Differences between OBDII and ALDL Communication

[TazzI]

Alright so Iv been contacted a couple times now regarding communication with VY/VZ commodores. Just thought I should get it cleared up as I am started to confuse my self!

SO an ALDL cable is used for communication with VY commodores and below BUT I personally know for sure that a ALDL cable will work with a VZ commodore when communicating with BCM,Cluster,SRS module, Radio.

In saying that, ELM cables are used for OBDII communication right? Been informed twice now that they are able to communicate with VY/VZ BCM,Clusters,SRS modules. So can an ELM also grab the ALDL communication as well?

Can anyone shed some light or let me know if this is right? Or what the differences are in the two communications?

Could be that they have a costly diagnostic cable although seems that they grabbed cheapy off ebay. Iv also noticed "ALDL" cables which state to be used for Holdens being sold on ebay which look IDENTICAL to some OBD/OBD2 cables on a chinese store which are made for old BMW's or something.

Cheers,
Tazzi.

[jezzab]

As you know, ALDL is basically just serial.

All the modules from VN-VZ for SRS, Airbag, Cluster etc all communicate with ALDL which is the old school CLASS-2 (GM-LAN) Network. The later models like VE use a single wire low speed CAN communications for GMLAN.

If the cable can do ALDL then its fine. But the ELM327 etc ive used dont. Most ALDL cables are just a USB to Serial with a transistor.

Dont forget the ELM type cases you can buy

[TazzI]

Good, Im not going nuts then.I guess they could have grabbed an elm case and cable and chucked in a different circuit board.

So ALDL can also be known as OBD1 communication as well right, assuming its the later communication using bidirectional single wire communication. Iv seen a few elm devices that do both OBD2 and OBD1 so that could be what there using?.
Either way, may just grab one to see if it does work as its a cheap alternative to some of the ALDL cables sold on ebay.

[gruntly69]

I'd love to chip in with something useful but not 100% on all communications, I'm fairly sure my hp tuner dongle connects to both obd1 & obd2 vehicles?

[jezzab]

I'd love to chip in with something useful but not 100% on all communications, I'm fairly sure my hp tuner dongle connects to both obd1 & obd2 vehicles?

Only OBDII mate. It wont do ALDL (OBDI)

ISO15765 HSCAN (VZ 6.0L)
J1850VPW (VT-VZ LS1)
J1850PWM (FORD)

EFILive V2 is capable but they have yet to finished the software and firmware

[gruntly69]

Is there a descent program out there that will sniff the OBD2 using an ELM327 v1.5?

There is quite a few programs that come with the device but most seem to be to check fault codes & what not!

[jezzab]

What protocol? Most will do generic PIDs but not extended PID as they are proprietary and they usually charge for the privelllage.

ScanXL comes to mind and is muli protocol and works with the ELM

[gruntly69]

Thanks Jezza,

Not sure what protocol, just wanted to listen in on a few cars & devices while my scan tool & other devices are in action to see how it all works!

Thanks again!

[jezzab]

Just use a terminal with it and ATMA. Will show a lot more then a scan tool will