Thread: How to repin later OBDII ECU to work with early OBDII ECU

What does the pink, green and blue represent? I assume blue is no change to the pin? Pink, green?

I find it hard to believe JWT got it wrong all of these years and no one else has had an issue....

Not sure on 99 P11's, but on a 99 B14 SE-L, JWT instructions worked perfectly. Move 3 pins, unplug a few sensors, do some vacuum line changes and done. No codes ran perfectly fine boosted.

Pretty much you got it right blue is no change, pink is automatic transmission related, and green marks differences or extra stuff, it was just done as a guide to help be cleary see teh differences. JWT didnt actually specify this for the 99 P11 so the only thing I really see wrong is swaping pin 111 to 112, pin 111 needs to stay were its at and you need to splice into pin 111 to be able to provide a ground for pin 112

Ah I see what your doing there, JWT instructions tell you to swap wires and to switch to an old skinny o2 sensor that has less wires. Your method is more for retaining the 4 wire stock fatty sensor on 99+.

Actually no you still need to switch to the 3 wire o2 sensor, but if you look at the wiring schematic you'll see pin 112 provides all these ECU's with a ground for the ECU, JWT is telling you to remove this ground to pin 111 which would remove this ground completly which provides additional grounding for the for the shielding wire of the resistor of pin 2 (which the shielding isn't actually present on the 99 P11 at pin 2 but is on the 97/98 B14) and pin 112 also goes directly to one side of the power transitor for all the ECU's to include the B14 97/87 ECU'S.

You meant to type 3 wire o2 sensor, right?

Yea thats what I meant, i'll edit that right now.

Hi Guys!! A little update on this August 2014. As an owner of a 1998 200SX SE-R using a 1997 ECU I asked JWT (Ben Pila) about this and here's the official response:

Hi Luis,

I double checked with our lab engineer about the pin 112 to pin 111 wiring question you mentioned. Pin 112 is a ground and if you notice on the factory pin out diagram, that it ties into the same ground wires as pins 106, 118, 38, 10, 19, 44, 40, 41, 45, 43 and 39 and maybe a few others. All these tie to each other and then go back to the engine block or intake manifold as their final termination. Our engineer says the 3 ground wires attached next to pin 112 are all the same ground plane therefore are "redundant" grounds. So borrowing one of those grounds to make the ground happen to pin 111 which is the O2 sensor heater circuit, is not a problem. So our diagram is correct and our wiring information is also correct. It is much easier and cleaner to simply de-pin the pin 112 and move it to pin 111 than to try to physically solder on a jumper between pin 112 and pin 111. Pin 111 on the 98 does not even have a pin or pin/wire in that location. So moving physically pin 112 into pin 111 is the best option for a reliable and functioning circuit. So the SR20 forum person/people that made the posts about this are incorrect and our information is correct.

Just wanted to share this info with you all.

Luis