Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

[General] [VR/VS/VT/VX/VY/VZ] Everything to know about ALDL Diagnostic Cables

TazzI

Envyous Customs
Joined
May 24, 2011
Messages
1,077
Reaction score
366
Points
83
Location
Western Australia
Website
www.envyouscustoms.com
Members Ride
Holden VE SS Ute
Exactly. Unless the ALDL cable has been specifically designed for 12V signal levels, at the very best, you'd be injecting current into the static protection diodes of the UART-USB bridge chip's RX input via some series resistor, potentially overstressing it and even your PC. You'd better check with the vendor first to see it is safe to do this.

The other risk, which is easily overlooked (even by the vendor), is that the transistor on the TX part of the circuit will not be designed to drive the surge (cold) current of the CEL bulb. So if you accidentally run software that tries to transmit to the ALDL, you'll likely blow the TX circuitry, which may then impact on the RX circuitry (since they are tied together on a common data line), so the whole thing then doesn't work.

A purpose-designed ALDL cable for VN/VP will be designed for 12V signal levels and won't have TX circuitry to blow up. (At the moment, I'm considering designing and making such a cable to sell on eBay, but I'm not sure if there's enough demand to justify the effort.)

Joe.
To overcome the 12v signal, Some simple work with transistors would be needed for reading, or voltage divider to bring it down to slightly under 5v for safety. I dont think there is really any need, or ability to TX on VN/VP. Since they output a diagnostic message every 1200ms (something like that). Not a whole heap of great information comes from it either. So the whole TX part can be left completely out.
But due to this fact that there is next to no good information to pull out of the VN commodores, It doesnt seem there is many people that even want a diagnostic cable. Can see the data below that a VN outputs.. its really not much at all!



All newer commodores have multiple modules that can have information requested or even programmed.

Iv got a prototype on the bench currently waiting to be tested for the VN/VP. Just waiting for the VN ecu I purchased (almost 2weeks ago now.. *sigh*) to rock up for testing and designing up-to-date software for viewing the data rather than the old school winaldl application.
 

Novacula

New Member
Joined
Feb 15, 2015
Messages
22
Reaction score
0
Points
0
Age
42
Location
Cairns
Members Ride
Statesman
Hey all, been reading the thread and have a question. Am I correct in assuming my 2002 V6 WH Statesman Series II is based on the VX engine? And as such only communicates via the aldl cable?
 

TazzI

Envyous Customs
Joined
May 24, 2011
Messages
1,077
Reaction score
366
Points
83
Location
Western Australia
Website
www.envyouscustoms.com
Members Ride
Holden VE SS Ute
Hey all, been reading the thread and have a question. Am I correct in assuming my 2002 V6 WH Statesman Series II is based on the VX engine? And as such only communicates via the aldl cable?
That is correct!
 

mrrulke

New Member
Joined
Apr 2, 2015
Messages
1
Reaction score
0
Points
0
Age
41
Location
Australia
Members Ride
Holden Gemini VR V6
i have a VR v6 in my gemini. did it a long time ago. finally got my self a cable to check stuff out with it, as she is getting a little old and want to make sure she is ok. And also I have time to work on her.
For the life of me i cant find the connector. I think they turned it into a plug in one. so i need to wire up a new one. i bought my self an extension cable OBD2 Connector 16 PIN Male TO Female Extension ELM327 Diagnostic CAR Cable Flat | eBay Can you tell me what colors go where so i can wire up new one.
 

j_ds_au

New Member
Joined
Feb 14, 2015
Messages
18
Reaction score
1
Points
3
Location
Sydney
Members Ride
VS T4
Hi TazzI,

Here's something weird I came across in an old thread : https://forums.justcommodores.com.au/threads/diy-ecu-scantools-data-cables.19665

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.
Have you heard of such a thing before? I can't find any other source for this information (misinformation?) and haven't had any such issues from my own customers with such cars.

If this were true, it would mean these cars have a non-functional ALDL bus, and that just makes no sense.

Joe.
 

TazzI

Envyous Customs
Joined
May 24, 2011
Messages
1,077
Reaction score
366
Points
83
Location
Western Australia
Website
www.envyouscustoms.com
Members Ride
Holden VE SS Ute
Hi TazzI,

Here's something weird I came across in an old thread : https://forums.justcommodores.com.au/threads/diy-ecu-scantools-data-cables.19665



Have you heard of such a thing before? I can't find any other source for this information (misinformation?) and haven't had any such issues from my own customers with such cars.

If this were true, it would mean these cars have a non-functional ALDL bus, and that just makes no sense.

Joe.
Gday Joe,

No I cant come up with any information about that either. I have VS and VT ecus on bench right here and they all float high with not in use as expected to be seen on all ALDL bus driven Holden commodores.

It more sounds like whatever schematic was being used there was actually holding the bus low preventing any communication.
 

j_ds_au

New Member
Joined
Feb 14, 2015
Messages
18
Reaction score
1
Points
3
Location
Sydney
Members Ride
VS T4
Gday Joe,

No I cant come up with any information about that either. I have VS and VT ecus on bench right here and they all float high with not in use as expected to be seen on all ALDL bus driven Holden commodores.

It more sounds like whatever schematic was being used there was actually holding the bus low preventing any communication.
Thanks, TazzI.

Yeah, it's odd that this supposed problem isn't mentioned anywhere else that I can find.

The circuit mention is the "Techedge" circuit, and this guy used to make a USB adaptation of their circuit. However, something holding down the bus doesn't explain this either, since the supposed solution for this supposed problem was to add a 20k pull-up resistor (that's a pretty weak pull-up). As read, it couldn't be 18k or 20k, which are far more common, so you supposedly needed two 10k resistors in series. Bizarre.

OK, unless evidence to the contrary turns up, I'm going to call this as misinformation.

Joe.
 

TazzI

Envyous Customs
Joined
May 24, 2011
Messages
1,077
Reaction score
366
Points
83
Location
Western Australia
Website
www.envyouscustoms.com
Members Ride
Holden VE SS Ute
Thanks, TazzI.

Yeah, it's odd that this supposed problem isn't mentioned anywhere else that I can find.

The circuit mention is the "Techedge" circuit, and this guy used to make a USB adaptation of their circuit. However, something holding down the bus doesn't explain this either, since the supposed solution for this supposed problem was to add a 20k pull-up resistor (that's a pretty weak pull-up). As read, it couldn't be 18k or 20k, which are far more common, so you supposedly needed two 10k resistors in series. Bizarre.

OK, unless evidence to the contrary turns up, I'm going to call this as misinformation.

Joe.
Yep, another example of "iffy" information floating on the web!
 

Dirou

New Member
Joined
Jan 21, 2008
Messages
6
Reaction score
0
Points
1
Age
59
Location
Newcastle
Members Ride
VS II "S" ute auto
AED is great software however the serial number becomes invalid anytime you want to do a clean install on your computer. Very annoying and a bit penny pinching in my opinion. I don't have this problem with other software I purchase !
Brian
 

losh1971

Well-Known Member
Joined
Jan 17, 2010
Messages
12,295
Reaction score
5,578
Points
113
Location
North Tas
Members Ride
The Bus
Yeah it is a tad annoying. I bought a new laptop and need the software for my new one. Old lappy no longer works and that's where the product key was used. I have to buy a new key but it's not real cheap, so I haven't bought one yet. If it was say 25 - 30 bucks I'd have bought one months ago.
 
Top