Hello everyone,
Forgive me if this is not the right place to post. I've been a huge fan of forums since I was able to turn my first wrench, this is my first time ever posting on one. A little back story about my circumstances in hopes to get solid answers other than the usual "buy another car" or whatever generic response you usually see when someone asks something. By the way, not being rude just going by what I've seen so please don't take it that way. I am currently raising 5 kids so of course funds for my hobby are limited. I know how to work on anything on a car aside from actually tearing a transmission apart, I'd give it a shot though if needed. I'm very handy with tools and can even improvise. Zip ties are awesome, giving this little bit of info so you can see what I'm willing to live with on a car. Don't get me wrong, I do everything right and take care of my vehicles but a little bit of "redneck ingenuity" never hurt. I love the idea of built not bought and feel that anything can be done with a car with of course money and time so nothing is ever out of the question. Cars to me are what replaced horses and if I feel a "connection" with the car, I know it's meant for me and will last me an extremely long time.
I recently bought an 05 G35 sedan with the auto transmission. This is my first foreign car other than a Honda and I have to say, I know what I've been missing out on. I love this car and is so damn fun and comfy to drive, like it hugs me and does exactly what I want it to do. Why don't more people have one of these blows my mind. I've had it for about six weeks or so and it currently has 195k miles on it. It's clean for the year but not without it's quirks.
Right now, it has the issue with the manual mode being spotty. I knew this when I bought it. Sometimes it'll work, most of the time not. It seems to really work when it's below 40 degrees in the morning on the way to work. I've read and read and read many threads on many forums and see that there are common areas of issue like the gauge cluster needing repair or replaced, the manual gate, old transmission fluid or something like that (was one of the topics I've read) among other things. Of all this reading, I have a few questions...
1) What is it in the gauge cluster that needs repaired or replaced for the manual mode to work? My cluster has the fuel gauge issue (I've already cleaned the metal pieces on the sending unit and pump, sorta fixed but not) Left blinker light works in a blue moon, emergency brake light not working, cruise control set light doesn't work, not sure about other lights. I've read where people have had theirs sent off for repair but can't seem to find anywhere exactly what got repaired other than "It was just re soldered".
2) Are there ground wires anywhere behind the dash or in the center console that can be cleaned? I've already cleaned the grounds in the engine bay, they seemed good but cleaned them anyways.
3) Can the switches in the shifter assembly be replaced by a new switch or does the whole assembly need to be replaced? I don't mind taking the shifter assembly out and taking it apart to put a new gate switch or whatever in, honestly I like that kind of work.
4) Aside from all this and not going the route of putting a manual trans in (I know, buy a manual instead of building but I wouldn't mind building, would be more fun to me) has anyone ever done any mods like a different shifter assembly from another car or performance aftermarket tiptronic assembly?
5) Transmission solenoids and valve body? Like I said, minimal experience with working on transmissions aside form usual maintenance but am confident in my abilities to do so if needed.
Any advice on this from people that had this issue and have had it rectified for permanent results, doesn't matter if jerry rigged or an actual fix, would be amazing. Having manual mode but not being able to use it just sucks. I'm almost at the point of making it to where the car never seemed to have manual mode as an option, don't ask me how but I already have an idea of what I can do lol. Much appreciated, I will only respond to constructive reply's about fixing this issue, anything else is ignored.

 

Whats up man!!

Sounds like most of your problems are due to a bad cluster. I dunno what Nissan did when they made the clusters for these cars but the PCB boards inside suck asś. It seems they have a tendency to break contact due to cracked solder joints and even inside the actual circuit lines in the board itself.

I had the erratic fuel gauge issue on my car…someone figured out that there are a few resistors on the board that need to be re-soldered and that will fix the issue. I have done this fix to multiple clusters already.

As for the manumatic issue, if you have verified that the micro-switches at the shifter assembly aren’t the problem, then that issue is also due to your cluster. (I’m betting it is).

