Skip the auto shop - Our mechanics make house calls

Q: High RPM's when pressing brake

asked by on

I just bought a 2004 Nissan Maxima and im having problems with the rpm's running high. When I hit the brake the rpm's go up a few hundred and then will come back down and when this happens I can feel the jump in acceleration. Also BC the rpm's run high, when u go to shift into another gear without letting the rpm's come down, it will shift hard making it feel like my transmission is hitting hard. Anyone know what could b causing this???

My car has 162000 miles.
My car has an automatic transmission.

Hi There, There are 3 sources of signals that are involved in up and down shifting points the computer arrives at to direct transmission shifting.

  1. The Idle Air Control Valve. The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal.

  2. The Throttle Position Sensor. The throttle position sensor monitors the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. Based upon the inputs from the sensor reading your foot’s position on the pedal, the ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal.

  3. VSS speed sensing. The transmission speed sensor is a magnetic sensor that provides this information, allowing the transmission to shift smoothly. The sensor counts the internal number of revolutions of the transmission and transmits that information to the transmission control unit, where the data is used to determine the rotational speed. As the rotation increases, the control unit directs the changing of gears. When this is not working properly, this may cause the transmission to shift erratically or in some cases not at all.

I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your vehicle to determine what may be causing this.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Clicking sound trying to start car

Hello. The most common part of this problem is the starter not working properly. What happens is the starter solenoid is not engaging the starter when the key is turned, which would cause a clicking noise. The worst case scenario...

Q: Noticed a small spot on my driveway, I think I may have a tiny oil leak. Is it still ok to drive?

Hi there. A couple of small spots is sure sign that something is leaking. What color are the spots? If they are dark they could be engine oil, if red they could be transmission fluid. A leak is something that...

Q: Runs ok but once it warms up it dies

Hi There, This may be a sign of a faulty ignition coil. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly The insulation develops small fractures that open when heated...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.