify it to eliminate VATS, burn it back on the chip and viola, the beast should start. Sound reasonable?

Cheers and thanks again for your help everyone,

Andrew.

[VL400]

Yep and device ID to AA to bypass the checksum. The only issue is getting the cooling fans to work correctly. The low speed fan is controlled via the BCM so it will throw an error and leave the high speed fan on permanently. yoda69 and holden202 have the answers for a fix so hopefully they can post up the details for this.