I bought many used clusters in hopes of experimenting and figuring out “the fix” for the notorious manumatic issue but had no luck. There are about a thousand resistors and other kinda electronic chips on the board….really really tiny ones. I used a fine point soldering iron to re-solder all the ones I possibly could, but that didnt help. Most of the chips are impossible to solder by hand because of their micro size. I have even went over the whole board with a heat gun in an attempt to soften up the solder and maybe re-weld and broken contacts. Still no help!

In my experimenting with multiple cluster gauges, I found many of them had LED lights that were intermittent, and would come on if I actually bent the board slightly in a certain way, or applied pressure in some parts of the board. I’m pretty sure it was because of broken contacts throughout the inside of the board circuits. I encountered these kinda issues with cruise control lights, blinker lights, parking brake lights, rpm backlight lights, and the digital odometer backlights. Some would be inop, some would be intermittent, some would flicker between bright and dim. And I know it wasn’t a burned out LED bulb because I would replace the LED bulb with a new one and it would still act the same.

Maybe an electrical engineer would be able to figure it out…but its way above my knowledge. I just ended up buying a few different used clusters and got lucky with the last one. Everything works fine now except for the SET light when I set my cruise control speed. I am willing to live with that lol.

Here’s a few pics of the cluster board if u wanna see:

 

You can clean the micro switches for the MM on the shifter by spraying them out with a plastic-safe electrical contact cleaner. Just make sure the can actually says plastic safe.

 

I can't help the poster with his question about how to fix the MM mode but I can share a couple of other combo meter issues. My whole odometer (lcd?) section is now dim. I can barely see the odo and trip meter values but they're there still. Just not bright. This is new for me in the past couple months. I also fixed the bad fuel gauge reading a few years ago by resoldering the resistors. I don't know how that guy that posted those tips figured that circuit out. Without a schematic I don't see how you can figure out what signals are going to what components on that board. We could figure all these problems out if we had detailed schematics but without them it seems impossible. I just joined a Nissan Murano forum as I picked up a clunker for free and (unsurprisingly) they have combo meter issues too in the same timeframe.

 

It's not a matter of tracing out each circuit on a PCB it's basically just understanding what components you need to perform certain functions and then identifying which component types are most likely to fail. In the case of 2000 era Nissan instrumentation it's the resistors peeling off the PCB because they used surface mount resistors instead of the type with leads and the solder was peeling away after years of expansion/contraction due to seasonal temperature changes. The solder is the actual culprit though since basically everyone switched to surface mount ones to save space on the PCB.

Every vehicle on the road has some kind of chronic issue though, look at 1st gen Ram trucks with the chassis literally rotting to pieces, Ford DPS6 dual clutch transmission eating a clutch every 50k miles, Mitsubishi turbo 4 engines chucking crankshaft thrust bearings, every Chrysler car ever made in the past 50 years. It's incredibly uncommon to find a vehicle like the 1980-1990s Jeep Cherokee that just runs and runs and runs and nothing ever breaks.

The best case scenario is the problems your vehicle may have are easily fixable, in the case of the V35 it's cam/crank sensor, rear diff bushing, drinking oil, and the instrument cluster and that's not too bad honestly. V36 it's the galley gasket which is more of a pain in the *** then all the V35 problems combined. Overall the G35 is one of the more reliable vehicles of it's class during the era when it dominated. BMW 335i had bad high pressure fuel pumps for their DI system, Lexus/Toyota was plagued with MASSIVE interior electronics problems, even Honda shat out a few lemons like the Accord V6 from the early 2000's.

 

rip my 01 Honda accord transmission. Trans made in Toledo with a partnership with GM, clutch pack went out at 90k miles right outside of the warranty period I was never given notice about.

I’ll take 200k mile engine gallery gasket issued any day.

 

Thank you guys for your responses. I was busy over the weekend with various things around the house as well as tinkering with the car. I went thru and made sure that the contacts for manual mode are working and making contact as well as just double checking grounds and such. I do feel that it is my cluster. My manual mode worked great all the way to work this morning though so at least I get to play with it a bit before it's out lol. Seems that Nissan may have cut corners in some areas while producing these cars.
Has anyone ever tried seeing if we can separate the functions of the cluster with manual mode on the shifter assembly without messing anything up? Or is the cluster crucial for manual mode and any other functions of the car to work? Just a thought. I wouldn't mind "frankensteining" if there were options without destroying anything.
I did find a company on Google as well as a couple of Ebay stores that are able to repair this in the cluster itself or they sell already fixed clusters that address this issue. I'd love to do it myself but seems like this is a secret stashed with the ones that know how to fix it.

