Peugeot Check Engine Light Stays On | Engine System Faulty

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Illuminated Peugeot check engine light means that there is a malfunction of the engine or emission system. This problem is often caused by a faulty spark plug, ignition coil, mass airflow sensor, oxygen sensor, or a loose gas cap.

In addition to the Peugeot check engine light staying on, you will get an Engine management system fault message displayed on the dashboard on newer models.


Pay attention to how your engine is running. Below is a list of possible symptoms that you may notice.

  • Rough idle,
  • engine judder under acceleration, or lack of power.
  • Peugeot check engine light stays on, and the car won’t start.
  • The car won’t accelerate.
  • Peugeot check engine light flashing.

The BC display may also show messages regarding the engine operation. You can use a YOUCANIC scanner to diagnose your Peugeot check engine light via the OBD port under the dashboard. All 2000 and newer Peugeots have an On-Board Diagnostic (OBD) computer.

Peugeot Check Engine Light Meaning

Here are some of the usual combinations.

  • It is a flashing check engine light with a Catalytic Converter Fault message displayed on the BC. Engine shakes and runs rough. This is a definitive sign of a misfire caused by bad spark plugs or faulty ignition coils. Do not drive the car, as this will cause damage to the catalytic converter.
  • Constant check engine light — The engine is running fine. In most cases, this is caused by emission control system issues. It will probably be either faulty O2 sensors or a worn-out catalytic converter. A loose gas cap can also cause it.
  • Constant check engine light with a Depollution system faulty message is displayed on the BC. The engine is running rough. Now, this is a tricky one. Scan for codes, and you will probably get a P0300 and P1340 code. This is described as a severe misfire on cylinders 1, 2, 3, or 4. This is misleading, as the usual problem is with one of the camshaft position sensors. Further diagnostic by a mechanic is required.
  • Constant check engine light with Engine fault: repair needed message is displayed on the BC. The engine is running fine. This can be a sign of boost or fuel pressure system-related problems.
  • Constant check engine light with Engine fault: repair needed message is displayed on the BC. If the engine has a very rough idle, a high-pressure fuel pump is often a common cause. If it idles fine but lacks power and poor acceleration, there is a large boost leak, or you could have a clogged catalytic converter.

Modern THP engines have a high-pressure fuel injection system, turbocharger, variable valve timing, and variable valve lift.

These are some things that you need to consider when looking into Peugeot engine management light problems.

Common Problems

Whatever the combination, you will need a code reader or a scan tool to understand the problem better. Without it, you can only guess the source of the problem. This hit-and-miss method might end up as a wild goose chase.

How to Diagnose Peugeot Check Engine Light

  1. Plug an YOUCANIC Scanner into the OBD2 port. In most Peugeot vehicles, it is in the driver’s side footwell, under the steering wheel. However, some models have OBD2 ports located in some unusual places. In Peugeot 407 or 607, look in the armrest compartment. In Peugeot 307, 308, or RCZ, there is a small matt-covered slot at the bottom of the central console, in front of the gearbox lever. Remove this matt to reveal the port. In 508, take out the ashtray that is located in front of the gearbox lever.
  2. Turn the ignition ON so that your dashboard illuminates, but don’t start the engine.
  3. Allow your YOUCANIC scanner to turn on. Press Enter, then Read Codes.

How to reset Peugeot check engine light

To reset the Peugeot engine management light, first, you must fix the problem that triggered the fault codes. Then watch the video or follow the instructions below on how to reset the check engine light.

Next, use the YOUCANIC scanner to clear the fault codes via the OBD-II port under the dashboard.

  1. Connect an OBD2 scanner into the port under the dashboard.
  2. Turn on the ignition.
  3. Press enter on your scanner. Scroll down to Erase Codes—press enter.
  4. Turn the ignition off and wait for several seconds.
  5. Turn the engine on and check if the check engine light will appear again.

About Author

I have been working on vehicles for over 20 years. In 2016, I decided to start YOUCANIC so that I can share my expertise with vehicle owners all over the world.