OBD1.5 is an "enhanced" version of OBDI. It has some of the capabilities of OBDII, but not all. DTC's are 5 character, instead of two on OBDI. It uses the same style connector as OBDII so any OBDII scan tool will connect to it. The scan tool needs to communicate using the protocol that the PCM was programmed with, (they must speak the same language). If your scan tool shows any data at all when you connect it, the correct protocol is available in the scan tool, (there are several different protocols used by the manufacturers).

Here are a few things you will not be able to view:
B2S1 oxygen sensor, not equipped.
Bank 2 fuel trims, it only has bank one.
MAF sensor, not equipped.

Your PCM does control shift points, so it should provide DTC's for it if there's a problem. The question, is can your scan tool retrieve them.

 

yea my scan tool should be able to read tranny codes. I also own a 97 bravada and it had a code po1870 which I was able to read with my scan tool. I had a low mile used tranny put in that one though. but its weird with my 95 that the po1870 code never set. and it also has the same style computer on the fender well that my bravada has.

 

The 97 Bravada is fully OBDII compliant, and uses a very common protocol. If the scan tool has the OBDII style connector, it will automaticlly detect the protocol and communicate, no problem.

P1870 is slipage, stuck spool valves will not set that DTC. When the valves stick, the solenoids could be working fine, in which case, the PCM would not recognize them as a problem. Somewhere around here there's a GM TSB that addresses the issue. There are also aftermarket companies that make repair kits for the valve body. Entails drilling the bores and installing bushings. From what I hear, (no first hand experience) if done correctly, it fixes the problem.

 

thanks for all the info

 

You're welcome. Just a little food for thought. It helps doing your homework before making a decision.