OBD2 conversion Rev.B - L27
Thread Starter
Senior Member
True Car Nut
Joined: Aug 2004
Posts: 3,067
Likes: 1
From: In your garage, swipin' da lug nutz

Call me a gluton for punishment. Call me crazy...I don't care. over the last 6 months, more money than I care to admit was tied up in the 93 SSEi, and most of that money was due to the PCM conversion (HP Tuner, several PCMS, etc.). Money that I will never see again...so I might as well put it to good use.
It'* a known fact that the 94/95 PCMs work great when they are good...but when they are bad, they are a major PITA. And very hard to come across a good one in the JY. When I did the 1993, that harness was made from scratch, and although it worked well enough, it was far from the plug-n-play setup I initially intended it to be. But the 94-95s are a different story.
Aside from running new wiring for MAP, AC pressure, and the EVAP flow switch (a total of 8 wires), and figuring out the cruise control (that was next on the project list), the conversion on the 94/95 models should be MUCH easier to do. Taking lessons learned from my first attempt, here is the outlay for "Revision Bravo" :
1) PCM will be located in the cabin, underneath the stereo.
2) Connectors from a 94/95 PCM will be scuttled from it, and they will be soldered onto the corresponding OBD2 PCM wires. The harness itself should be no more than 3.5 feet, to allow for service loop.
3) Non-shared wiring will be bundled up, and ran through a grommet hole to the engine bay. This includes the cruise control, AC, MAP sensor, and any others that might crop up.
This system, unlike the first one, will be geared for plug and play conversions, and should be completed in an afternoon. The system works, as I've already proven. Now, it'* going to be controlling a stable platform (unmodded and well-cared for L27) instead of a Frankensteined engine. When i start on this project, it will take a matter of weeks, not months, to accomplish, since the research has already been done. From a performance standpoint, I realize I won't gain much...if any at all. This is more for replacing the funky OBD1.5 system and going with a standard OBD2 setup.
I'd like some input from you guys...if this kit *were* to be produceable, what would you like to see?
It'* a known fact that the 94/95 PCMs work great when they are good...but when they are bad, they are a major PITA. And very hard to come across a good one in the JY. When I did the 1993, that harness was made from scratch, and although it worked well enough, it was far from the plug-n-play setup I initially intended it to be. But the 94-95s are a different story.
Aside from running new wiring for MAP, AC pressure, and the EVAP flow switch (a total of 8 wires), and figuring out the cruise control (that was next on the project list), the conversion on the 94/95 models should be MUCH easier to do. Taking lessons learned from my first attempt, here is the outlay for "Revision Bravo" :
1) PCM will be located in the cabin, underneath the stereo.
2) Connectors from a 94/95 PCM will be scuttled from it, and they will be soldered onto the corresponding OBD2 PCM wires. The harness itself should be no more than 3.5 feet, to allow for service loop.
3) Non-shared wiring will be bundled up, and ran through a grommet hole to the engine bay. This includes the cruise control, AC, MAP sensor, and any others that might crop up.
This system, unlike the first one, will be geared for plug and play conversions, and should be completed in an afternoon. The system works, as I've already proven. Now, it'* going to be controlling a stable platform (unmodded and well-cared for L27) instead of a Frankensteined engine. When i start on this project, it will take a matter of weeks, not months, to accomplish, since the research has already been done. From a performance standpoint, I realize I won't gain much...if any at all. This is more for replacing the funky OBD1.5 system and going with a standard OBD2 setup.
I'd like some input from you guys...if this kit *were* to be produceable, what would you like to see?
Thread Starter
Senior Member
True Car Nut
Joined: Aug 2004
Posts: 3,067
Likes: 1
From: In your garage, swipin' da lug nutz

I was looking at the SSE yesterday after work (just did the AL7 conversion to it!!!), and there really isn't any room under the dash for the 1997 module...though I am betting the 1998-up modules could. Since budget is a prime factor, I gotta stick with the 1997 setup. And since I do NOT want to stick the PCM in the engine bay (as it would mean having to lose or relocate the airride pump and the headlight washer bottle), the next best place is in the trunk. The only issue I have in doing this, is the fact that the wire resistance is going to be greater, making response times slower.
Rivieras had their PCMs mounted underneath the seat, so maybe the distance between the PCM and the engine isn't too bad afterall in terms of operation efficiency.
Rivieras had their PCMs mounted underneath the seat, so maybe the distance between the PCM and the engine isn't too bad afterall in terms of operation efficiency.
Thread Starter
Senior Member
True Car Nut
Joined: Aug 2004
Posts: 3,067
Likes: 1
From: In your garage, swipin' da lug nutz

Nope...no room there at all for the larger PCM. It COULD fit there actually, but I want it to be invisible. No such luck there...it will fit, but can also be seen. If this were the new-style PCM, it could be hidden somewhat easier.
Looking like the trunk will be the best location...passenger side, all the way forward, butting up against the seatback. I estimate I will need about 7-8 feet of harnesswork to patch the PCM with the 94/95 connectors.
The OBD2 connector is going to be located in the center console I think, or maybe the glovebox. It'* a pain in the assets to try to plug the tuner in where the connector is at now.
Running power to the PCM will be a toss-up between using the factory fusebox or running a seperate power buss on the opposite side of the car, coming from an additional fusebox I already have. Grounds are a non-issue.
Looking like the trunk will be the best location...passenger side, all the way forward, butting up against the seatback. I estimate I will need about 7-8 feet of harnesswork to patch the PCM with the 94/95 connectors.
The OBD2 connector is going to be located in the center console I think, or maybe the glovebox. It'* a pain in the assets to try to plug the tuner in where the connector is at now.
Running power to the PCM will be a toss-up between using the factory fusebox or running a seperate power buss on the opposite side of the car, coming from an additional fusebox I already have. Grounds are a non-issue.
Thread Starter
Senior Member
True Car Nut
Joined: Aug 2004
Posts: 3,067
Likes: 1
From: In your garage, swipin' da lug nutz

Considering that too. If I didn't have dual power seats, it would go under the passenger side.
I'll have to take a look at the passenger side cavern that houses all the electronics. The SSE came stripped in regards to electrical doodads, so I may have some room there to work with.
I'll have to take a look at the passenger side cavern that houses all the electronics. The SSE came stripped in regards to electrical doodads, so I may have some room there to work with.
Thread Starter
Senior Member
True Car Nut
Joined: Aug 2004
Posts: 3,067
Likes: 1
From: In your garage, swipin' da lug nutz

Not really. It keeps my CDs from going everywhere
Plus, there is an A/C vent that runs underneath of it. Just the storage room offered by the console isn't big enough.
Plus, there is an A/C vent that runs underneath of it. Just the storage room offered by the console isn't big enough.


