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Vehicles such as Onix, Spin, Cobalt, Prisma and Tracker face recurring defects in the Chevrolet line that do not appear on the scanner, challenging mechanical professionals to find the solution.
The automotive universe is not immune to hidden problems, and the Chevrolet line seems to be facing one of those defects that drives mechanics crazy. Owners of popular models like Onix, Spin, Cobalt, Prisma and Tracker are reporting faults that make the car shake at idle, without any error warning in the diagnostic systems. The situation is so complex that, in some cases, the vehicle even cuts the engine, depending on the conditions of use. And the worst part: no fault code is recorded on the scanner, making the technicians' lives even more complicated.
Mysterious problem in Chevrolet lineup defies traditional diagnoses
The mechanics have been racking their brains to identify the root of the problem. According to the specialist from DR Auto Mecânica, interviewed by CPG (Click Petróleo e Gás), the defect has been observed frequently in the models of Chevrolet line, Especially Onix, Spin, Cobalt, Prisma and Tracker. “The car oscillates, fails and, even with the analysis via scanner, no error code appears. It is a real nightmare for any professional in the field”, he states.
First steps of diagnosis: battery and cables
One of the first points investigated is the battery, which may be below 60% capacity and cause system failures, especially in automatic models. In addition, spark plug wires and coil are analyzed with the help of an oscilloscope to check for possible misfires. “Even after replacing components such as cables and coils, the symptoms continue. This ends up forcing us to look deeper into the air and fuel system,” explains the mechanic.
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The invisible cause: canister valve and its complications
Another critical point in this diagnosis is the canister valve, located in the intake manifold in some models, such as the Onix and the Prism. “Even after replacing the valve, the problem may persist, because many people don’t know that the valve needs to operate precisely, correctly locking and releasing the flow of gases,” details the expert. In these cases, the presence of damaged activated carbon can compromise the functioning of the valve, causing it to become blocked and consequently fail.
Furthermore, the habit of overfill the fuel tank can make the problem worse by allowing fuel to enter the canister system, damaging the activated carbon filter and causing even more complications. “When the canister starts receiving fuel, instead of just vapor, the activated carbon dissolves, and this destroys the valve,” he warns.
Faults not recorded by the diagnostic system
One of the biggest frustrations for mechanics is the lack of fault codes on the scanner. “The system does not indicate any defect, but the car starts to lose its fuel reference. When filling up with gasoline, it continues to recognize it as if it were alcohol, which generates a lean mixture and causes failures.” This explains why many drivers only notice the problem when they change fuel.
How to solve this problem that is making mechanics' hair stand on end?
Replacing the canister valve may be unavoidable, but the key is to understand the context: check that the activated carbon is not dissolved in the system and avoid overfilling the tank. These precautions can prevent the problem from reappearing, avoiding unpleasant surprises.
For those who are dealing with this headache, here's a tip: pay attention to your vehicle's behavior, especially when refueling, and remember to always perform complete maintenance on the air and fuel system.
Now, we want to know: have you ever had similar problems with your Onix, Spin, Cobalt, Prisma or Tracker? Share your experience and help other readers understand what might be happening with their vehicles!
The Prisma car when it stops accelerating a little it looks like it is failing and it shakes until third gear then it goes back to normal.
My 2015 prism is like that too
I know it's not on the list, but I had a 2009 Celta that wouldn't accept it at all when switching from gasoline to alcohol, to the point where I had to tow it out of the house.
I had a 2010, I filled up with ethanol when the tank ran on gasoline, the control unit didn't recognize it and turned off the car, it only came out on a tow truck.
This is normal in any flex car,
When changing the fuel, you need to drive the car for at least 20 km to give the system time to read the combustion and adjust.
Then you can relax.