Error message and problems with DPF regeneration in Mercedes ML Class 2008 - suspected cause: Ad-Blue system pressure

Hey, I drive a 2011 Mercedes GLK Class and had exactly the same problem some time ago. In my case it was definitely the Ad-Blue system, the pressure was too low. I had to go to the garage and it turned out that the Ad-Blue tank was defective. It was a pretty serious matter, because without a functioning Ad-Blue system, the exhaust gas purification system doesn't work properly and you might not pass the MOT. They replaced parts of the tank and resealed the system. It wasn't exactly a minor repair, but everything worked perfectly again afterwards. Hope that helps you. Take care of yourself!

(Translated from German)

Thank you for your feedback. It does sound like it could be similar for me. Can you remember what you ended up paying for the repair? And have there been any other problems since then or has everything been running smoothly since the repair? I'm just trying to mentally prepare myself for the next workshop visit... Looking forward to your reply! Stay healthy!

(Translated from German)

Hey, no problem, I'm glad if I can help. Well, the repair for the Ad-Blue tank was a bit more expensive. For me it was a total of €1620. Since I got the car back from the mechanic, the problem with the low pressure in the Ad-Blue system has been solved. No more indicator lights and the DPF regeneration works perfectly again. So from my point of view, everything is great! So you don't have to stress yourself too much, we're all only human. Good luck with your visit to the workshop and stay healthy!

(Translated from German)

That's a lot of money, but it sounds like it was worth it to get the problem fixed. I'm relieved to hear that everything has been going well since then! Thanks for your support and reassuring words. You've eased my anxiety about the next mechanic visit. I'll see how it goes for me. You're right, we're all only human and make the best of the circumstances we're given. Thanks again and take good care of yourself!

(Translated from German)

Hello everyone, since yesterday my car reports Adblue problem. And now today it says no start in 800km, and that the km runs down when I continue driving naturally. This has started since I filled up the Adblue too full. Any tips!!!

(Translated from German)

Hi Peter, overfilling the AdBlue tank can cause issues. The first step would be to check if there's any AdBlue leakage. If you don't see any leakage, it's possible that the AdBlue system sensor is giving a false reading due to overfilling. You might need to drain some of the AdBlue out to get it back to the correct level. If the problem persists, I would recommend taking your car to a mechanic as soon as possible, as driving with an AdBlue issue can lead to bigger problems. Please keep us updated on your progress. Do you have any other questions?

Hi! I have a 2018 Mercedes GLC220 diesel. A short time ago, my engine light came on. After troubleshooting, it showed that the NOx sensor behind the engine was defective. I replaced the NOx sensor, and a Mercedes workshop calibrated it. After two days, the light came back on. I'm having trouble refilling AdBlue; could it be an airlock? The tank gauge shows almost empty, showing red, and the display shows that I can drive 1170 miles. Reset the AdBlue system? What do you think?

(Translated from Norwegian)

It's possible that an airlock or a sensor issue is causing the incorrect AdBlue level reading. First, try refilling the AdBlue tank slowly to ensure there are no air pockets. If the problem persists, it might be necessary to reset the AdBlue system, which can sometimes be done using a diagnostic tool. If you're not comfortable doing this yourself, I recommend visiting a mechanic to ensure the system is properly reset and to check for any other underlying issues. Let me know how it goes or if you have any further questions!