So the other day in my 2011 G37x, I pull up to a stop sign after coming down a slow incline. At this point the road was completely level and after coming to a complete stop, I notice my car is trying to push itself forward! I look over at the tachometer and see it hovering between 1000 and 2000 RPM which is higher than it would be during a normal stop (normally it'll idle around 500 rpm). I look down at my feet to make sure I'm not accidentally hitting the gas, but my foot is no where near the gas pedal and is pushing firmly on the brakes only. When traffic cleared, I then slowly let my foot off the brake and found the car starting to move forward, so I stuck it into park then killed the engine. After restarting the car, all was well....

Has anybody ever had this happen to them? This could have caused a serious accident... I'll have the dealer check it out but I'm sure they'll come back with the usual "we can't replicate it" line that they used for issues in the past... (i.e. like with the shifting delay problem that they finally issued a patch for!)

 

Floor mat pushing against the accelerator?

 

Throttle cable temporarily stuck?

 

Just checked again and the floor mat is locked in place and away from the accelerator. Floor was recently vacummed and is free of beris...whats weird is it stayed like this until I rebooted the car...

 

Think there have been a few people with that issue. IIRC the dealer took care of it, id just give them a call

 

Are you sure it was accelerating forward and not having the engine braking? When you press on the brake, sometimes the engine surges higher when the transmission changes to a lower gear to slow down the car, which would SEEM like you are accelerating, but you really aren't. This is supposed to help slow down the car even more, especially when it is snowing/raining.

I have a feeling what you're experiencing is engine braking, not accelerating. This happens on most G's I've driven, old and new.

If your car was accelerating while you are hitting the brake, you would most likely smell burning brake fluid, which is a distinct smell.

Here is some more info on another thread about engine braking:
http://forums.nicoclub.com/2010-g37-...s-t492270.html

 

Your shoes are too big, you're pressing the brake, but at the same time pressing the accelerator.

Happened to me, true story.

 

The OP wrote "after coming to a complete stop, I notice my car is trying to push itself forward!"

The car was not moving.

 

The OP should be smelling burnt brake fluid if that was the case since it would cause the brakes to be overworked, and you would be having brake pads imprinted on your rotors, which would cause cementite to form and then have "warped" rotors symptoms.

 

Automatic transmissions will make the car move if you let off the brake and don't press the gas..

 

This was a one time thing. The brakes can hold the car still, revving between 1k-2k rpm without any ill effects or damage to them.

The OP should just go to the dealer and check it out.

 

It shouldn't have been idling between 1k-2k rpm if the engine was warmed up.

 

... damn internet explorer crashed on me after writing a post...
here's a shorter version.

#1 - the throttle on our cars is electronically controlled via accelerator pedal position sensor, a throttle control motor, and a throttle position sensor. No cables.

#2 - brakes having nothing to do with this. If the car is not moving, there is no heat build up and no warping and no brake fluid smell.

#3 - OP, both the APP sensor and Throttle position sensor throw DTC (check engine soon ) codes when they fail so it is likely yours are on the fritz or simply out of calibration.

#4 - Could be that your whole pedal assembly is just out of spec. There is an acceptable range of voltage vs pedal position. If it gets out of spec, a code is generated. Yours may be right on the edge. The factory repair manual has detailed instructions on how to test it.

If the below does not work do not mess around - go to your dealer and get it fixed.
Try this (from the factory service manual)

ACCELERATOR PEDAL RELEASED POSITION LEARNING
Accelerator Pedal Released Position Learning is a function of ECM to learn the fully released position of the accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time the harness connector of the accelerator pedal position sensor or ECM is disconnected

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.


THROTTLE VALVE CLOSED POSITION LEARNING
Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector of electric throttle control actuator or ECM is disconnected

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.

 

Uhh, as for your point number 2, you're wrong. Simple high school physics!

If the engine is applying acceleration to a car (which is true in OP's case,) a greater frictional force is needed by the brakes to stop the car or keep the car stopped. Therefore, you ARE applying more force to the brake pads. Friction causes heat, and since the brakes are required to create more friction, they can overheat. More heat- brake fluid starts to boil, etc.

The wheels won't turn until the engine's force on the wheel is GREATER than the maximum static frictional force between the brake pad and the rotor, which is why the wheel doesn't turn yet. I would bet if you rev the engine much harder, the wheels will eventually turn because the force is greater than the frictional force that the brake pad and rotor can handle. Don't give out false information.

 

Yes greater frictional force is necessary to keep the car from moving but there are two types of friction - static and kinetic (or dynamic).

Let's talk about high school physics.

Static Friction: You're in sneakers stading on a hill. Friction is keeping you from sliding down the hill. Do your sneakers or feet get hot? No.

Kinetic Friction: Your friend is dragging you behind their G37 and you're sliding on your sneakers. Do they get hot? Yes. Kinetic energy is transferred into heat.

If a brakes are holding a car still and the rotor is not rotating relative to the pads, there is nokinetic friction and therefore no heat. There is lots of static friction preventing the rotor from rotating against the pad.

Static friction does not generate heat. Static friction changes to dynamic friction when the COF (coefficient of friction is not high enough to keep two surfaces from moving relative to one another).


If you don't believe me try it for yourself. Start your car (when cold), sit on the brake, and rev the engine to 2000 RPM for as long as your wish and then feel the rotors. As long as the car doesn't move, the rotors and pads will be cold.