Hi,

FSM shows a ground wire on pin 112 of the ECU. My harness has no wire/connector in position 112.

Can someone confirm/deny this?

Thanks.

 

According to my info, yes on 95 96 ECUs, no on 97 to 99 ECUs.

 

Interesting.. Maybe I have a 95 ECU, and a 97+ harness? In that case, I have to add a wire to my harness!

 

Anyone know what kind of connector that is? To see if I can find one in the next day or so?

 

What are you trying to do to your car? and what year is it?

My chart shows that pin 112 is O2 Sensor Heater Rear Ground and pin 105 is O2 Sensor Heater Rear on the 95 & 96. For the 97 and up, both pins are empty.

 

This is an engine conversion, not in a Nissan.. Not knowing there was a difference between 95-96 and 97-99, I must have ended up with a 95 ECU and a 97+ harness.

I am using this as my setup; http://www.jimwolftechnology.com/wol...ORENGSWAPS.PDF

The car is un-driveable when cold, and when warm the WBO2 will sometimes stabilize, but it will randomly go very lean for a few seconds then recover. I can't get my laptop to stay connected to the ECU (to log data) when the engine is running. Within a few seconds of starting the engine, the computer locks up. Back in 2010 I was able to stabilize things (by adding some extra grounds) such that I could collect data and the engine ran (more or less) well. After rebuilding the engine recently, It is back to the way it was before.

I also see in the 95-96 drawing, pin 43 is signal for the TPS and CTS, on my harness it is tied in with the rest of the grounds. I never gave it much thought because both sensors seem to work properly (monitoring with the laptop), but now that I know there were changes between 95 and 97, I am going to try and rewire mine to match the 95 drawings.

Any suggestion on which pin to "sacrifice" for 112?

 

These pins are not listed in the Jim Wolf pdf link so they sound like volunteers. Pins 103, 107, 110, 114, 118 and 120 Only one minor flaw with these pins is that most of them are not in the 1999 harness. I hope you don't have a 99 harness.

If you would like, I will send you the chart I am referencing. The chart is a pdf file and I have to e-mail it to you. If you are interested, send me a pm with your e-mail address.

 

I ended up using a pin for a EGR sensor.. Something I will never have.

After wiring the grounds as shown in the FSM for 1996, the ECU seems to be stable now. I can connect the laptop to it. It is still running lean, but that is another issue I can deal with now that it is stable.

Thanks so much for your help!

 

Excellent! Love to hear happy endings.

 

Engine is still running very lean. Right and left O2 sensors read "0" on the laptop most of the time... The jump up with a quick bump of the throttle.

WBO2 read's lean most of the time. Goes slightly rich with a bump of the throttle.

Is there some other difference that I need to account for in using the 97 harness on the 95 ECU?

Thanks.