4 Common Causes of Check Engine Lights

4 Common Causes of Check Engine Lights

The Check Engine Light (CEL) is one of the most commonly illuminated indicator lights on any given vehicle. This light can illuminate when there are one or more errors, as reported by a vehicle’s diagnostics, present with the performance of a car.

The problem with this check engine light is that it is as common as it is misunderstood. The number of conditions that can make present are in the hundreds of thousands, which in turn can make diagnosing this check engine light one of the most difficult things for car owners and mechanics alike.

Let’s explore some of the reasons that your Check Engine Light may be illuminated to understand what may be involved in fixing the underlying problems.

1. Emissions Control System Malfunctions

One of the most common reasons the Check Engine Light becomes present involves your car’s Emissions Control System. Cars manufactured in and after 1996 tend to have this problem because of the way earlier OBD II systems and aging emissions control hardware malfunctions.

The reason emissions systems tend to be the cause of CELs revolves around their multiple points of failure.

In Mazdas, particularly MX-5s and RX7s manufactured between 1996 to 2001, something as simple as a dirtied EGR valve can cause the CEL to illuminate. This is because these engines tend to be smaller and more prone to carbon build-up when placed in stop-and-go traffic on a regular basis.

In other models of cars, something like a failed oxygen sensor after the catalytic converter or a failing catalytic converter itself can cause the CEL to illuminate. Replacing either of these components can involve welding and electrical splicing, which is why do-it-yourself mechanics tend to be better served by taking it to a shop that specializes in emissions repairs.

Diagnosing CEL lights involving the emissions control systems of a car requires experience or a hefty wallet to try many fixes.

2. Failing Brake Systems

Another system that experiences failures that causes illuminated CEL is the brake system. Everything from low fluid levels in the lines to unevenly worn brake pads can cause this light to illuminate.

In Chevrolet pickups from 2001 to 2009, this problem is particularly frequent because of the heavier hauls and increased wear on the brake system. If the vehicle is equipped with ABS, this system may produce errors because of uneven wear on the brakes caused by warped rotors, damaged calipers or problematic suspensions.

The best way to fix these problems is to have a mechanic diagnose them. Brake systems can be challenging not because they are complicated, but because they are integral to the proper operation of your vehicle. An improper repair to the brake calipers can, for example, cause the brakes to drag on rotors, which can cause lowered fuel economy and increased wear on the transmission.

3. Ignition Malfunctions

Ignition malfunctions are another common cause of CELs. These may range from simple misfires to more complicated problems that could lead to the inevitable complete failure of a vehicle’s engine. Lights involving ignition malfunctions tend to be some of the more important ones to have promptly diagnosed and fixed.

Honda sedans tend to encounter ignition systems problems as they age. Their problems tend to be related to electrical system malfunctions that can include worn spark plugs and spark plug wires. Their fixes are relatively simple and inexpensive, but it is possible to for worn seals, gaskets and vacuum lines to also be the cause of ignitions malfunctions in these vehicles.

The best way to fix ignition systems malfunctions is to visit a trusted mechanic. Anything less could result in hefty bills after being stranded on the side of the road.

4. Malfunctioning ECUs

In a worst-case scenario, a malfunctioning ECU may be the cause of a CEL This case is unique in that the ECU of a car controls everything from ignition timing to the fuel pump. This system failing is also one of the hardest to diagnose, as there tends to be few diagnostic tools for diagnosing the failure of what is essentially the car’s entire diagnostic system.

Lexus cars tend to be vulnerable to ECU issues because of the high amount of work that has gone into designing diagnostics that help both mechanics and drivers. When these ECUs fail, they can cause erratic problems that can result in problems accelerating to the complete inability to start the car.

Check Engine Lights are Nothing to Ignore

Some mechanics may say that Check Engine Lights are only a feature that can be ignored until your vehicle experiences more serious issues, but we know otherwise at Triangle Car Care.

At the first appearance of a Check Engine Light, you should have your car inspected. We can run on board diagnostic testing that can help read error codes and begin the process of deducing what is wrong with your vehicle.

Once the problem has been identified, it is easy for our mechanics to reliably and succinctly fix.