You don't. Your vehicle only supports OBD1 protocol. However, there is a
bright spot. On most if not all GM vehicles with OBD1, you can short two
terminals in the ALDL connector (look under the dash and online for
directions) to get the codes sent to you by way of the "service engine"
light. Each code (starting with "12" for "system OK") is relayed a single
digit at a time, and repeated three times on top of that.
If your vehicle has a *factory installed* electric cooling fan, it may also
run at the same time. This is not a problem.
That is because OBD2 only applies to 1996 and newer vehicles in the US...as
well as a very few 94 and 95 model years (or so I'm told--never seen one).
These won't work with your vehicle unless you use a hammer to insert the
connector and then nothing will work at all.
On Sat, 5 Jun 2010 00:18:50 -0500, "William R. Walsh"
Actually a bit of trivia. Code 12 is actually "missing engine speed
signal" which indicates the engine is not running. The reason it
appears (first) is that it is the lowest numbered DTC. It can happen
while the engine is running, too. (Yes, I've seen and had to repair
The best is WinALDL software for a PC, then in addition to codes, you can
also get "live data". Get that here...
The above software is free, but you need an ALDL cable (ALDL to serial).
Instructions for making your own or buy one here...
Then if you have a laptop computer without a "serial port", you need a USB
to Serial cable and many sold in stores don't work right. The following
works fine and not too expensive...
Parallax USB to Serial (RS-232) Adapter with Cable...
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