AdBlue is an essential component in modern diesel vehicles, helping to reduce harmful emissions and keep your vehicle compliant with environmental regulations. However, when an AdBlue malfunction occurs, it can be frustrating and, in some cases, prevent your vehicle from starting or operating correctly.
In this guide, we’ll explore the common causes of AdBlue system failures, how to troubleshoot issues, and what steps you can take to fix the problem.
Common Causes of AdBlue Malfunctions
Several factors can contribute to an AdBlue system malfunction, including:
- Low or Contaminated AdBlue – If the AdBlue fluid is low or has been contaminated with dirt, fuel, or other substances, it can trigger a system failure.
- Faulty AdBlue Sensors – Over time, sensors that monitor AdBlue levels and quality can fail, leading to false warnings or system shutdowns.
- Crystallization Issues – If AdBlue is exposed to extreme cold or isn’t used properly, it can crystallize, causing blockages in the system.
- Software Glitches – Sometimes, a warning light stays on even after refilling, indicating a system reset is needed.
- Pump or Injector Failure – The system relies on pumps and injectors to deliver AdBlue into the exhaust. If these components fail, the system won’t function correctly.
What to Do If You See an AdBlue Warning Light?
If your AdBlue warning light appears, it’s crucial to address the issue as soon as possible. Ignoring it could lead to your vehicle entering limp mode or refusing to start. Here’s how to troubleshoot:
- Check AdBlue Levels – Ensure the tank is filled with high-quality AdBlue fluid.
- Inspect for Crystallization – Look for white, powdery residue around the injector or inside the tank.
- Perform a System Reset – In some vehicles, the warning light will remain on until the system is manually reset.
- Scan for Fault Codes – Use an OBD2 scanner to check for error codes related to the AdBlue system.
- Seek Professional Help – If the issue persists, a mechanic can diagnose and replace faulty sensors, pumps, or injectors.
AdBlue Problems in Specific Vehicles
Different vehicles can experience AdBlue malfunctions for various reasons. Here are some common issues for specific makes and models:
Ford Transit: AdBlue Warning Light Issues
Owners of the Ford Transit often report issues with the AdBlue warning light staying on even after refilling. This can be caused by a faulty level sensor or a software issue that requires a reset. Learn how to troubleshoot and fix this issue on our AdBlue warning light Ford Transit page.
Mercedes: AdBlue Sensor Failures
Many Mercedes vehicles, particularly those using BlueTEC technology, suffer from AdBlue sensor failures. This can cause incorrect fluid level readings, leading to unnecessary warnings or system shutdowns. Read more about this issue on our AdBlue sensor Mercedes page.
Peugeot: AdBlue Light Still On After Filling
If you drive a Peugeot and your AdBlue light remains on after refilling, you may need to manually reset the system. Some models require a specific procedure to clear the warning message. Get step-by-step guidance on our AdBlue light still on after filling Peugeot page.
Crystallization Issues: What You Need to Know
AdBlue can crystallize under certain conditions, leading to blockages in injectors, pumps, and filters. This is a common issue in colder climates or when AdBlue isn’t stored properly. Learn how to prevent and fix this issue on our AdBlue crystallization problems page.
Resetting the AdBlue Warning Light
If your AdBlue warning light doesn’t turn off, a system reset may be required. Different vehicles have different reset procedures, which may involve using diagnostic tools or performing specific ignition cycles. Get a full guide on our how to reset AdBlue warning page.
Preventing Future AdBlue Malfunctions
To avoid costly repairs and frustrating breakdowns, follow these simple maintenance tips:
✅ Use High-Quality AdBlue – Only use certified ISO 22241 AdBlue to prevent contamination.
✅ Refill Regularly – Don’t wait for the warning light; top up your AdBlue fluid regularly.
✅ Store AdBlue Properly – Keep it in a cool, dry place away from extreme temperatures.
✅ Check for Leaks and Crystallization – Regularly inspect the AdBlue system for any white residue or leaks.
✅ Service Your Vehicle – Follow the manufacturer’s guidelines for AdBlue system maintenance.
Final Thoughts
AdBlue malfunctions can be a headache, but with proper care and troubleshooting, most issues can be resolved quickly. Whether your AdBlue warning light won’t turn off, you’re dealing with sensor failures, or you suspect crystallization, there are solutions available.
For more in-depth guides on specific AdBlue problems, check out our detailed pages linked above. Stay proactive, and keep your diesel vehicle running smoothly! ??
