M45 in limp mode

[Gardoslp]

06 m45 stock in limp mode it sent 3months at the dealer they replace the accelerator pedal and throttle body sensor still nothing they claim its the ecu is bad i swap the ecu with a new one the samething happen you hit the gas pedal won't rev pass 20rpm can anyone help me please inlove with my m45 dont wanna let her go

[mikew83]

Many things can send an Infiniti into Limp mode. A bad Mass Airflow Sensor, O2, cats, I wanna say the fuel injectors too... Anything that the car monitors or has sensors on (mainly connected to the motor/power train) can basically trigger it. Is it throwing any CEL codes? Are the Slip, ABS, and VDC-off lights on? Are you now getting crap fuel economy from the car burning rich to prevent itself from being deprived?

Did you do any mods to the car? I was reading on another forum that a guy brought his G35 to Canada, where they mandate daytime running lights. Infiniti claimed the aftermarket DRL's damaged the electrical system, and that caused the car to limp. Something so simple and stupid can occasionally cause this...

So without any codes or further follow-up, it's probably hard for us to get a real idea as to what's happening.

[Sstupid]

This is too general for us to narrow it down for you. We need some codes at least.

[Gardoslp]

Ok i try running the codes today battery dead ....that's another thing new battery from the dealer 6months old it keeps dying ill get the codes in da am

[mikew83]

MAYBE, and that's a big maybe, but perhaps it's your alternator going. The car is 8-9yrs old, and it could be the culprit. The same thing happened with my Lexus. As soon as the dealer installed a new OEM battery, magically my alternator went out, and that battery wouldn't hold a charge even after I replaced the alt. I made them give me a new battery despite them telling me everything checked out. As soon as I put the new one in, no more problems. Take the battery out, and bring it back to Infiniti. OEM batteries should last for 2-3 years MINIMUM! Don't let them give you any crap about they need to find a fault in order to exchange it. If they try to pull that, tell them that's fine but they're paying to tow your car in and look at it for free.

[Gardoslp]

Took 1 day and half to charge the battery but i got the codes p0643 and p4051

[Gardoslp]

The ras vdc slip lights been on for a while

[mikew83]

I presume you meant code 0451, not 4051.

Both 0643 and 0451 are part of the emission system. But both pertain to voltage not being within designed limits.
http://engine-codes.com/p0451_infiniti.html
http://engine-codes.com/p0643_infiniti.html

That could be from the car being dead for so long, and not having enough electricity to read all the sensors properly. It could also mean that your EVAP system is in need of replacing, less likely is the ECU is bad, and your alternator might also be going and not sending enough juice to all the cars systems and battery. I would take it to autozone and have them run a check on your alternator. Make sure that it's working properly. If it is, then you're going to have to start looking at your EVAP and emissions system as a whole.

Were the SLIP, VDC, and ABS off lights on when the car wasn't in limp mode, prior?

[Gardoslp]

Yes they where on con it be the tcu that make it stay in limp mode....would the emission system. Make the car smell like gas

[mikew83]

Oh absolutely it could... BUT, part of Limp Mode on Nissans, is that the car burns more fuel to try and prevent itself from stalling and so it doesn't run too lean and damage the system. So if you're smelling more gas, it could just be the fact it's limping, or it could be a larger sign of something wrong with your emissions system. That's a 50/50 toss up.
You might have blown an ABS sensor, or something is wrong with your brakes if the three lights are on together. The majority of the time, it's just because your brake fluid is low. Check that, top it off if it needs it, and they should go away. If it's not the fluid, it's far more expensive repairs, seeing as a mechanic or shop will have to do the work for you. Common causes of those three coming on together are:
-Low Brake Fluid
-Improper setting of the steering angle sensor
-Communication issue between the throttle position sensor and the abs control unit
-Incorrect wheel speed sensor input signal to the abs control unit (this can either be from a wheel diameter that is not consistent or altered wheel speed sensor normality)

Obviously if you're going through brake fluid, that's a symptom of a larger issue with your brakes, in general. But maybe start there, fully charge the battery overnight on a battery charger (take it off the car and do it in your garage or something,) and see if the codes pop back on in the morning and if the car is still limping. If it is, be sure to test out your alternator and if that still isn't the culprit, you're going to have to bite the bullet and take it into a shop

Keep us posted!

[mikew83]

Also saw this on another thread in here, might be worth looking at too, since yours is clearly having some electrical issue too
Re: ABS VDC and Slip Warning Lights


Postby mistib » Mon Nov 03, 2014 1:42 pm
I had this problem on and off for over a year. Finally found the service manual online. Here is what solved my problem:

Remove the air box (the part that houses the air filter). This will create some room to work. Find any and all ground wires that are screwed into the fender weld. There should be at least 3. Loosen these and retighten. Most people say this problem is a result of the CAM shaft position sensors, etc. no funtioning properly. It's actually the result of a bad ground.

Do this and see what happens before you spend any money.

[EdBwoy]

Not sure what I was searching for to find this thread. Interesting symptoms that I wish I had seen at the time.

Too bad, we may never know the outcome.