If you drive a Peugeot 308 diesel, chances are you’ve seen it: that little UREA warning light staring back at you from the dashboard like a reminder you forgot to text someone back. It’s not dramatic. It’s not flashing red panic. But it does matter.

Today, we’re going deep—really deep—into everything you need to know about the Peugeot 308 urea light reset, from what triggers it, to how to reset it properly, to when it signals something more serious than low AdBlue.

Let’s break it down calmly, clearly, and step-by-step.

What Does the UREA Light Mean in a Peugeot 308?

The UREA light is connected to your car’s AdBlue (DEF) system. Urea solution—marketed as AdBlue—is injected into the exhaust system to reduce harmful NOx emissions.

When the light comes on, it usually means one of three things:

• The AdBlue tank is low.
• The AdBlue system has detected a fault.
• The vehicle needs a reset after refilling.

It’s not just a suggestion. If ignored, your 308 may refuse to start after a certain mileage countdown.

Understanding the AdBlue System in the Peugeot 308

Modern diesel versions of the Peugeot 308 use Selective Catalytic Reduction (SCR) technology.

How SCR Works

1. Diesel engine produces NOx gases.
2. AdBlue is injected into exhaust gases.
3. Chemical reaction converts NOx into nitrogen and water vapor.
4. Cleaner emissions exit the tailpipe.

Think of it as your engine’s environmental conscience.

Why the UREA Warning Appears

Let’s get specific. Here are the main triggers:

1. Low AdBlue Level

• Usually appears with a mileage countdown (e.g., 1500 miles until no start).
• Simple refill required.

2. Faulty NOx Sensor

• The system detects improper emissions control.
• May trigger engine management light too.

3. AdBlue Pump or Injector Issue

• Crystallization can block injectors.
• Tank heating system can fail in cold climates.

4. Software Glitch

• Sometimes the tank is full… but the car doesn’t recognize it.
• Reset required.

Can You Drive With the UREA Light On?

Short answer? Yes… but temporarily.

Long answer? The car will eventually refuse to start once the countdown hits zero.

You’ll see messages like:

• “Top up AdBlue: Starting prevented in 600 miles”
• “Engine start impossible”

That’s not a bluff. It means business.

How to Refill AdBlue in a Peugeot 308

Most Peugeot 308 models have the AdBlue filler:

• Inside the boot under the floor
• Or near the fuel filler cap (blue cap)

Step-by-Step Refill Process

1. Turn off ignition.
2. Open AdBlue cap.
3. Use proper AdBlue bottle with nozzle.
4. Pour at least 5 liters (minimum required for reset).
5. Close cap securely.
6. Wait before restarting.

Pro tip: Don’t just add one liter. The system often requires a minimum refill quantity to clear the warning.

Peugeot 308 Urea Light Reset: The Correct Method

Now we’re at the heart of it.

Method 1: Automatic Reset After Refill

After adding sufficient AdBlue:

• Switch ignition ON (engine off).
• Wait 30–60 seconds.
• Start engine.
• Drive for 5–10 minutes.

In many cases, the light disappears automatically.

Method 2: Ignition Cycle Reset

If the light remains:

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1. Turn ignition off.
2. Lock vehicle.
3. Wait 5 minutes.
4. Unlock and restart.

This allows system recalibration.

Method 3: Diagnostic Tool Reset

If the warning persists, you may need:

• OBD2 scanner
• Peugeot-compatible diagnostic software

A proper scan can:

• Clear fault codes
• Reinitialize AdBlue system
• Reset NOx sensor adaptation

Sometimes the light isn’t about fluid level—it’s about stored fault data.

When the UREA Light Won’t Reset

Here’s where it gets serious.

If you’ve:

• Added more than 5 liters
• Waited proper reset time
• Driven the vehicle

And the light remains, it may indicate:

• Faulty AdBlue tank module
• Crystallized injector
• Defective NOx sensor
• SCR system malfunction

At this point, a diagnostic scan is mandatory.

Common Fault Codes Linked to UREA Warning

Here are codes frequently seen in Peugeot 308 diesel models:

• P20E8 – Reductant pressure too low
• P204F – Reductant system performance
• P2200 – NOx sensor circuit
• P2BA9 – NOx exceedance

Each code points to a specific component.

Peugeot 308 Generations and Urea System Differences

The second-generation 308 (T9, 2013–2021) and later models have slightly different system layouts.

BlueHDi engines are the most common with SCR systems.

Earlier diesel variants without BlueHDi may not use AdBlue at all.

How Long Does AdBlue Last in a Peugeot 308?

Typically:

• 10,000 to 15,000 km per tank
• Depends on driving style
• More highway = less consumption

Aggressive city driving increases usage.

Can You Manually Reset the UREA Light Without Refilling?

No. And we don’t recommend trying to “cheat” the system.

The ECU monitors:

• Tank level sensor
• Pressure readings
• Injection cycles

If fluid isn’t present, it knows.

Trying to bypass the system can:

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• Trigger limp mode
• Damage SCR system
• Cause legal emission issues

Preventing Future UREA Light Issues

Let’s be proactive.

Maintenance Tips

• Top up AdBlue every service.
• Use high-quality AdBlue only.
• Avoid contamination.
• Don’t let tank run completely empty.
• Drive occasionally at highway speeds.

Think of AdBlue like hydration. Don’t wait until you're exhausted to drink water.

Cost of Fixing a Persistent UREA Light

If it’s just fluid? Cheap.

If it’s hardware? Not so much.

Estimated costs:

• AdBlue refill: low cost
• NOx sensor replacement: moderate
• AdBlue tank module: high
• SCR injector replacement: moderate

Ignoring it can escalate repair costs quickly.

Is It Safe to Ignore the UREA Warning?

Temporarily? Maybe.

Long term? Absolutely not.

Besides potential no-start condition, driving with malfunctioning SCR can:

• Increase emissions
• Fail inspection
• Damage catalytic system

Your 308 is smarter than it looks. When it warns you, listen.

Quick Checklist: Peugeot 308 Urea Light Reset

Before panicking, ask:

• Did we add at least 5 liters?
• Did we wait 60 seconds before starting?
• Did we drive for 10 minutes?
• Did we cycle ignition?
• Have we scanned for codes?

If yes to all and the light remains — time for diagnostics.

Final Thoughts: Mastering the Peugeot 308 Urea Light Reset

The UREA light isn’t an enemy. It’s a messenger.

Most of the time, it’s simply asking for AdBlue. Sometimes, it’s warning of a deeper SCR issue. Either way, resetting it properly ensures your Peugeot 308 stays reliable, efficient, and emission-compliant.

Treat it like a gentle nudge—not a catastrophe.

Stay ahead of it, and it won’t surprise you.

FAQs About Peugeot 308 Urea Light Reset

1. How long does it take for the UREA light to go off after refilling?

Usually within 5–10 minutes of driving, if sufficient AdBlue was added.

2. Can I use any brand of AdBlue?

Yes, as long as it meets ISO 22241 standards.

3. What happens if AdBlue runs completely empty?

The car will prevent engine start after countdown reaches zero.

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4. Can cold weather affect the UREA system?

Yes. Frozen AdBlue or heater faults can trigger warnings.

5. Does petrol Peugeot 308 have a UREA light?

No. Only diesel BlueHDi models use AdBlue systems.

If you want to know other articles similar to Peugeot 308 Urea Light Reset: Complete Step-By-Step Guide you can visit the category Service and Parts.