I bought the car for cheap, I had to change the starter and now I have to change the alternator as according to the mechanics its overcharging. Sometimes the car doesnt want to start at all. Ive checked and those times theres no current going to the starter.It usually starts up soon as I put the car in neutral though so idk. Also the car will not move out of park unless i press the shift lock in even if i press the brakes. When i drive the car it seems to be stuck in 3rd gear no matter what i do it wont shift out of third or shift down to 1 or 2. Which for me is the main problems atm. What could be the reason for all these problems? Please help me out here as its my first car and idk what to do. Any help would be greatly appreciated.

 

If voltage is wrong then it's stuck in safe mode.

 

voltage from the alternator? or somewhere else im a bit confused sorry

 

last i checked the voltage from the alternator was at 11.9v

 

yeah you definitely need a new alternator. And possibly even a battery, check that out as well. Mine's at 12.4, just recently replaced my alternator. Before I was getting numbers like yours. But honestly I don't think it's because of the starter and alternator, it's a good idea to do both there's no question about it, but when I had problems with my alt and starter the car was driveable, just really sluggish and the instrument panel was dim along with the headlights and started like ****.

Yours sounds a lot more complicated than a starter/alt/battery problem.

 

the car is driveable tbh but its stuck in third gear i can take it up to 100 km/h in that one gear but the rev goes up to 4k rpm and doesnt shift, could it be the tcm or ecm? anyone have any ideas. Ive read about the iacv shorting out the ecu could that be it?

 

Any codes?

And if you just bought the car, you should take a few hours to take it apart and learn about it and clean up as much as you can. Check wires for fraying, clean up the grounds, try cleaning your maf sensor when you take it apart. If you're up for it, try cleaning the throttle body and adjust the tps. Check the fuse box, maybe something went. It doesn't have to be the tcm and the ecm, that's too easy for this car.

 

Havent checked for codes but theres no check engine light. I dont know if the maf sensor will have anything to do with the transmission being stuck in 3rd. Ive read the owners manual which says that the transmission if it goes into limp mode will be stuck in 3rd gear. Btw the nissan maxima I have here in the gulf is the same as the Infiniti I30.
There is a button underneath the steering wheel near the obd2 port that says A/T check clicking it does nothing though. And the A/T light does not come on at all, neither does the battery light nor the ABS. I just dont know what to make of all this.

 

I've put the thing into limp mode by accident a bunch of times. Messing with the tb, readjusting the tps, leave a connector unplugged or not fully seated, not reattaching a hose properly.. It's not some achievement. That's why you should look over your car, that alone can probably fix it. At the very least it'll give you an idea of how well it's been maintained and what to expect later, Nissan wants $120 an hour for that.

 

Well Idk how to get it out of limp mode, I mean i didnt put it there in the first place I bought the car as it is. It was sitting there for a while before I bought it, mechanic thought just needed a starter replaced so I just bought it, but now theres a whole list of repairs that I feel are waiting for me. Even though I have no clue as to whats wrong with the car in the first place and Im not sure what to do. Especially about the transmission being in limp mode and what i can do to get it out of limp mode.

 

TCM will lock it in safe mode if V is too low. I've seen it do it just from a bad battery even with the car running fine.

 

hopefully youre right Im going to get the alternator replaced by hopefully today or tomorrow. Ill let you guys know if it changes anything. But till then Id appreciate any more theories you guys might have or if youve experienced anything similar to this please do let me know and let me know how to fix it. Thanks

 

It sounds like the alternator having a low voltage is causing the TCM to go into limp mode. Remember these computers have internal miniscule voltage spikes/low voltage events it has to monitor . The microprocessors when detect voltage lower than a specified amount for a specified time ( usually in milliseconds ) the shifting will go nuts.

Start by replacing the alternator, and either replacing the battery or make sure it is good, and go from there. That might be your only problem but you need a starting point .

