image_01
mechanic servicing engine image

CHECK ENGINE LIGHT ON

Most cars and trucks have an on-board computer that constantly monitors sensors from the engine and transmission to warn you if something is wrong by turning on the check engine light.  The main reason the computer monitors these sensors is the ensure your vehicle is operating efficiently with the lowest emissions possible.

Why Is The Check Engine Light On

There are hundreds of possibilities to why the check engine is on. If you wait too long to find out why the engine light is on you could cause damage to your engine or transmission.  If your check engine light stays on without flashing this usually means the problem is less severe but should not be ignored. Now if your engine light is flashing this usually means there is a serious problem and you need to get it check immediately.

    Common Engine Light Warnings

  • Loose gas cap
  • Bad mass air flow sensor
  • Catalytic converter
  • MAF sensor or circuit
  • Engine running too lean or too rich
  • Cylinder misfire
  • Knock sensor circuit malfunction
  • Insufficient EGR (Exhaust Gas Recirculation) flow
  • Failing oxygen sensor
  • Bad spark plugs or ignition coil
  • Engine vacuum leak

Engine Light Diagnostic

While anyone can use an OBD (on-board diagnostics) scanner to read the vehicles trouble code as to why the check engine light is on in most cases only a certified mechanic will be able the diagnose and fix the problem.  The information you get from an ODB scanner only tells you the general area of the problem.  If the engine light comes on and the scanner tells you there is an EGR Sensor problem this does not mean you just need to replace the sensor.  There are many reasons why the sensor is detecting a problem.  Our certified mechanics have years of experience in engine light diagnostics and know how to fix any problems your vehicle may have.

Don't Ignore The Engine Light

Ignoring the engine light warning will end up costing you more money from poor fuel economy or damage to the engine or transmission.  While the engine light is on your vehicle will not pass a smog test either.  Bring your vehicle so we can save you time and money.

CHECK ENGINE LIGHT

check engine light image

POPULAR QUESTIONS

  • Can I just turn off the check engine light?

    Sometimes the check engine light could be on for something as simple as your gas cap did not get closed properly.  But there are hundreds of other reasons the check engine light could be on and some of those reasons could turn into a costly repair if not checked right away.  We recommend you have your vehicle checked asap if your check engine light comes on.

  • Will the engine light come back on if I reset it?

    If you don’t fix the problem that caused the engine light to come on the answer is yes.  The engine light will come back on if you just reset it.  Once the engine light is off it may not come back on right away because the computer usually checks to see if the problem still occurs after 3 drive cycles.

  • What is the difference between OBD1 and OBD2?

    OBD1 (on-board diagnostics) was original designed to diagnose emissions control systems.  OBD2 was introduced in the mid 90’s with greater vehicle diagnostics and provides standardized trouble codes.

© Copyright 2016 Bob Lee Automotive