Q: My car jerks when it almost comes to a complete stop

asked by on March 08, 2017

I recently bought this car and I've noticed that it jumps or jerks forward when I almost come to a complete stop. It's like right before I fully stop that it does it. When I accelerate it changes gears it's kind of sluggish but it's not too bad. I have a "live" MPG cage on my car and right before the jerk it goes all the way down like I'm pushing the gas but I'm not and my RPM doesn't change. My RPM only moves a little when I'm waiting at a stop and it vibrates the car sometimes. I mainly want the jerk fixed. I don't think it's the brake rotors or pads because they look fairly new. Could it be the transmission fluid? Does it need to be changed? Does it need to be flushed? I can't check it on my car because it's under the car.

My car has 120000 miles.
My car has an automatic transmission.

Hello, What you are describing may be a result of a faulty speed sensor, potentially low transmission fluid or a even a faulty transmission control solenoid. As your vehicle travels down the road, the computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshifts and downshifts by sending a signal to one of several shift solenoids. These transmission solenoids have spring-loaded plungers inside them, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes these plungers to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road. The computer controls the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. In some cases, the Engine Control Unit (ECU) can control the solenoid’s plunger by turning the ground circuit on and off. When this is not working properly, this can cause a jerking reaction, a delay in shifting or in some cases may cause the transmission to hesitate in shifting gears. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your transmission.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

P0011

Hi there. It sounds like you have a fault in the camshaft position sensor circuit. This fault could be the sensor, the wire harness, the connector, the ECM, or even a mechanical condition. You'll need the manufacturer's specifications for the...

Traction control light is on, 2000 BMW

As you know, your car is equipped with wheel speed sensors at each of the four wheels which monitor wheel speed while relaying this information constantly to the ABS and traction control system which are controlled by the car's ECU....

Where is the circuit one camshaft position sensor located?

Hello. The camshaft position sensor is located on the passenger side of the engine bay, on the cylinder head near the coolant reservoir tank. The reservoir tank needs to be removed in order to access it. If you need help...

Related articles

Top Automotive News & Stories: October 1-7
BMW i5 images leak, an ultra-lux Jeep, hydrogen-fueled Colorado ZH2, Fisker's electric future, record plug-in sales, NHTSA Road to Zero, and more.
The Best Used Cars to Buy if You Live Close to the Ocean
If If you live close to the ocean, your vehicle is going to be far more vulnerable to rust than if you lived further inland. And the fact is, when it comes to resisting rust, not all vehicles are created...
A Buyer’s Guide to the 2012 BMW 3-Series
The The 2012 BMW 3-Series has been wildly popular in the US since it was first introduced in 1975. This series of luxury sedans sets itself apart from other luxury models with its superior performance and driving dynamics. No matter...