Causes Check Engine Turns On Without Symptoms on Chevrolet – Ecotec Engines (Spin, Sonic, and Trax) – In this article, we will discuss one of the problems that often occur in Chevrolet cars with Ecotec engines. In this case, I try to convey some of the cases that we have worked on and some of the information from other friends.
Read more: 7+ Main Causes of Check Engine Lights
Causes Check Engine Turns On Without Symptoms on Chevrolet – Ecotec Engines (Spin, Sonic, and Trax)
Chevrolet that uses this type of engine is the Chevrolet spin model with 1,200 CC, Chevrolet Aveo sonic with 1,400 CC, and Trax with 1,400 CC turbo. Although there are slight differences, all three have a similar engine construction. This makes the three types of cars have almost similar problems. Some common problems that often occur start from problems with a leaking water pump, problematic coils, and engine indicators that suddenly appear without any symptoms. Even the check engine does not cause any effect on the engine.
In some cases, the appearance of the check engine indicator is usually accompanied by symptoms of the engine being lame. Or in some cases, reduced engine power due to coil problems. However, if the check engine indicator appears, it is not accompanied by any symptoms or effects. If this happens then you need to take the car to a repair shop. Although there are no symptoms, in this case, I can tell that the car has a problem.
To solve this problem, we can’t just guess. We need to scan the damage with a scanner. In this case, after we do the scan, we often encounter problems with the fuel trim lean fault code. What does it mean if your car has such a fault code?
The meaning of the fault code is that the oxygen sensor reads the fuel-air mixture is too thin or has too much air. This indicates that there is an air leak in the intake system which causes more air to enter the engine than it should. Next, we do an examination of this problem. After we checked, we found out that the leak was coming from the solenoid canister. This is also often referred to as an EVAP purge solenoid. This part has a leak from the inside so it requires component replacement.
How to Find This Problem?
To find out more about the damage to the solenoid canister, we can read the fuel trim data on the scanner. Next, we can see the increase in the value of fuel trim. Normal fuel trim values are close to 0 with a tolerance of -10 to +10. So when the mixture reads lean or more air then the fuel trim value will go past +10 and vice versa.
From this, we can test the solenoid by closing the solenoid channel. If when closed the value read on the scanner is close to 0, it can be ascertained that there is a leak in the solenoid canister. However, if when we close it there is no change, it means that there is another problem that causes more air to enter. From the results of the examination, in this case, we know that the problem originates from the solenoid canister. And we need to do the component replacement.
After replacing and doing a road test the car returned to normal.
Exactly How Does EVAP Work?
One of the most important systems in the engine is a system that is able to minimize exhaust emissions. We call this system an Evaporative Emission Control (EVAP) system. The EVAP system here is different from the existing evaporator A/C system. The EVAP system is a system that functions to prevent fuel vapor or gasoline in the fuel tank from escaping directly into the free air.
As we know that gasoline is a very volatile liquid, and of course, the fuel tank will contain gasoline vapor. Gasoline vapor in the tank must come out so that the pressure in the tank is not too large. However, the problem is that the gas vapor in the tank cannot just escape into the outside air. This is because gasoline vapor contains gases that are very harmful to humans. So the steam requires special handling. That’s why the EVAP system was created. With the EVAP system, the gasoline vapor in the tank flows back into the engine through the charcoal canister which then the steam will be burned along with the engine combustion process.
Read more: ECM vs PCM vs ECU what are the differences?
The EVAP purge solenoid is the component operated by the ECM. When the engine is off, the EVAP purge solenoid will close. Then, when the engine starts and the temperature starts to warm up, the ECM slowly starts to open the EVAP purge solenoid and makes the fuel vapor suck from the charcoal canister and burn it inside the engine. When the gasoline vapor is in the charcoal canister, the gasoline vapor will be mixed with a little air from the outside and the water content is removed so that when it enters the steam engine it is in a clean condition. The entry of gasoline vapor through the EVAP system is monitored by the oxygen sensor. If the flow is too much or too little it will cause the engine indicator to light up.
The problem that usually occurs with the EVAP system is the EVAP purge solenoid that is jammed or leaking. Doing so can cause the engine indicator to light up. In some types of EVAP purge cars that are stuck in an open condition can cause the car to be difficult to start. This mostly happens at the time after filling up with gas. To solve the problem with the EVAP purge solenoid, replace the solenoid component.