Can anyone here confirm that the '97 Camaro Z28 uses the ISO protocol in
addition to VPW? I'm getting a OBD II code reader and I'd rather get the
ISO version than the VPW, but it needs to work on my Camaro. This site
lists my car as the only Chevrolet to support ISO, all others are VPW:
However, this more professional looking site doesn't mention it:
I'd like to be sure so I don't buy something that doesn't work.
I dont know offhand what the Camaro uses, but I had some comments:
Although cars can speak multiple protocols internally, they are supposed to
answer OBD-II on one (and ONLY one) protocol, per various regulations. So if
the car is compliant, you won't be getting OBD-II response on multiple
One solution is to get a PassThru (J2534) compliant scantool supporting all
protocols, and use SAE J1699 for auto-discovery. The J1699 document
specifies a CARB/OBD-II compliance test; it involves opening each protocol
in succession, to determine which one the vehicle uses. Although you must
buy the SAE's J1699 document, there's a free open-source implementation of
the spec available at http://j1699-3.sourceforge.net
This requires a PassThru (J2534) compliant scantool, which hooks your laptop
up to the car. It's more expensive than an average $40 codereader, but for
an independent garage or a car enthusiast it's something worth considering.
That way you can programmatically reflash, calibrate, and coderead for
J1850VPW, J1850PWM, CAN, ISO 15765, ISO 9141, Chrysler SCI, and other
protocols using just one device.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.