I am messing around with different ground points, and so far the MAF sensor ground made the most noticeable difference so far. The others that make the most sense to me are the ECU, and TCM. Does anyone have a picture of how they grounded those? Also, did you ground them inside the car, or ran wire to neg terminal? I will post my thoughts after so others can decide if they want to do that.

thanks!

 

You can ground something by attaching a probe or wire to a bolt on the valve cover. Why do you think there are random wires attached there from the big bar of tape? Those are grounding wires.

 

I get that, but some kits include extra wires to the TCM and ECU, and I have yet to find instructions on how and where to connect these>

 

What kits?

 

I believe BlehmCo, and I know I have read about at lest one other. Those two points actually make a ton of sense.

 

An earlier poster already pointed you in the right direction. The main ground points for the ecu are located in front of the valve cover... i believe its the 2, 10mm bolts between the front valve cover and the intake manifold.

Perhaps the kits want you to reach those ground points? Or you can consult an electrical diagram and ground the ecu at one of the ground points on the ecu terminals. I'm not going to get into how horrible the engine harness is on the 4th gen. I personally feel that Nissan used inferior wiring (or design). Many problems seem to be attributed to the wiring not lasting the test of time.

The ONLY reason that adding ground wires help ANY vehicle, is that the ground points from the factory have deteriorated to the point that they have a bad connection. All that b.s. about not sanding down the transmission caused this and that... I call b.s. Add new wires to the factory ground points, pray that your harness has no breaks or shorts... And you should have no problems.

On the other hand, it lasted ten years and perhaps that is the lifespan it was engineered to withstand. Comments are welcome, but if you do comment. Please add scientific evidence. i.e. use of a multimeter and measure the resistance of the transmission ground points being inferior to those on the engine itself. Just don't tell me you added grounds and now you "think" your car is better etc.

 

you sort of contradicted yourself, by saying how poor the factory harness is, and then calling bs on the idea that adding ground points to an inferior design might help?? My impression of the kits that include wire for those points actually ground TO the ECU and TCM inside the car itself... I did not post to argue the merits of the kits. I did add to the factory points, as well as clean up those points, and added a ground to the factory one on the MAF.

 

Yes I know I contradicted myself. I am saying that the design has flaws but it lasted 10+ years. I believe that it served its lifetime. Adding grounds will help IF you have poor factory wiring. I traded a 96 pathfinder stick-shift for my 97 max, and I love the max... But yes they had a service bulletin about the engine harness.

 

that is most likely the reason so many 4th gen owners report improvements from these kits. Now what I am trying to do is find the most common sense places to add these grounds. We all know the autos react for s_it, so the TCM makes sense, and if we have cars with 12+ yr old wiring and sensors, anything that would clean up signals from the ecu would make sense? So, do you think that finding a place on the actual ecu to ground would be a good idea?

 

Yeah, I can look at the factory wiring diagram and tell you which terminals are ground points on the ecu itself. And I agree that grounding there would help if the factory grounds are bad.

However I will warn you that there are tons of wires connected to the back of the ecu. This will require soldering a connection onto the wires at the corresponding terminal. These wires are really small but it is not too difficult to do. I hope that I am making sense here.

 

yes, the posts I have read, make it sound like there a spot on the actual ecu box to attach a wire and run into the engine compartment??? I for sure see what you are saying, and actually running one from the actual ground wires on the harness would be a huge help. Like I said the extra wire I ran from the ground wire on the MAF ground wire, fixed a inconsistant idle issue I have had for a month or so, that the ground kit didnt touch.

 

I do not know how to copy and paste items from the factory service manual. If you have downloaded the manual then pages ec-95 and ec-96 tell you the terminals on the ecu and the corresponding ground points, sensor inputs etc. At one point another member, pmohr posted this information on maxima.org as well.

 

thanks! I will check it out...

 

yeah i jus bought some 4awg and bout to do a ground kit myself. Let me know how it works out Tony.

 

I will, but I am still looking for directions on a kit with the 2 extra wires going to TCM and ECU I realize you should buy the kit from that person, but I had one already and then saw the other kits. So, maybe if I would buy the 2 extra wires from him he would show me how to mount them???