bigbadwhopper

My daughters car says it is OBD1 on the emission sticker, but has the OBD2 plug. I know this was a tranition year (95) between the two systems, but I can't figure out how to read the codes. I know an OBD2 reader won't work and I can't jump the two pins. Anybody know Of a code reader that will work?
Thanks

bigbadwhopper

Thanks for the response, but I tried with a OBD2 scanner (thats what the plug is for) and I juse get error since the system is OBD1. I heard The dealer has a scanner that will work, but was hoping for a cheaper route.

95SonomaDriver

I have a 1995 GMC Sonoma that has an OBD2 port. I have tried several "over the counter" OBD2 scanners on it but none of them have worked. They all will draw power from the connection but none of them would communicate with the computer. I found fairly nice scanner from Craftsman on clearance last night and decided to give it a try. Same result (although this one actually had a display where I could see it attempting the various protocals, kinda neat). This scanner actually had a tech support number so I gave them a call and was told there is a KNOWN and fairly common problem with various 1994 and 1995 General Motors vehicles: OBD1 computers but OBD2 connection ports. A mechanic friend (who unfortunately lives 3 hours away) has a scanner made by SnapOn that will connect and read. I'm assuming that the SnapOn scanner somehow detects what is happening on each pin and adjusts accordingly on it's own.

I'll add that the emissions sticker on my truck does NOT have the OBD2 certification marking. Oddly enough, I assumed an OBD2 port meant I had an OBD2 computer...Silly me.

I'm planning to get an OBD2 and OBD1 cables along with a diagram of the pinouts and hack them together then connect to an OBD1 compatible scanner or find a scanner that already accounts for this stupidity.

I'm also wondering if this merits a Class Action lawsuit since they paired up incompatible hardwares (the on board computer and the port you have to use to connect and diagnose it). This is the sort of thing that "heards" owners into "Stealership" repair shops (where they have more sophisticated scanners that can get around the manufacturing f-up) instead of being able to do the work yourself or take it to a less expensive shop. To me this is either an intentional bad design or a case of running out of correct computers or correct wiring harnesses and simply sticking something in that would still work without regard to the diagnostic problems it would cause consumers (and probably a lot of repair shops).

masbro

I have a 1995 Chev Blazer that has a OB2 plug but is a OB1 system
almost all sites I have visited including here tell you you can manualy read the codes on a 12 pin connector Pin A+B for 95 chev OB1 but the 95 chev uses a 16 pin so how do you read the code on this there are 6 connections pin 5 is ground I am one of the suckers that bought a 3140 OB1/OB2 Innova Scann Tools was told it would work (BULL) So can someone who is knows can tell me what pins I need to jumper to read the codes
Thanks
Masbro

markspark61

markspark61, Here, also went to innova, but they sold me a obd 1 #3123 and it seems to work fine , good luck

masbro

Thanks for the reply
I already purchased a 3140 OB1/OB2 Innova Scann Tools at 375.00
was told from merchant that this would work well it does not work with
this OB1 95 chev. there is no way I would invest another dime in any Innova item since their Tech department did not care or had any solution
at this point I just wrote them off at scammers. And will look to dump this item for newer cars??
Masbro

baer1959

I have a similar problem . My wife has a 95 Jimmy with a 16n pin obd2 port and a obd2 computer on the fender well, but it is still obd1. My question is since it appears to have all the componants for obd2 is it possible to flash the computer to upgrade it to be fully obd2 compliant?

sledge.impy

I've never heard of that. Might want to check with some Jimmy specific forum.

Look at the last picture here. This might work in your situation.

OBD and OBD reader question - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

T4Turtle

The Actron CP9185 has OBD1 for GM, Ford Chrysler (including Chrysler Jeep) and it works on my sons 1995 Firebird with the same OBD1 PCM and OBD2 connector. The problem is GM ran their own pin out for the OBD1 computer and most tools do not have this capability to switch for this pin arrangement.

No need to buy the OBD1 cable of course.

Also a AutoXray AX6000 will work, it comes with Domestic OBD1 cables and regular OBD2. Then there is a special blue OBD2 shaped connector just for these GM vehicles.

sledge.impy

I've used my diacomm with success.

Innova 3120 appears to be an issue.


Question 1994 formula dtc codes help me please - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums