DIY: ECU Scantools/Data Cables

[michaelw]

ECU DATA LINKS
I have made one or two of these so I’d thought I would share some info I have found to help anyone who wants to make their own.

VN/VP:
There already is an excellent thread on this topic on the VN/VP forum How-to: Make a Diagnostic cable for your VN/VP Commodore. But I will add one or two things.

TRANSISTORS:
Almost any general purpose NPN transistor will do the job. The 2N2222’s are not so common in Australia. I would suggest that the BC548 would do the job nicely. Resistors are a much of a muchness. Any ¼ or 1/8 Watt will do the trick.

CABLE:
You do not need anything too special for this cable as the speed is not all that fast. Three core flex would do, but I would suggest that security cable would be better.
If you are going for a long cable run I would recommend shielded data cable. Connect the shield to the GND connection at the serial plug end. At the ECU end leave it disconnected.

SOFTWARE:
1)Download and install Winaldl from WinALDL - 160 baud ALDL reader
2) Plug in cable (the engine light should flicker.
3) Select the com port (see below if you have USB)
4) The VN/VP runs the 1227808 ECU
5) Click connect.

USB:
Some usb-> serial converters are a bit mickey-mouse and as this is a non-standard speed you might run into problems. If you already own a serial->usb converter by all means give it a go but if you want to buy one the best ones are based on a FTDI serial converter chip. (For those of you wanting to build a USB version consider that a BIG hint )

Another trick with the USB converter that you will need to be aware of is that WINALDL only looks at the first 4 com ports. Windows may assign a higher com port to your USB converter. To fix this you need to reassign the com port. The instructions are as follows

WIN 98/2000: settings->control_panel->system->hardware
WIN XP: settings->control panel->maintainence ->system->hardware

Then

BOTH: then select device manager this will bring up a display of all your hardware. look for ports (COM & LPT). click on the plus sign next to the icon, this will open up a list of all your ports. The one we are interested in is "USB Serial port (COMx)" if x is between 1 and 4 we are fine. Note that windows will assign a different COMx for each separate usb port on your machine, so if you don't plug the adaptor in the same plug things can get confusing.
If the number is 5 or greater, RIGHT CLICK on USB Serial port (COMx) and select "Properties" then select the "Port settings" tab, then select ADVANCED this will open a menu where you can choose the new COM number. Select something between 1 and 4 and then click OK until you are out of the settings. Close the device manager (don't worry if the COM number is not updated in the menu).

INCAR COMPUTER:
If you are planning on leaving this cable in you car I would suggest putting a bit of black tape over the engine light. The engine light will flicker as the ECU communicates (this is normal). However, this will be very distracting as you drive. You cannot remove the light as it forms part of the circuit and the data link may not work without the lamp in place.

VR/VS/VT/VX/VY Note that this does NOT include the GENIIIs (VT SII onwards). **Note 2. 5.0L V8 owners read the V8 bit.

The circuit I would recommend is attached at the bottom of this page, it is a modification of the techedge circuit but it will work with the 5.0l v8 as well as the V6's. The max232 is a level converter this will change the levels 5V levels from the car to the ones for serial communications (what the computer speaks). As you are using a level converter you will have more luck with non-FTDI (look above in the usb section for the VN/VP) usb->serial converters but I would still recommend them.

Techedge says on their page but I will say it again, be careful about the values of the capacitors that you choose for the max232. Some versions of the chip use different values. Check maxim’s website for the data sheet for the chip you get Analog, Linear, and Mixed-Signal Devices from Maxim/Dallas Semiconductor.

Unlike the VN/VP plug where you can get away without using a pcb, this one things will become a bit more tricky. You can either use Veroboard (YUCK!!), an IC-experimeters board Jaycar Electronics (slightly less yuck) or make your own pcbs.

The Airbag light flashes when I use this on the VX???
Thanks to mike for this one

This is what EFIlive had to say.....


