What To Do When Check Engine Light Comes On In Your Volkswagen Jetta?

A modern car engine is regulated by the engine control unit (ECU) or engine control module (ECM). It is a pre-programmed unit that regulates the engine operation on the basis of data received from different types of sensors. It controls the air intake system, fuel delivery system, and ignition system. Moreover, it also regulates the opening and closing of different valves to keep the engine operational. If it detects irregularities in the engine operation, it will warn the driver about the problem by turning on the check engine light on the dash. So, illumination of the check engine light or malfunction indicator light on the dash of your Volkswagen Jetta should not be ignored. Let's discuss some of the most common causes of check engine light illumination on the dash of a vehicle.

Common causes of check engine light

Bad oxygen sensor

The job of an oxygen sensor is to measure the quantity of unburnt oxygen in the exhaust system. The ECU uses this data to regulate the air-fuel ratio within the cylinder. However, a defective O2 sensor fails to do its job and could provide wrong information to the ECU which could adversely affect the engine operation. You might also experience engine misfire and stalling. When the ECU gets aware of the problem, it would turn on the check engine light to warn the driver. Replace the faulty O2 sensor as soon as possible to keep the engine of your Volkswagen operational.

Defective catalytic converter

The catalytic converter is a vital component of the exhaust system. Its purpose is to convert noxious exhaust gases to less toxic or inert gases. By doing so, it minimizes vehicular pollution. However, a defective or clogged catalytic converter could not do its job properly as a result of which your Volkswagen Jetta might fail an emission test. Besides, a defective catalytic converter could adversely affect the engine operation in your Volkswagen. Malfunctions in such a vital component could trigger the check engine light to come on.

Failing ignition system

The ignition system generates electrical sparks to burn the air-fuel mixture within the cylinders. The ECU regulates the timing and angle of spark generation. Deviation in the timing of spark generated due to worn spark plug or faulty ignition coil could adversely affect the engine operation. Moreover, it could also cause an engine misfire in your Volkswagen Jetta. When the ECU detects such malfunctions, it would turn on the check engine light on the dashboard to warn you about the problem. Worn-out spark plug wires could also trigger similar problems.

Faulty mass airflow sensor

A mass airflow sensor measures the amount of air that enters the engine. The ECU uses this data to maintain air to fuel ratio within the cylinder. A defective MAF sensor could destabilize air to fuel ratio within the combustion chamber as a result of which the engine might misfire. Moreover, you might also notice a sudden reduction in the power output. Illumination of the check engine light on the dash of your Volkswagen Jetta is a sign of a faulty MAF sensor. Replace it as soon as possible to keep the engine operational.

Loose gas cap

A loose gas cap or damaged gas cap seal could also turn on the check engine light on the dash of your Volkswagen Jetta. Optimal fuel pressure is really necessary to keep the fuel delivery system operational. A cracked or loose gas cap destabilizes fuel pressure within the fuel lines which could adversely affect the engine operation. When the ECU finds out about such irregularities, it would turn on the check engine light to warn the driver about the problem.

How to fix a check engine light?

Illumination of check engine light on the dash of your Volkswagen Jetta indicates that something is clearly wrong with your vehicle. Negligence could cause irreparable damages to the engine of your vehicle in the long run. So, contact a reputed car service center in your locality to fix the malfunctions in the system as soon as possible.

Sum up

The ECU turns on the check engine light on the dash of your Volkswagen Jetta to warn you about the malfunctions in the system. It should never be neglected. Efforts should be made to identify and fix defects in the system as soon as possible.

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