 

The manumatic switches go to directly to the instrument cluster computer, the cluster is what tells the TCM via the CANBUS network that you want to shift up/down in MM mode.

 

Cleric670,
I've seen your posts in many threads and I've seen you speaking of the CANBUS system. I for one, have no knowledge of this system or it's workings. You seem pretty knowledgeable about it considering I haven't seen anyone else talk of it as extensively as you. With that said. Do you know a way to cut this out? Like a stand alone system or something? I know that these systems are crucial for proper functionality of the vehicle but I wouldn't mind exploring options that wouldn't harm the car, performance or hinder any upgrades I'd like to do in the future. Or, would it just be easier and cost effective to just get a new cluster and hope the issue doesn't come back some time down the road?
Sorry for my questions, just trying to see if anyone has ever done their own garage mechanics and found their own thing that has worked. If nothing comes up, I'm down to just replace the cluster and move forward with the car. I can almost handle no manual mode as the car is still almost just as quick, fast and fun to drive without it anyways but having the ability to control it is an awesome additive.

 

I would get the cluster fixed, maybe using a free one from the forum member literally giving them away, until yours is fixed.

 

Under the marketplace you can find free clusters. I can’t remember who is giving them away for the cost of shipping.

 

And if you want quicker shifting, explore the TransGo kit. Lots of threads on it. Manumatic is not quicker. But it does let you be more involved in the driving.

 

 

Oh sweet! I really appreciate everyone's help and insights into this!

Scorpio0, I will send you a pm.

 

Definitely just get a working cluster, as for CANBUS basically it's a network between the various computers in a car so they can all talk to one another. There's like 7 different computers ECM, BCM, TCM, ABS/VDC, RAS, SRS, IPDM, plus a bunch of other stuff like heat/AC, instrument cluster, steering angle sensor, intelligent key, the seat control unit, etc. This allows them to all communicate essential stuff without requiring a bunch of extra wires. The CANBUS is just a two wire system that the computers all throw a bunch of data on and whatever other computer needs it can find it, especially helpful since some computers need the same information for different things.

Imagine a piano, it has 88 keys, but they all create SOUND which is a measured type of frequency. Your ear hears them all differently, because it's just a different frequency of sound that goes into your two ears. CANBUS allows for different digital frequencies over the same two wires and the different computers are allocated a certain spectrum of the frequency they can talk in but all the computers can hear the entire spectrum.

This is how your diagnostic trouble codes work for example, if something is wrong with the TCM it puts up it's error code on the CANBUS system, the instrument cluster is designed to listen for those specific frequencies so it hears the information and it's computer will then turn on your check engine light and the error code is also heard by the ECM which stores that code to it's DTC memory so you can plug in a handheld OBD2 scanner (which is also communicating on the CANBUS system) to retrieve the code.

To ACCESS the CANBUS system you use a protocol called "K-line", basically when you plug in a diagnostic scanner the system recognizes it and allows for diagnostic scanning which can be a LOT more in-depth than what a basic scanner can handle. Specialty tools like the dealership CONSULT-II or III software are custom designed to fully access ALL of the systems for Nissan vehicles. It can see realtime oscilloscope data for all the hall effect sensors (cam and crank sensors), reprogram computers, override ANY vehicle function, access a mountain of hidden toggles, or perform ANY function that would normally be handled by the computer.

As far as I'm aware there are no plug in modules that allows for the upshift/downshift CANBUS for Nissan cars even though it is possible. If someone were to isolate the exact frequencies they could just be injected onto the CANBUS system right from the OBD2 diagnostic port.

I have no idea how to do that though, I understand how the systems work but I haven't got a clue how to actually do something like that though.