As I understand peoples tolerances with the same questions being asked over and over again in different ways. Not everybody has the same comprehension levels or same problems as they need to be addressed differently. That being said, there is so much conflicting information. Some wires are the same, some are different, blah blah blah.

None of the service manuals on nicoforum will load for me, g35driver, my350z.com and other forums won’t let me write a new post for some reason, and I’m now aggravated. You seem to know your stuff so I would need to know, without any backlash as to “use the search bar, or you can google it” because those options and all others have exhausted themselves to add to my aggravation. I cannot find a straight answer, nor solidified or concrete information on what exactly to do with the wiring. People say to wire straight to the ecu, but that is for sending certain voltage signals and distributing the power it’s given through specific wires, so some of that just seems like a good way to cook an ecu from bad info.

My ipdm doesn’t look the same as any of the pictures shown, and the only green wire with orange stripe I see is thick and coming right out of the ecu. One guy asked about and got no reply. If people knew exactly how to display important information and could post pics that will load and not be all black with no images, I wouldn’t need to kick the same dead horse everybody gets banned or muted for. I’m simply trying to figure out if I can just use the wiring that the auto ecu has to the shifter for park and reverse, under the radio and in front of the six speed shifter.

I have a Facebook and Instagram (king250sx) if somebody can message me on one of those to clarify some detailed questions I have. I can do testing and diagnostics to figure these out for sure, but I don’t see the point in tapping into the ecu when the wires for both sensors are already there from the automatic. If I break out my vom and figure out what wire is what, that would just take more time than necessary, if somebody has a straight answer I will gladly take clear pics of my wiring and show exactly what was done to get the 6mt wiring swap done, so people won’t need to ask more questions. If you’re getting a million questions, and I’m using you in general, then it’s a possibility that your information isn’t as cut and dry and crystal clear as you thought. Sorry for the book.

 

What exactly is the wiring issue you're having, something to do with the PNP switch?

That one is fairly straightforward, the 5AT the PNP switch is inside the tranny and the data is communicated back to the instrument cluster, then to the ECM pin 102 on the Green/Orange stripe wire.

The 6MT the PNP switch is mounted external on the side of the transmission and the wiring goes straight to the ECM pin 102 Green/Orange stripe. All it does is detect ground when the switch is in the neutral position.

Look up DTC P0850 in section EC - Engine Controls and you'll see a good electrical schematic of the PNP switch on the 6MT.

None of that wiring goes through the IPDM.

Just remember at the end of the day the computers don't care what the color of the wire insulation is, it just needs the electricity, data, signal, to go from the correct place to the correct place. If you have unused wires going to a place that you need then just repin or solder/shrink/splice splice to make it work.



As for the delay in being able to post, new users on all those sites (including here) are typically unable to post viewable threads or comments until a short time period has elapsed as part of the bot/scam prevention for the specific sites.

 

What pin or pins do I wire the reverse switch to? Like I said, the information is conflicted. The straightest answer is hard to find in other words. I’m gonna go wire that pnp quick and extend the e-brake wire.

 

just figured out in an idiot. I was looking under the steering column. It is NOT that module with the thick green wire with the red stripe. That’s what is confusing people. The ecu is under the glove box on the passenger side. The plug is easy to undo and pull down. It has a clip inside the pull lever to disconnect the connector from the ecu. Squeeze that and the lever together and pull down. It’ll come off. Then you can easily see the connector and ecu pins. Wasted a lot of time with this. I’m going to do the testing today and add the video to my YouTube channel. King 250sx if you’d like to watch the video. I’ll include the wires under the radio that go to the shifter. There are two common grounds on both sides once you separate the wires. I’ll show you which wires are for the reverse signal and pnp signal, and which you can use for grounds and drop them beside the transmission for a much cleaner and simpler look. Sorry for replying to this instead of writing a new post.

 

Ok reverse switch is also pretty straightforward, both the 5AT and the 6MT both used IPDM pin 26 yellow/red stripe wire.

The 5AT it then went to a relay in the fusible link that was closed by the TCM signaling the relay.

6MT it just sends power from that pin 26 to the reverse switch on the side of the transmission opposite from the PNP switch, then power goes directly to the rear taillights.

So basically what you need to do is take the IPDM pin 26 yellow/red stripe wire. Cut it and run the power from the IPDM to the reverse switch mounted on the side of the tranny, then the other wire on the reverse switch run back to the fusible link to the other side of the back up relay which is a purple wire. That purple wire will go out to the tail lights.