Keep us updated

 

Just changed the alternator, no change in the shift. Still stuck in 3rd gear. Although i checked the codes rn I have a knock sensor code. The obd2 wont connect to the transmission though dont know what to do about that, it wont even connect to the abs. Just connects to the engine module and shows me just a knock sensor code. Dk what to do. please help, I feel like ive just thrown myself into a money pit....

 

I was looking up information for the vehicle speed sensor and I found something relevant to you.

https://maxima.org/forums/5th-genera...lfunction.html

Maybe you need a new speed sensor?

 

If I cant get codes from the transmission how do I know whats wrong or what sensor is gone? From what ive read it could be a whole myriad of things. Could be a short in the PNP circuit, could be shift lock solenoids, could be the TPS or TFT sensor.
I just dont know what to with this car atm.

 

those codes are ****in useless, obdii was in its infancy back then, it'll pretty much either give you a code if your car's major sensor or component went or for emission related stuff because the hippies wouldn't stfu. You pretty much solve problems on these old cars by isolating a problem and working around it until you finally get it. Sometimes it won't throw a code but it'll mess with the performance of the car, which is why you have to be proactive if you got a car in bad condition and pretty much fix things before they die on you because waiting for them to die will create 3-4 more problems.

 

Well, keep a cool head and proceed in organized manner:

• Our cars are controlled by a computer, so voltages are critically important. Fix the battery/alternator problem first. The battery voltage (with engine running charging) should be about 14.2V, 13.8V at minimum (it's 14.2V - 14.5V on my car). It should be about 12.5V when the engine is not running/charging.
• Once you have the power problem fixed, check for any codes and pending codes. You'll need a code reader, so get one - it will pay for itself quickly (like here:
  Amazon
  Amazon
  ). Thats' good tool for $35, but even cheaper ones are ok. You'll be needing it repeatedly.
• Download yourself a copy of the FSM (Factory Service Manual) from here: http://boredmder.com/FSMs/Nissan/Maxima/
• Subsequently, proceed depending on what codes you get.
• I would also check out your PNP switch - easy to do, and get it out of the way.
• Disconnect your electronic engine mounts and IACU (for background, read my document about preventing ECU failures - link in my signature, below). Re. engine mounts: I have heard, but haven't personally verified, that a bad engine mount can cause the car not to shift and not to drive fast.
• I suspect there might be something wrong with your transmission speed sensor, but it's too early to speculate.

Good luck, and let us know how it goes. Also, what's the MY of your car (3.0L vs. 3.5L).

 

finger trouble - REDUNDANT & DELETED

 

There's no special OBDII reader specific to the transmission. If there is a sensor error in your car, it will be stored in the ECU. Think of it like the internet, all your car's many computers are constantly talking to each other over a network, called the CAN bus.

I use the paid version of Torque and one of these:
You need to be able to read codes if you want to work on a computer controlled car, period.

 

has anyone tried to straight up connect a laptop to a 5th gen maxima and playing with the settings? I've never even seen a consult II before but if it only plugs into the obdii port then I'm sure any laptop with a hex editor could probably be used to manipulate values, I think I stumbled upon a recent version of a maxima ecu update and I think it was only a .Rom file, so the consult II would only have to be an emulator of some kind.

I dunno I'm taking out of my *** here for the most part, but like I said I've never seen a consult II and I don't know how it works. I don't even know how the ecu works or what it does.

 

Could the knock sensor be causing the limp mode in the transmission? Should I just fix that and hope for the best or just try something else?

Also, its the 3.0L, its the infiniti i30 in the states but here they call it the maxima.

 

No - the knock sensor and transmission are not related.
This is from Wikipedia " ... This generation of the Maxima saw Nissan introduce a Bridgestone-made engine mount with sensors that communicate with the ECM. Many transmission-like problems such as 'unable to shift into higher gears' resulted from worn engine mounts triggering signals to prevent the vehicle from gaining higher speeds ... ". (see more at https://en.wikipedia.org/wiki/Nissan_Maxima).
So, disconnect or just cut off your electronic engine mounts.

