Even the most attentive driver can be surprised. Unlike cars from the last century, which relied on simple indicators such as an ammeter, oil pressure indicator or overheating light, today's cars are equipped with complex electronic engine control systems. These systems have the ability to self-diagnose and it is they who light up the famous yellow Check Engine light.
However, as expert Revins explains, you should not rely entirely on this pictogram. Its scope is limited, and its warning color is yellow, not forbidding red, which is already the first hint.
There is an error, but the light is silent
The modern engine control system “sees“ even short-term deviations from normal parameters, but does not always alarm them. If the problem is fleeting and quickly recovers, the lamp will not light up. The system will store the error, but will leave the driver in the dark.
Only when the deviation is significant and prolonged, the light is activated. Often this is also associated with a noticeable deterioration in engine performance, which you cannot miss:
When starting: Difficult starting, the engine stalls immediately.
When idling: Unstable rpm, strong vibrations, interruptions.
When driving: Loss of power, increased fuel consumption, interruptions, sudden stops when reducing speed.
What to do?
If any of these symptoms are present, diagnostics are mandatory. If you are not technically literate, your way is to the service station.
More advanced enthusiasts can use an ELM 327 diagnostic adapter, which connects to the easily accessible OBD-II port of any modern car. Using a smartphone application, you can read the errors stored in the memory.
Tip: Take a screenshot of the list of errors, then try to reset them. If they appear again immediately or very quickly, the problem is serious and cannot be postponed. Relatively easy tasks to perform independently are replacing spark plugs, ignition coils or some sensors. Everything else, especially leaks in the intake tract, requires the intervention of a professional.
The mechanical secrets of the engine
The biggest problem with “Check Engine“ is that electronics are not omnipotent. It will not warn you about a number of potential purely mechanical malfunctions that can lead to serious accidents:
Pre-failure condition of the drive belt (which rotates the water pump, generator, hydraulics).
Pre-failure condition of the timing belt. Its breakage in most engines means expensive repairs with valve replacement.
Wear of the cylinder-piston group and drop in compression.
Imminent bearing failure and other problems associated with wear of metal parts.
Other lamps – potential trap
Some red indicators that prohibit further movement can also be “insidious“. Imagine that the brake fluid level drops just a little below the lower mark – the bright red brake system malfunction light comes on. At this point, if a traffic police officer stops you, he or she has the legal right to stop your car from moving, even though you have a spare and can drive away.
Important: In such situations, if you are sure that the system is working correctly, you can take extreme measures, such as temporarily disabling the brake fluid reservoir sensor or restarting the engine, but this should always be an exception and not become a habit. The same applies to the steering failure indicator. In the event of a problem with the electric power steering, if you are literate, you can remove its fuse, which eliminates the risk of towing the car, although steering becomes difficult.
To avoid worries about hidden damage, we recommend that you visit a car service for diagnostics at least once a year, and preferably twice – before the winter and summer seasons. Only a thorough inspection can uncover those problems that your car's electronics are stubbornly silent about.