In order to maximise bandwidth on the ALDL data line, EFILive suspends other module's normal communication with the PCM. That causes those modules to request the instrument panel to illuminate their respective warning lamps. All it means is that the module has not been able to communicate with the PCM for some time. Once EFILive stops logging, or is disconnected, normal module communications is resumed. At that point, the modules will request that the instrument panel extinguish the various warning lamps.

Note: the factory scan tool (i.e. Tech 1) usually "simulates" the communications of the suspended modules to prevent warning lamp illumination. EFILive does not do that, instead it uses the full bus bandwidth for high speed logging.

V8 engines
I have found that the techedge circit does not work on some cars, mostly VS and VT V8's. The problem is that the Techedge circuit does not pull the voltage up, it only drops the voltage through the diode, so a high signal is not 'driven'. This is fine for the other cars as the ECU must have a pull up resistor in the circuit. The V8 ECU seems to lack this. The solution is quite easy. On the techedge circuit add two 10K resistors in series (you need 20K and they don't make that size resistor) between the 5V supply and the 8192 baud output pin (the bit that goes to the car). Now when the com port sends a low the voltage is dropped through the diode, a high the diode is open circuit and the volatge is raised through the two resistors.



SOFTWARE:
EFILive: Digital Tools for Onboard Vehicle Electronics
efilive version 4 is what you seek. This program has a limited evaluation trial period.

There is also carbytes which is free but there is only a configuration file for a VR V8. Which didn’t seem to work on the VR I had access to (but neither did efilive)

THE PARTS:
You can get the max232 and the pcb boards (whatever route you choose from Jaycar. I prefer www.futurlec.com as their prices are less but they have no shop you can walk into. Jaycar staff on the whole seem to be more knowledgeable about electronics than Dick Smith’s)

THE PLUG:
Good luck in finding a shop in Australia that sells this plug. Jaycar used to sell it but it has long been discontinued. J1962 OBD2 Connector - OBD-II Connectors: Car Plug is about your best bet now.

GENIII/LS1
Take a look at elmelectronics and download their datasheet for the elm322. Modern GM's (1996 in the USA onwards) speak VPW. The elm322 acts to translate the OBD signals to standard ascii. The result of this is that if you use the elm322 you can let it do all the protocol checking and communicate through any terminal program, like hyperterminal. Of course belting down the 1/4 with your hate typing 0100, 0100 for all its worth is kinda lame. As the output from this chip is well documented a lot of people have written software to graph/log data.
www.elmelectonics.com

If you are going to DIY, you have now left the realms of veroboard. There are places that sell the PCB’s for you to make your own. I might make some if people are interested.

SOFTWARE:
There is a bucket load of software to run these chips.
This is a random selection...

Digimoto OBDII Vehicle Diagnostic Software
pages.infinit.net/jsenk/index.htm
OBD2 Software
ca.geocities.com/t_kolody/OBDSoftware.htm
OnBoardDiagnostics
home.adelphia.net/%7Epjcalinski/RDDTCd.htm
The Cold Front

INCAR COMPUTER:
This includes laptops powered off or conected to anything powered off the car.

There is a trick in the elm322 design that to get the 8 volts needed to talk VPW, the input and output grounds of the PCB can (not always there is another design) be different. This poses a problem for the incar computer as the ground of the laptop is usually conected to the car ground, this will short out the power supply for the elm322 and the chip wont be able to talk to the car.

THE PLUG:
Same plug as above

THE PARTS:
Other than the chip which can only be got from elm electronics everything else is easy to find. Again the transistors are nothing to special. For the NPN's I use BC546/547/547 and the PNP's choose BC556/557/558

The ATMega8 version
For those who are handy with electronics I would suggest this version. The rather expensive ELM chip is replaced by a ATMega8 which is huch cheaper. The code is GPL'd. Go to this site ۝ Mictronics - Michael's Electronic Projects ۝ I did not use his schematic. I used the one on the ELM322 data sheet from ELM Electronics. I have the unit hooled up to a LS1 VU ute's PCM on my desk and as such no smoke has escaped.

LS2 and ALLOYTECH
Thanks to Dr BOB for telling me that these cars run CAN.