 

The transmission will cause codes in the P07xx category.

Really good code readers will give you ABS codes. Really good code readers are expensive. The cheap readers will not.

I suspect that the shift lever problem, will only start in neutral, third gear may be either a grossly misadjusted or bad park neutral switch. The park neutral switch is on the transmission, the front left corner.

 

Took off the handrest and everything it's pretty dirty



I saw these weren't connected anyone know what these are?

 

Car wont shift into gears 2 and 1 even if I put the shift lever in those gears. Should I replace the TCM and see if that helps? The code reader at the mechanics wasnt able to connect to the transmission at all. So could that be the issue? Im thinking if it was a VSS or any other sensor atleast it wouldve thrown a code or sth. Let me know what you all think. Or if youve any better ideas about what to do.

 

You keep asking question, yet you don't gfollow up on recommendation given (Have you disconnected your engine mounts ?)
I am signing off & out - good luck, you are on your own.

 

The car doesnt have electronic engine mounts, Ive checked. Ive checked the PNP switch too, it doesnt start on anything other than N or P, but Ill still get it replaced. The only thing I havent checked out yet is the VSS. Which is because I dont have a jack.

 

should be a jack in the trunk on the passenger side rear wheel behind the plastic panel, no?

 

It's a used car, I don't know what you guys expect. The jack's not there god knows what the previous owner did with it. I'll have to buy a new one.

 

If the mechanics scanner doesn't connect to the trans. module, find out why. It might be because either the TCM is not getting power via an open power wire or the fuse is popped. Or the ground side is open , if all power & ground checks out to the TCM , maybe the TCM is no good. I can't see why it would be though but you never know.

Find the fuse that powers the ECM and TCM if they are separate, also get a multi meter to check for power & ground at the DLC , the TCM connector & the ECM connector. If the scanner can't communicate with the TCM thats no good

 

Time to send the old girl to the great dealership in the sky.

Send her my regards.

 

I was taking stuff apart to take a look at the PNP and the knock sensor. Here's what I've found so far.

This I found under the airbox don't know whether it's a ground or positive. The wire seems to be red. There's a big fuse there. Please let me know what it is

This was disconnected dk how I never noticed can't seem to find a plug that connects to it. I took it off to show you guys what it looks like.

I tried searching up the part no. to no avail.

That's the connector to the knock sensor.

God knows how or what happened to it but holy ****, I have no idea what it could mean.

 

Ive checked each and every fuse both under the hood and under the drivers side. All are fine. However when I first got the car the fuses were much higher in amp than they're supposed to be. I changed them all out for the correct ones.

I don't have a voltmeter but I'll try and see if any of my friends have one. Then I'll check the TCM out.

 

All I see is a big mess. That red wire with the inline fuse means some morons were in there hacking up the electrical for an aftermarket stereo. All bets are off now. Hope you get it sorted.

 

It does have sub woofers and amplifiers, but looks like the mp3 player got ruined. I havent bought a new one yet. I want to get the transmission sorted out before anything else.

 

i'm sorry but pictures can't really gives an idea of what is supposed to be working or not, we need voltage data and verifying checking power and grounds. You can also check continuity between 2 points. Get a DVOM , even a mid priced one will work .

You can get them from Lowes or Home Depot for cheap ( a decent one will be around $20-$40 ) , and you won't just use it once, you will use it multiple times .


Also DL the FSM from NICOCLUB so you can check power & ground at the DLC, the PCM and the wiring harness.

Verifying if your problem is in the wiring harness, the component itself or the ground side will tell you what needs to be replaced .

 

Hey guys so I opened up the tcm the 880 chip had one broken connection. So I just went to the junkyard and found myself another TCM same model and everything. Now my gear is shifting so I guess my hunch was right. Thanks for all your help though.

 

Wonder if alternator blew it up.