Depollution System Faulty

Peugeot 307 Depollution System Faulty [Common Causes]

In this article, I am going to explain to you what “Depollution system faulty” mean on your 307, the main causes, and what to do in order to solve the problem. let’s get to it

What Does “Depollution system faulty” mean on a Peugeot 307?

In short, the Depollution system faulty is a generic error code that indicates a problem with the engine management system.

Peugeot 307 cars are fitted with an onboard self-diagnostic system called the Depollution System.

This system monitors the engine and identifies any issues that may affect the vehicle’s performance or safety. Typically, a “Depollution System Faulty” message is displayed when the system detects there is something wrong with the car.

What Causes Peugeot 307 Depollution System Faulty

Depollution is a generic fault code that Peugeot uses to tell you something’s wrong with your car, but it doesn’t tell you what specifically. Based on my personal experience as a mechanic I will highlight a few common for this fault.

1. Ignition Coils & Spark Plugs:

The ignition coils and spark plugs are a part of your car’s engine that helps it start up when you turn the key. If either of these components is malfunctioning, it could cause the “Depollution System Faulty” message to appear on your dashboard.

Other symptoms of bad coils or/and spark plugs include engine misfire, rough idling, vehicle shaking and loss of power when accelerating. If you haven’t serviced your Peugeot in a while then it’s likely you need new plugs and coils.

2. Bad Crank Sensor:

Crank sensors are used to read the speed of your engine’s crankshaft. Crank sensors can fail over time and cause issues like a car not starting, or running roughly once it does start.

The “Depollution System Faulty” message can also appear on your dashboard if your crank sensor is malfunctioning. This is another common cause from my experience.

3. Dirty Fuel Filter:

Another common cause for this problem on a Peugeot 307 is a dirty fuel filter. The fuel filter can become clogged with dirt and particles in your petrol, which then prevents the engine from starting and running as it should.

I recommend that you check this as well especially if you are getting fuel pressure-related codes on an obd2 scanner.

4. Bad Coolant Temperature Sensor:

One Peugeot 307 that came to my workshop had a depollution system fault, but then I noticed the coolant temp gauge is really high but the vehicle is not overheating.

I suspected that the coolant temperature sensor was bad and it was. As soon as I replaced the sensor the depollution system fault went away after I cleared the codes.

5. Dirty Fuel Injectors:

Fuel injectors are an important part of your Peugeot engine and they are responsible for putting the right amount of fuel into your engine.

Dirty fuel injectors can cause poor gas mileage, rough idle, hesitation when you accelerate, and the dreaded depollution system fault message.

I recommend cleaning them at least every other oil change or at least once a year.

6. Clogged Catalytic Converter:

A catalytic converter is responsible for removing harmful pollutants from your exhaust. It does this by converting them into carbon dioxide, water vapor, and nitrous oxide.

If your catalytic converter is clogged it can cause the depollution system fault message to appear on your instrument cluster.

7. Bad Oxygen Sensors:

The oxygen sensors are responsible for monitoring the exhaust gas to determine if it is lean or rich. When one of these sensors fails, the car will think that there is no oxygen present in your exhaust and begin to run rich.

This can cause the ECU of your Peugeot to think there is something faulty with the whole exhaust system.

How to Reset the Depollution system faulty on a Peugeot 307

Now that you know the main causes (There are more not mentioned here), Lets look at how you can fix and reset the message on your 307.

Since this fault message is generic, I recommend you get an obd2 scanner I recommended a Peugeot planet or diagbox OBD2 scanner since this is specifically made for Peugeot vehicles and will allow you to reset the fault code and clear all DTCs on your 307.

If you don’t want to diagnose the issue yourself then you can take your 307 to a Peugeot dealer and have them diagnose and reset your fault code. However, don’t expect it to be cheap as Peugeot dealerships tend to charge more than other garages.

Scanning for codes will throw out the exact fault codes and the fault codes will tell you exactly what is wrong with your 307.

If you want to save money on repairs then I recommend getting an OBD2 scanner, like the one I recommended above, and diagnosing the issue yourself.

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