This article focuses on 1994 - 1995 GM and OBD

When GM anticipated the 1996 OBD2 requirements they began implementing these changes in 1994 and 1995 on some models. These changes in some cases included a connection port that looked like the 1996 OBD2 port, but is NOT. A scanner that connects to OBD2 vehicles WILL NOT work on these vehicles even though the cable will plug in. Also, the early GM OBD systems could be have the codes retrieved with a simple plug-in code reader or even by jumping the terminals with a paper clip, not so here. A scanner that could read codes on the earlier ALDL system will not work here, even though the cable connects to a similar plug.

I came across this on my 1995 Jimmy. I had a CEL and wanted to scan it for codes. It had an OBD2 style connector but my OBD2 scanner showed a communication error. Thus began the education process. I searched the Internet far and wide for an answer and their was little. I found information on the OBD change but little on what scanner would work. Many scanners would advertise that they worked on early and late GM OBD systems, but they did not. I finally found one that DOES work on all GM systems, including the '94-'95. If you think you have found a scanner that works on these vehicles, be sure you get it in writing that you can return if for a full refund if it does not work on your vehicle.

I found this on eBay, about $250 at the time. Check Amazon as well. I am sure by now that others are available however, these vehicles are getting old and nobody is going to be supporting them much longer. Professional scanners like Snap-On and MAC Tools will also have older scanners that can do this. You could search eBay for a good used scanner.

GM 1994 - 1995 OBD

Actron CP9145

A standard OBD2 connection port

The 1994 - 1995 GM OBD port MAY look like this, an OBD2 port, but it WILL not work with an OBD2 scanner. Earlier systems would let you use a paper clip to get codes, this will not!

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