OBDI to OBDII Swap
07-25-2008, 06:31 PM
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OBDI to OBDII Swap I have 95 and 96 Corvettes. The 96 is about to undergo a major change with a supercharged 383 and Ive decided to tune with JET's dynamic spectrum tuner. After the swap is complete, I'll be making some modifications and eventually swapping in a stronger engine into the 95. I've heard of people swapping from 96 to 95 ECM's (for good reason, I'm sure), but I am thinking of going the other direction. I have an extra 96 computer (and harness) and would not have to buy new software or another license with the JET Software. Are there any wiring changes needed to swap from the OBDI to the OBDII computer?
Last edited by gsdave; 07-25-2008 at 08:30 PM.
07-25-2008, 08:34 PM
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Sorry, I put my info in parenthesis in the wrong place--editted the original post so its the way I meant it.
My good reason for going the other way is in the body of my post. I'm well aware of why people swap OBDII to OBDI. So do you know if there are any wiring changes to swap computers?
My good reason for going the other way is in the body of my post. I'm well aware of why people swap OBDII to OBDI. So do you know if there are any wiring changes to swap computers?
Last edited by gsdave; 07-25-2008 at 08:36 PM. Reason: clarification
07-25-2008, 08:45 PM
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No wiring. I've done it. The only major difference is the knock sensor. OBD1 is 3.9 k ohm, OBDII is something like 100k, so the sensors are quite different.
You can turn off the codes for rear O2's and crank position sensor using programming software. The car will run just fine.
The reason I did it was because of my high stall Torque Converter. The OBDII PCMs handles slippery TC's better than the OBD1 computers do.
I have since dropped down on the stall on my TC and am back to the OBD1 computer. OBD1 is certainly my preference, but it's entirely possible to go OBD1 to OBDII.
You can turn off the codes for rear O2's and crank position sensor using programming software. The car will run just fine.
The reason I did it was because of my high stall Torque Converter. The OBDII PCMs handles slippery TC's better than the OBD1 computers do.
I have since dropped down on the stall on my TC and am back to the OBD1 computer. OBD1 is certainly my preference, but it's entirely possible to go OBD1 to OBDII.
07-25-2008, 08:56 PM
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Oh yeah, forgot to mentioned.
I lied a bit. I did run a wire for the OBDII communications (Blue 7 is the OBDII data line) so that I could program over the wire without removing the PCM from the car. I don't have a set of 'vette wiring schematics, so I don't know if OBDII pin 2 on the 95 ties in to Blue 7 on the PCM. If it does, then a normal OBDII scan tool or program tool will work. If it doesn't, then you may have to either use your other car, or a bench harness, to program the PCM (using something like LT1Edit for OBDII, which is what I used).
I lied a bit. I did run a wire for the OBDII communications (Blue 7 is the OBDII data line) so that I could program over the wire without removing the PCM from the car. I don't have a set of 'vette wiring schematics, so I don't know if OBDII pin 2 on the 95 ties in to Blue 7 on the PCM. If it does, then a normal OBDII scan tool or program tool will work. If it doesn't, then you may have to either use your other car, or a bench harness, to program the PCM (using something like LT1Edit for OBDII, which is what I used).