That just bypasses all the stuff that used to control the reverse lights from the 5AT, deletes it all and just sends power from the IPDM, through the trans reverse switch, then back onto the wires going to the rear brake lights.

 

Bro, thank you so much. That makes a ton of sense. Thanks again for taking the time to break it down. I bought my g with a bad transmission and they’re known for the solenoids in the valve body going bad. The old trans from my M was just old, but had a good valve body, so I’m going to swap that valve body into that auto trans and put it in my M as the transmission I replaced the bad trans with originally, (junkyard trans with 200k) doesn’t have park. Since my M in awd and the G is rwd I can just swap the awd unit over and it’ll be a good replacement for it. Because I bought my G with a bad trans, I decided to put a manual 6mt into it and wasn’t too sure about doing it until I found your thread or write up. Pretty much sealed the deal on it. Mostly because electrically going from auto to manual tends to be an epic pain, mainly due to security and ignition conflicts. Just saying your write up makes life easier and I’m grateful I found this.

 

So I just need an ignition signal to the switch essentially? Couldn’t I just tap into the start wire under the dash, include an in line fuse to the reverse light switch, and run the wire back to the reverse lights input wire? Probably a dumb suggestion, but it seems really simple if that’s what you’re saying.

 

Is this what you are referring to? There are two yellow with red stripe wires in the relay and I found a purple wire. If so, I have that portion of this figured out.

 

That is the fusible link with the relay yes,

The two Yellow/red stripe wires is the incoming power, use one and cap off the other. They splice a little further back towards the IPDM that is your IPDM pin 26 wire. Run it to one side of the reverse switch on the tranny.

Purple wire, it goes out to the reverse lights. Wire it to the other side of the reverse switch on the tranny.

Ignore the red wire, that one went to the TCM for the 5AT setup.

 

Also, just so you know how these things work for The Future™ the relay operates by applying voltage to the coil "spiral symbol" circled in green, it's an electromagnet, it pulls the steel plunger I drew in red towards it (there's a spring that keeps it pushed away when not energized). That is the CONTROL side of the circuit. In the case of the 5AT the magnet is energized when the TCM computer closes the circuit on pin 2.

The plunger is physically connected to the "line with two dots" that I circled in blue, that part is called the CONTACT. When the electromagnet energizes it makes the plate snap down across the two circles, contact points. Then electricity flows through from pin 3 to pin 5.

This is called an "electrically held contact", when you apply voltage to the coil it closes the contact. When you turn off voltage to the coil it's return spring pushes it back into the open position.

The reason it uses a contact for the 5AT instead of just a physical switch like the 6MT is because the TCM computer controls it and putting a relay on the TCM makes it inaccessible for quick repairs, relays wear out over time and need to be replaced. So the TCM just sends power to the external relay to close the circuit.

 

Also figured out I was referencing the pin 102 to the harness and not the ecu. Looked at the ecu and then to the harness and found the wire as it was mirrored. So one side goes to that wire then to ground? Easy enough

 

Yep, that wire goes to the PNP switch, the other side of the PNP switch goes to ground but pull it back to a GOOD ground source like where the battery negative attaches to the chassis next to it. Don't just run it to chassis metal under the car.

Use electrical anti-oxidation grease on the mating surface of the ground to ensure they don't corrode over time.

 

Sorry for the lack of understanding. Most of it came from reading other posts and the misinformation from other sources, and that created the conflict and confusion. I really appreciate your time and definitely your patience with this, but you made everything crystal clear and I was able to get done what needed to be done. Can’t thank you enough. Is it okay if I mention you in my YouTube video? Just to give you credit for the information I’m going to be providing. I just want people to have a visual understanding of it and basically a way to pause and see what needs to be done step by step, because not everybody can learn and do things just from text.

 

not sure if you found it yet or not, but the ipdm is behind the battery on the passenger side. There are some connectors near the bottom of it after you remove the cover. The one on the bottom right side. It has the most wires in it. Out of the 3 connectors on the right bottom of the ipdm. There is a grey wire with red stripe and it’s located at the top left of the connector.

 

Yeah that's fine mentioning my name, I don't mind.

Glad you got everything sorted out, it's really not that difficult once you understand exactly how the electrical schematic reads out. I'm a union electrician so I do that stuff all the time