Q: Engine races or revs while driving.

asked by on

While driving my pick up, the engine will race and seems like it is trying to shift gears, up or down. This happens once you reach 45 to 50 miles per hour.

My car has 68730 miles.
My car has an automatic transmission.

Hi There, This may be a sign of low transmission fluid or a faulty transmission control solenoid. As you’re going down the road, the car’s 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 upshift / downshift by sending a signal to one of several shift solenoids. These transmission solenoids have a spring-loaded plunger inside, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes the plunger 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 car’s 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. Or, the Engine Control Unit can control the solenoid’s plunger by turning the ground circuit on and off. A solenoid can be used to control a single gear or multiple gears, depending upon the complexity of the design.

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
  1. Home
  2. Questions
  3. Engine races or revs while driving.

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: Transmission made grinding noise when I shifted from park into reverse or from drive into reverse

It sounds like the problem is in the transfer case. The fact that you have to put it in 4wd to move the vehicle tells me that it is in the transfer case. You either have a problem where it...

Q: I would like to swap my 4.7L to a 5.7 L

Hi there. Unfortunately, since this is not a service that our mobile mechanics offer, we're unable to offer you the right tips for ensuring that this type of motor swap would be successful. However, one thing we can tell you...

Q: P0068? Runs rough and idles high

Hey there. This may be a sign of a faulty MAP sensor. The Manifold Absolute Pressure (MAP) sensor is a key sensor because it senses engine load. The sensor generates a signal that is proportional to the amount of vacuum...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.