The lastest OBDII protocol is CAN (Controller Area Network)

ELM (ELM Electronics) make a chip the elm327 that should interface to the CAN network. Unlike the ELM322 you don't need to worry about isolating the grounds as CAN does not need that weird level shifting trick.

THE PLUG:
See above for details on the OBDII plug

THE SOFTWARE:
At the time of writing (26 Nov) Digimoto lite does not speak to the elm327 (their paid version does). I think that scanmaster II (the demo) is you best bet for the free software. Look at WGSoft.de OBD-II ScanMaster - ScanTool for ELM327, ELM323, ELM320, ELM322, mOByDic (there is english there look to the left)

INCAR COMPUTER:
As there is no silly stuff with the grounds a incar computer should be fine.

Hope this helps

Mike

[OZ38]

VX/VY/VZ V6's
Sorry guys but as best I know (I could be wrong here), no-one has written a configuration file for efilive/carbytes to work with these cars. By rights the VR/VS/VT cable should work, but there is no software around to do the translation.

Hope this helps

Mike

Well that leaves me waiting for a very bright spark to offer the software. Could be waiting a very long time by the sounds of it.
Maybe I should look into the Kalmaker ECU conversion again

[michaelw]

Well that leaves me waiting for a very bright spark to offer the software. Could be waiting a very long time by the sounds of it.
Maybe I should look into the Kalmaker ECU conversion again

What about the megasquirt and the like. I'd be interested to hear what peoples experiences with the build it yourself ecus are like. I wonder who they fit in with modern car networks where the modules talk to each other?

Mike

[OZ38]

Using cable on a VY ? Off Topic

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Gidday this question is for Michael W. and Doctor Bob.
If I was to plug this cable into my VY series I ASDL plug under the dash from my laptop. With the engine stopped or running or then starting the engine. Can I do any damage or hurt anything ? I've been downloading different programs off the net to see if I can get a scan off the engine ( want a full diagnostic read out ) Going to try Digimoto,Diagnose 3.0 and EFIlive etc to see what happens. Eventually wanting to find one that may work with the S/C PCM that will be fitted with the engine swap. But for now just want to look around to learn a bit.

Cheers

Deek
__________________
Aussie Aussie Aussie, Oi Oi Oi .


Yesterday, 01:21 PM
michaelw Ride: VN S
Location: SW Sydney
Posts: 237

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Digimoto, Diagnose and efilive V5/6/7 speak OBDII. The only commodores that use OBDII as far as I know are the GENIII's

The VT cable listed here speaks 8192 baud. As best I know the VY V6 uses the 8192 baud system but I have no idea what the codes are. My suggestion is to look into carbytes or efilive V4. If you know what you are doing you should be able to decipher the info. I doubt you will kill your car. But I am not betting my left one on it .

The VT V6 configuration file would be a good place to start. Plug the cable in with the engine not running (but ignition in 'on') and select aldl->detect chatter. This should give you a starting point to see if efilive V4 can even understand or hear any communication.

Also I have started a thread in the electrical section about generic ECU stuff. Questions not related to "Crazy Mikes Wonder Cables" should best be directed there, as much of this stuff is probably of interest to people who already have or can build their own. http://forums.justcommodores.com.au...ead.php?t=19665

Mike

[OZ38]

So from the above info I would only have a little hope from Efilive V4 if any is that what your saying Mike ?
Also I've not heard of Megasquirt so can I have more info please.

Deek

[OZ38]

Another question.
Can you get EFIlive V4 as freeware or Carbytes as I don't see it available through a google search ?

[michaelw]

Megasquirt is a build it yourself drop in replacement for the ecu. It looks very interesting but I have no experience with one. The advantage (as with all things open source) is that you know exactly what is going on and are not locked into any one supplier.
http://www.bgsoflex.com/megasquirt.html

http://www.msefi.com/

www.efilive.com click on downloads, then efilive v4. V4 and carbytes live on this page.

Mike

[OZ38]

Whenever I tried to download Carbytes V2 it gets to 38% then stops with a explorer message " server was reset " i tried three times but got to the same point approximately each time. i'm on dial up but that should make any difference should it ? Any answers to this ( I know it's off topic and I'm sorry about that) ?

