Skip the auto shop - Our mechanics make house calls

Q: Check Engine light on

asked by on

The Check Engine light is coming on.

A: The powertrain control module (PCM) takes i...

The powertrain control module (PCM) takes inputs from dozens of sensors. It then uses this information to control outputs such as fuel delivery and emissions equipment. If the PCM detects a problem anywhere in the system it will illuminate the Check Engine Light. There are literally hundreds of potential causes for the light being on. A trained professional will be able to retrieve the corresponding diagnostic trouble codes to analyze your vehicle and make the repairs that will clear the Check Engine Light.

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: Rough idle and low power

Hi, thanks for writing in. It sounds like you have timing chain related problems for sure. The central component, your timing chain, which maintains a critical relationship between the crankshaft, and the camshafts on your engine, has likely chewed up...

Q: Check engine light is on

Hello. If the trouble codes have remained after the crankshaft position sensor has been replaced then it may be possible that the issue lies elsewhere. P0335 is the trouble code for a crank position sensor malfunction. The circuit includes the...

Q: My battery went dead, replaced it with a new one and within 150 miles the Check Engine Warning Light came on.

There are a relatively large number of Technical Service Bulletins that GM has issued covering faults and difficulties with electrical components in your vehicle (ref: National Highway Traffic Safety Administration on-line database which we searched for your year, make and...

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...
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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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.