I just recently replaced my accelerator position sensor and changed my starter. I know you’re supposed to do the ECU reset and I’ve done that, but whenever I do it, the SES light won’t blink/go away. At this point I’m lost on what to do and help would be very appreciated.

 

Post all the diagnostic trouble codes it's throwing. There's literally like 40 things that can cause limp mode.

 

The code is P2135. I went ahead and changed the pedal position sensor and had zero throttle response. I put the old one back on and cleaned the throttle body and got about 4% throttle (I checked with a OBD reader).

 

P2135 is the throttle position sensor, not related to the pedal position sensor.

 

thanks for the reply man. I’m still learning so I’m not too familiar with the difference between the pedal position sensor and throttle position sensor. I kinda thought they were the same thing just a different name. Where would I find the throttle position sensor and also do you have a good brand you’d recommend?

 

Throttle position is the throttle body on the intake manifold. Accelerator would be the pedal you push with your foot.

Three posible causes:
Harness or connector (at the throttle body or the accelerator pedal)
Throttle actuator itself
Accelerator pedal position sensor

Since you've recently changed parts, do the basic position relearns: key on (no start) for 5 seconds - key off for 10 seconds - key on for 5 seconds - key off for 10 seconds (you should hear the throttle body open and close), then try to start it.

If the throttle body is indeed bad, use the Hitachi brand part from Rock Auto (or local auto store if they sell it). Hitachi is the actual OE part, other brands may or may not work, your call if you want to take the risk.

After replacing that, you'll need to do the relearn, then do the idle relearn procedure after the car is warmed up.

 

You said previously you cleaned the throttle body, the throttle position sensor is part of the throttle body. If you are working the butterfly plate manually by hand it's VERY easy to damage the delicate internal gearing and screw up things like the throttle position sensor.

NEVER work the butterfly plate by hand. To clean around where the plate is you need to remove the two screws on the pivot bar and take the plate out. Then you can thoroughly clean everything without damaging the gear. When you put the plate back on just apply a little blue Loctite 242/243 to the threads on those two screws.

 

I replaced my throttle body and accelerator pedal position and it still goes in limp mode when I try to move it. If I clear the codes and start it back up it runs fine but if I apply any throttle, it goes right back to limp mode. I’ve tried doing the reset process multiple times and no dice. When I go to keep my foot on the gas after pressing it 5 times quickly the slip and VDC lights come on after about 3 seconds and the SES light never starts blinking. I’m aware it’s super time sensitive but I’ve done this a couple times before and it hasn’t taken near as many tries. I’m honestly stuck at this point unfortunately. I checked the wiring harness to the pedal sensor and it looks fine as well. Any advice would be appreciated. PS. Still throwing codes P2127 & P2138. Also the idle relearn and closed throttle position relearn process worked fine just not the open position

 

Those two codes means the ECM is not getting the proper data from the pedal, if you have already tried a new pedal switch then the next likely culprit is damaged wiring between the pedal and the ECM. Here is a snippet from the FSM.

You can test the pedal switch with a 3x AA battery holder to supply your 5vdc (close enough with the 4.5vdc from three AA batteries in series) and run the pedal through it's range while using a DMM to check voltage output on both switches (they are inverse of one another, one is like 0.4vdc - 5vdc the other is 5vdc - 0.4vdc when you go from idle position to wide open throttle.).

 

You can also backprobe the ECM pins 98 and 106 to see what voltage is being sent back to the ECM. All harnesses connected, ignition ON (engine off) and backprobe with a meter while you press the pedal wide open, fully released.

 

I use the NDSII app for idle relearn, so I've not long forgotten the pedal dance. But idle relearn has to be done after car is fully warmed up. Sounds like you need to check for wiring issues at this point.

 

thanks for the reply man I’m not very good when it comes to electrical work. Do you have anything I might be able to reference? If not it’s no biggie. Also would all that make sense with the car being able to rev higher while in neutral? Does it use less power due to it not being in drive? Once again thanks for the reply.

 

That is why you would have been better off in paying the one hour diagnostic fee at your local Infiniti dealer?
You still may eventually have to do that?
The dealer's expensive Consult tool will locate the problem?
Just sayin!

My $.02

 

So it will throw the exact same code with both the old gas pedal AND the new one yes?

Where did you get the new pedal from? It's possible you bought a defective one, I would return it and get another one.

If it has this issue with a THIRD pedal there's a really good chance it's actually bad wiring.

There's also a really good chance that if you got that pedal at like Autozone/Oreillys, etc that someone had a bad pedal, bought the one you have, swapped out JUST THE SENSOR, returned the pedal with the bad sensor, you bought the sensor with the bad pedal.

Also, the sensor itself can be replaced without purchasing the entire pedal assembly, most parts houses will sell it as an assembly though.