This has happened to me before when trying to download things.

[michaelw]

This has happened to me before when trying to download things.

Try another browser.

Mike

[OZ38]

Got it sorted, downloaded Flashget first then no problems after that.
Is EFIlive V4 only available in evaluation of 1-2 months or licenced version with no freeware ?

[breast69au]

after reading all of this has anybody tried on the VY Commodore??? and had success???

[OZ38]

after reading all of this has anybody tried on the VY Commodore??? and had success???

I haven't been game to try as I can't afford for the car to develope any problems from trying.
Only mode of transport and up in the bush.


Mike I tried the usb cable on a VS of a friends with the carbytes download.
Couldn't seem to get any thing back ? I was probably doing it all wrong but I turned the ignition on with engine not running, then plugged it in and selected chatter. Nothing happen.
Any suggestions ?

[michaelw]

If it was a V8, I too have had some issues with the 8's. I am looking at a slightly different circuit, that should do the job. I keep youse posted on what I find.

Mike

[OZ38]

If it was a V8, I too have had some issues with the 8's. I am looking at a slightly different circuit, that should do the job. I keep youse posted on what I find.

Mike

No It was a ecotec V6, but like I say I've never tried this stuff before so highly possible that it is a fault of something I am doing (or not doing). Thinking about hiring a VY from a hire company and trying it ha ha. ( *honest it just died for no reason, bloody hire cars, send me another one*)

[michaelw]

Ahh will the reason for carbytes not working is that the definition file (there is only one) is for a VS V8. Try efilive v4.

Mike

[OZ38]

Ahh will the reason for carbytes not working is that the definition file (there is only one) is for a VS V8. Try efilive v4.

Mike

ahh thanks Mike, see I said I didn't know what I was doing so theres the proof.

[michaelw]

Look up. I have added information on the ALLOYTECH and LS2.

Mike

[michaelw]

NEW INFORMATION: VS/VT V8's. I have added some information about these ecus that should solve comms problems.

Mike

[brettless]

I have purchased a elm5 scantool which scans 9 obd2 protocols but it will not communicate with the VX 5.7 litre and have also tried it on a 2003 model Vu ss commodore ute and had the same result.I have been told and now tend to believe that these models are not obd2 compliant although aussie commodores use the obd2 type plug.The unit will work on a 2004 model ford so the unit does work.There is a lot of info out there but be careful as a lot comes from the states and does not appear to apply with our vehicles.
Cheers

[michaelw]

Welcome to the madhouse brett, I have sold elm322 units to a few people on this forum and on ebay (at least one owned a VX 5.7) and they have worked.

Do you happen to know what chip the scantool is running, I guess it is the elm327? and also was your computer in anyway connected to the car's electrical system (obviously other than the scan tool), for example an inverter or lcd screen.

Mike

[brettless]

I believe the unit has the new elm327 chip.the laptop was under its own power at time of testing and no inverter was used.The unit did however work on a 2004 ford

[michaelw]

As you have already got one of theirs, i would try and get it replaced for one based on the elm322. I am surprised that the 327 does not work for the genIII as acording to the data sheets it *should* but I haven't played around with that chip yet.

Mike

[HDT_aero]

just so you know guys 1/2 watt 10k resistors work fine aswell and are easier to come across

[brettless]

Hi , I have sent a few emails of to the supplier to get more info but there seems to be a lot of conflicting information im getting.I have a manual for the vehicle i have and it does suggest 2000 and on models are obd2 compliant and i have sent that extract to them.Shall see how i go now.

[brettless]

Hi there, I got that Elm 327 chip to communicate with my car 2 day.I retired it on a ford 2004 and was able to get sensor data,then tried it on a Avantra 2004 5.7litre and it seemed to have a bit of a hiccup then bingo got sensor data out of it.So i tried it again on my Vx 5.7 litre and bingo i could get sensor data,very strange but thing somehow scanning the Avantra jolted it into action,maybe the elm Gm protcol sensing a bit dicky,will see how it goes