If your Peugeot AdBlue warning light is still on even after refilling, you’re not alone. Many Peugeot drivers experience this issue, which can lead to frustration and, in some cases, prevent the car from starting.
In this guide, we’ll cover:
✔️ Why your AdBlue warning light stays on after refilling
✔️ How to reset the AdBlue fault on a Peugeot
✔️ What to do if your Peugeot won’t start due to an AdBlue issue
Why Is the AdBlue Light Still On After Filling in a Peugeot?
Even after adding AdBlue to your Peugeot, the warning light may remain on due to several reasons:
- The system hasn’t recognized the refill yet – Some models take time or require a reset.
- The AdBlue quality sensor detected contamination – Poor-quality AdBlue or contamination can cause faults.
- There’s a crystallization blockage – AdBlue can crystallize in the injector, pump, or tank.
- The NOx sensor or AdBlue injector is faulty – If these components fail, the system may not function properly.
- A software glitch requires a reset – Some Peugeot models need a manual or diagnostic reset.
Ignoring this warning could result in engine restrictions or even a no-start condition if the system believes AdBlue is empty.
How to Fix the Peugeot AdBlue Warning Light Stuck On
If the AdBlue warning light won’t turn off after refilling, try the following troubleshooting steps:
1️⃣ Drive for a Few Miles
Some Peugeot models require driving a few miles after a refill before the system detects the new fluid and resets the warning light automatically.
2️⃣ Perform a Manual Reset
If the light remains on:
- Turn the ignition on (but don’t start the engine).
- Press and hold the gas pedal for 10-15 seconds.
- Turn off the ignition and wait a few minutes.
- Restart the car and check if the warning light is gone.
3️⃣ Use an OBD2 Scanner
If the manual reset doesn’t work, plug in an OBD2 diagnostic scanner to check for error codes and manually reset the AdBlue system.
4️⃣ Check for AdBlue Crystallization
? Look for white, powdery residue around the AdBlue injector, pump, or tank. If crystallization is present, it may block the system and prevent it from recognizing the refill. A mechanic may need to clean or replace the affected components.
5️⃣ Check the AdBlue Pump and Injector
A failing pump or blocked injector can prevent the system from injecting AdBlue properly, leading to a persistent warning light. If the system doesn’t detect proper flow, the error will stay on.
6️⃣ Perform a Hard Reset (Battery Disconnect Method)
- Turn off the ignition and remove the key.
- Disconnect the car battery for 10-15 minutes.
- Reconnect the battery and start the vehicle.
- Check if the AdBlue light is now reset.
? Warning: Disconnecting the battery may reset other vehicle settings, such as the radio and clock.
7️⃣ Seek Professional Diagnosis
If none of the above methods work, a Peugeot dealer or mechanic may need to perform a software update or replace a faulty AdBlue sensor, pump, or NOx sensor.
How to Reset the AdBlue Fault on a Peugeot
Some Peugeot models allow you to reset the AdBlue system manually. Here’s how:
Method 1: Basic Reset Procedure
- Refill the AdBlue tank with at least 4 liters of fluid.
- Turn the ignition on for 30 seconds without starting the engine.
- Turn off the ignition and wait a few minutes.
- Start the engine and check if the warning light disappears.
Method 2: OBD2 Reset (Diagnostic Scanner Required)
- Connect an OBD2 scanner to the vehicle.
- Check for error codes related to the AdBlue system.
- Clear the codes and restart the car.
- Drive for a few miles to allow the system to recalibrate.
Method 3: Battery Disconnect Reset
- Disconnect the negative terminal of the car battery for 10-15 minutes.
- Reconnect it and start the vehicle.
- Check if the AdBlue warning light has been reset.
How to Prevent Future AdBlue Issues in a Peugeot
✔️ Use High-Quality AdBlue – Only use ISO 22241-certified AdBlue to prevent contamination.
✔️ Refill Before the Warning Light Appears – Don’t wait until it’s almost empty.
✔️ Store AdBlue Properly – Keep it in a cool, dry place to prevent crystallization.
✔️ Regularly Check for Crystallization – Look for white deposits around the injector and pump.
✔️ Schedule Regular Servicing – Have a mechanic inspect the SCR system, AdBlue pump, and NOx sensors during routine maintenance.
Final Thoughts
A Peugeot AdBlue warning light staying on after refilling is a common issue, but it’s usually fixable. Try driving for a few miles, performing a reset, or using an OBD2 scanner to clear the error. If the issue persists, a professional diagnosis may be needed to replace faulty sensors, fix blockages, or update the vehicle software.
? Still having trouble? Don’t ignore the warning—fixing it early can prevent expensive repairs and avoid a no-start condition. Stay ahead of AdBlue problems and keep your Peugeot running smoothly!
