Q: Check engine light is on and keep jerking and cutting off and want crank

asked by on

What does it mean when your car check engine light is on and is jerking and won't crank

My car has 1489 miles.
My car has an automatic transmission.

There a couple of things that will typically cause the jerking reaction you are describing, both of which will also cause the check engine light to come on as well. The camshaft position sensor measures the rotational position of the camshaft and transmits that information to the engine control computer. To determine which cylinder is in its power stroke, your car’s computer monitors the rotating position of the camshaft relative to the crankshaft position using a camshaft position (CMP) sensor. It uses this information to adjust the spark timing and the operation of the fuel injectors. Thus, the CMP sensor affects fuel economy, emissions control, and engine efficiency. The two most common camshaft sensors you’ll see are the magnetic and Hall-effect types. Both transmit a voltage signal to an electronic control module or to the car’s computer. The magnetic type produces its own AC (alternate current) signal (a sine wave), and you can identify it by its two wires. The Hall-effect type uses an external power source to produce a digital signal (a "square wave," on-or-off) and has three wires. Depending on the specific model of your car, your engine may have one or more cam sensors. When the camshaft sensor fails, you may experience the car jerking while losing power or the car may struggle to move faster than ~35-40 mph. The engine may also stall intermittently, produce poor performance, hard starting, surging or fail to produce an ignition spark.

The other possibility may be a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. I would suggest having a professional from Your Mechanic come to your home to diagnose and inspect your vehicle.

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. Check engine light is on and keep jerking and cutting off and want crank

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: Q: Driver door won't open from inside or outside.

Hello. If the door will not open, then the issue may be the latch, but it may also be the linkage that connects the handles to the latch. You will need to access the inside of the door panel to...

Q: Q: Car wont start

Hello, thank you for writing in. The vehicle may be having a programming issue. The security system may be locking you out as a result. You need a high-tech scan tool to properly pull enough information from the vehicle to...

Q: car cutting out in low gears on stopping, traffic lights and junctions

Hello. This is often times a sign of a failing mass air flow sensor. As you may know, this is a unit that monitors the air flow into the intake as it is mixed with the fuel prior to being...

Related articles

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...
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...
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.