Skip the auto shop - Our mechanics make house calls

Q: Why is my car accelerating by itself?

asked by on

I was driving my truck at a doctor's appointment and I was backing out the parking lot and it accelerating back and I almost thought that I hit a car. And it happened to my brother who was driving the truck and he said that accelerated on him too. I want to know why it is accelerating what I can do to fix it.
My car has an automatic transmission.

This vehicle engine has a manual throttle cable and cannot accelerate by itself. You may have a faulty idle air control valve that can cause a high idle but is limited to only about 1250 rpm. I would recommend having the floor mat checked to make sure it is not obstructing the gas pedal in any way. If that’s not the case, have the computer diagnosed by a certified technician, like one from YourMechanic, to see if there are any codes for the TPS or IAC. If anything comes up, the codes need to be diagnosed and repaired as necessary to fix this issue.

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: Car stalled but restarted after resetting fuel safety cut off switch.

A car can stall for many reasons, including problems with, the fuel, air, or spark/ignition systems. I would first scan for any trouble codes, that may possible shed some light on the cause of the problem. If not I would...

Q: How long and what is the process to replace a fuel pressure sensor?

A professional mechanic would require roughly 5 hours. (If just the regulator is replaced that takes about 1 hour). Some parts, as noted below, cannot be re-used, you need a precision inch pound torque wrench, FSM instructions (and TSB updates...

Q: "Service AdvanceTrac Required" message 2012 Ford Mustang GT

Hi there. If the “service AdvanceTrac” warning indicator light comes on in the dashboard, this could be an indication of several issues including, a faulty wheel-speed sensor, a faulty steering-angle sensor, faulty rotational-speed sensor, issue with the steering rack or...

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...