When the messages "Check injection system" and "Check anti-pollution system" appear along with the engine warning light on your Renault, this may indicate a malfunction in the engine or emissions control system.
These alerts are often accompanied by the anti-pollution warning light — a common orange engine symbol — frequently seen on models like Renault Clio, Mégane, Captur, and Scénic. Don’t panic — here’s how to understand these messages and take action quickly.
How should you react when the “engine fault” message appears?
- If the engine seems to be running normally and you don't feel any power loss, you can keep driving cautiously to a garage. However, don’t delay the diagnosis, as issues related to the injection system can quickly worsen.
- If you experience jerking, power loss, or irregular engine running, stop the vehicle as soon as possible. These symptoms often point to serious problems with the fuel injectors or Diesel Particulate Filter (DPF), requiring immediate intervention.
- On diesel versions of the Kadjar, the DPF and EGR valve are frequent causes of the “Check anti-pollution system” message. If the vehicle continues to operate normally, you can head to a garage, but any power loss should alert you.
Most common causes of these messages
These messages appear when the Engine Control Unit (ECU) detects a fault affecting combustion or emission reduction. Here are the most common causes:
Injector issues
Fuel injectors deliver the precise amount of fuel into the cylinders. If one or more injectors are clogged or faulty, this can lead to poor combustion, triggering the "Check injection system" message and possibly the anti-pollution warning light.
Cleaning or, in more severe cases, replacing the injectors may be necessary. An OBD-II diagnostic scan can identify the faulty injector.
Are you looking for a car scanner ?
- My model is not in the list
I don't have any lights on
Clogged EGR valve
The EGR (Exhaust Gas Recirculation) valve helps reduce emissions by recirculating a portion of exhaust gases back into the engine. It often gets clogged, especially with short trips or city driving, which can trigger the "Check anti-pollution system" message on models like the Renault Scénic or Clio.
Diesel Particulate Filter (DPF) issues
On diesel models like the Mégane or Kadjar, the DPF is key to reducing emissions. If it's clogged, the engine may not run properly, leading to the "Check anti-pollution system" message and the illumination of the anti-pollution warning light.
Faulty sensors
Sensors such as the fuel pressure sensor or exhaust gas temperature sensor may send incorrect data, causing error messages and triggering the anti-pollution warning light.
How to identify the source of the problem?
Use an OBD2 diagnostic scanner
Renault vehicles are equipped with OBD2 diagnostic ports, allowing you to connect a Car Diagnostics Scanner to read specific fault codes. These codes will help pinpoint the faulty component.
If you have an OBD scanner, you can do this yourself. Otherwise, a mechanic can perform the diagnostic for you.
Visit a professional
If you don’t have a diagnostic scanner or don’t know how to interpret the results, it’s best to consult a professional or a Renault garage. They can provide an accurate diagnosis and a quick solution.
How to turn off the anti-pollution warning light and “Check injection system” message?
After fixing the root cause of the “Check anti-pollution system” or “Check injection system” messages, you may need to reset the warning light. Here's how to do it:
Use an OBD-II diagnostic scanner
The most reliable way to turn off the anti-pollution warning light is by using an OBD-II diagnostic scanner. This tool lets you read and erase fault codes once the issue is resolved. Connect the scanner to your Renault’s OBD port, clear the error codes related to injection or emissions system, and restart the vehicle to check if the warning light disappears.
Disconnect the battery
If you don’t have a diagnostic scanner, an alternative method is to disconnect your vehicle’s battery for about 10–15 minutes. This can sometimes reset the system and turn off the warning light. However, this is only a temporary solution and does not guarantee the issue has been fixed.
Are you looking for a car scanner ?
Let the system reset itself
If the fault was minor (such as a temporary issue), the warning light may go off by itself after several engine start cycles, once the system confirms everything is working correctly.