OBS II conversion

[ace_ga]

hey guys, i have a 95 Grand am GT with the OBD 1.5 system in it. is there a way i can convert to the OBD II system used in 96 and later models? if so what all do i need and what is involved. i want to get one of Germ's turbo kits when they are realeased and i want to be able to tune it with the DHP Power tuner. so can you guys please help me out. thanks

[bszopi]

RE: OBS II conversion

You'll need the PCM, the engine harness and probably the inside harness to the PCM. You might also need the bulkhead connectors. And you'll need wiring diagrams for your car as well as the donor car.

[eliteweapons]

Yeah I was looking at that too but way too much work to change all that out for me.

[Azrael]

When I compared a service manual for a 94-95 V6 GA with the 96 3100 OBDII wiring chart here, I found almost all the wires were identicle. Just a few odds and ends were added/changed (like security features) but it might be possible to disable/change them in powertuner. PCM connectors are also different obviously.

Good luck with the project! We can't let the new GA's hog all the fun.

[Erich]

I did the conversion on a 1995 Beretta using a 1996 Harness.

The ABS system changed in 1996. You may also have a problem with the cluster. I am awaiting 1996 DHP tools so i can make the adjustments and delete things. The only problem i had was with the rear O2 other than my brakes.

[eliteweapons]

crap!

I just found out that no modifications at all can be done to my factory 1995 beretta computer. I am going to have to change to a newer system. Any tips you have will be a great help Erich.

[Rhedalert]

RE: crap!

What do you do regarding the EVAP system? The OBD2 computers need a sensor to detect pressure in the tank, correct?

[eliteweapons]

I don't know.ObdII is new to me so any help here is appreciated.

[ace_ga]

well is there any way for me to be able to tune my car and run it safely with the stage 2 turbo kit that i plan to get from germ? i know Matt95GT supercharged his 95 but i cant remember what he used to tune it.

[Manitcor]

if your running ODB1.5 there is one place that can burn a PROM chip for you but its limited in what it does and is overly expensive.

For 95 cars upgrading to ODBII isisnt too bad however in 1995 GM had about 2 or 3 different versions of various harness connectors and some models had 2 different versions of the 95 setup (early 95 and late 95).

This swap can be done, you wont need the internal harness however you will need to move some pins around on your body connector on the new harness to get everything to work correctly. You will also need to change out some sensors and such.

Im working on a guide for the 95 MC LS which should help anyone doing this swap however there are variations between each 95 car so research will need to be done to determine your excat siutation.

Go for an ODBII harness for the same car you have just go up to the 96 model year. Once your ODBII you can use any of the main tuning packages out there to tune for what ever you are doing. The prep and setup for the swap can take a few weeks to track everything down and get the new harness ready. The swap itself can normally be done in about 4-5 hours and you wont need to remove the engine or the trans.

I just got my tuned PCM in and I can defintaly say the extra work to get a modern PCM in was well worth it.

[OldSkoolGP]

Check back with me this winter. I'm switching my Grand Prix over to OBD II.

[eliteweapons]

Hey Manticor. Do you have to replace the under dash harness as well when you go from the 95 to the 96 or just the engine harness and computer?

[Erich]

W bodies and L bodies have different amounts of work to get this to work. I have done a 1995 beretta OBDI to OBDII.

We found the differences between 1996 and 1995 to not play a difference in the wiring dash harness. I am also selling a complete OBDII setup for a Beretta/Corsica. I did find that you may want to upgrade the ABS computer and pump/solenoid assemblies to the 1996+ style.

The Beretta harness ONLY work in a Beretta for direct swap.

Here is what to be swapped.

engine harness w/all plugs to firewall
knock sensor to 96+
injector harness (plugs are different and 3 prong temp sensor)
3 prong temp sensor

There are some minor issues with purge solenoid. We did not use rear O2 sensor and you have to swap or delete your EGR.
These 3 mentioned issues can be deleted with the DHP tuner that is NOW available from Germ & DPP.

[EspanolaGuitarista]

What about California. Do it right or don't do it at all. I'll get real upset if I can't play too.