Defective AdBlue tanks and faulty NOx sensors cause serious problems in the Citroën Berlingo. Drivers are faced with warning lights, start lockouts and MOT failures. The problem often occurs after 70,000 kilometres and mainly affects diesel models with BlueHDi engines. What is going on here and how do you solve it?
Which Berlingos are vulnerable to AdBlue faults
The diesel versions of the Citroën Berlingo are the most prone to problems with the AdBlue system. This applies in particular to models with the 1.5 HDi, 1.6 HDi and 2.0 HDi engines. These vehicles use an SCR system (Selective Catalytic Reduction) to reduce nitrogen oxides in the exhaust gases. The system injects AdBlue fluid, also known as urea, into the exhaust to neutralise harmful emissions.
In some Berlingos from 2016 to 2020, problems occur without any prior warning. The vehicle then suddenly refuses to start. This is due to design faults in the AdBlue tank and pump.
‘ This counter shows how many more times you can start the engine before the car is blocked. ’
Warning lights and fault codes on the dashboard
When the AdBlue system fails, various lights appear on the dashboard. You will see the engine management light, the AdBlue light and often a countdown timer. This counter shows how many more times you can start the engine before the car is blocked.
Common fault codes are:
- P2200: NOx sensor not responding
- U029D: No communication with the deNOx system
- P20E8: Pressure in the urea line too low
- P2048: Short circuit in the urea injector
- P2BAD and P20EE: Faults in the SCR system
These codes become visible when a garage reads out the car with a diagnostic computer. Sometimes several codes appear at once, indicating a combination of problems.
Why does the AdBlue tank leak on the Berlingo
The Berlingos AdBlue tank has a design flaw. The pump is built into the tank itself, and the circuit board of this pump comes into contact with AdBlue fluid. This leads to corrosion and contamination of the pump type mechanism. In the end the pump fails and the entire tank has to be replaced.
Another common problem is crystallisation. AdBlue consists of urea and water. When it comes into contact with air or low temperatures, hard crystals can form. These crystals accumulate around the injector and in the lines. The system then becomes clogged and can no longer inject the fluid properly.
Sometimes leakage occurs due to overfilling. Excessive pressure in the tank can cause small cracks. Spillage when filling up can also lead to a build-up of crystals around the filler neck, which will eventually damage the tank.
Faulty NOx sensor causes MOT issues
The NOx sensor measures how much nitrogen oxide is coming out of the exhaust. If the sensor is defective, the engine management system receives incorrect information. As a result, the AdBlue system cannot function correctly and emissions increase. This is picked up during the MOT test and the vehicle will fail.
The NOx sensor on the Berlingo has a limited service life. After around 70,000 to 100,000 kilometres, the component starts to fail. Replacement costs around 275 euros, excluding labour. Checks often reveal that as well as the sensor, the AdBlue tank is also defective. In that case, the costs rise significantly.
‘ In the Netherlands, disabling emission control systems is prohibited by law. ’
Costs of repair and replacement
A diagnostic check at the garage costs a few tens of euros. This is a sensible first step to determine exactly what is going on. If only the NOx sensor needs to be replaced, you will pay 200 to 300 euros including fitting.
Replacing the complete AdBlue tank is an expensive repair. The tank itself easily costs 1,200 euros or more. On top of that come labour costs of several hundred euros. In total you should reckon with 1,500 to 2,000 euros. For a commercial vehicle or an older Berlingo this is a substantial investment.
Some owners consider disabling the AdBlue system via an ECU modification (a change to the engine control unit). This removes the emissions control system from the engine software. Be aware: this has consequences for the MOT test and for air quality. In the Netherlands, disabling emission control systems is prohibited by law.
How do you resolve a urea warning
When the urea light comes on, you can follow the steps below. First, top up the AdBlue reservoir with high-quality fluid. Only use approved AdBlue from recognised petrol stations or garages. Filling up at dubious suppliers can actually cause more problems.
Then restart the engine. Sometimes the light goes out by itself after a short drive. The system regularly checks the AdBlue level and the operation of the pump. Drive a few kilometres to give the system a chance to reset itself.
Does the light stay on? Then have a diagnostic check carried out by an authorised Citroën dealer or specialist garage. They can read the fault codes and determine whether the issue concerns a sensor, the pump or the injector. Acting early prevents the problem worsening and your car eventually failing to start.
What can you do to prevent problems
Prevention is better than expensive repairs afterwards. Always use quality AdBlue from reliable sources. Cheap alternatives can accelerate contamination and crystallisation. Never fill the reservoir right up to the brim. Leave a little space to prevent pressure build-up.
Some owners add an anti-crystallisation additive each time they fill up. This helps to prevent a build-up of crystals. This additive costs a few euros per bottle and can save you a lot of trouble. Make sure you only use products that are suitable for AdBlue systems.
Check the AdBlue level regularly and top up before the warning light comes on. When the system runs for a long time with a low level, the pump can be damaged. Also schedule regular diagnostics, especially once your car has more than 60,000 kilometres on the clock. That way, you can spot problems before they lead to start lockouts.
‘ Timely diagnosis and repair saves you a lot of money and prevents you ending up stranded at the roadside with a car that will not move. ’
Do you recognise these problems with your Berlingo
AdBlue faults in the Citroën Berlingo are unfortunately not uncommon. Many owners of diesel models encounter them sooner or later. The combination of design flaws, crystallisation and wear on sensors causes major headaches. The costs can rise sharply, especially when the tank has to be replaced.
Do you recognise the warning signs? Do you see warning lights on the dashboard or notice that the car is harder to start? Then dont wait too long before taking action. Timely diagnosis and repair saves you a lot of money and prevents you ending up stranded at the roadside with a car that will not move.
On the Carnews website you will find more information about common problems with different car brands and practical maintenance tips. Discover how to keep your car in top condition and avoid costly repairs.
Frequently asked questions
The most common AdBlue and urea problems with the Citroën Berlingo are crystallisation of the AdBlue fluid, which clogs lines and the injector and causes the SCR system to work poorly. In addition, the AdBlue pump integrated into the tank and the NOx sensors often fail, causing fault codes and warning lights. Leaks or contamination in the tank and electronics are also common, often resulting in costly tank replacement. These faults frequently lead to codes such as P20E8, P2200, P2BAD and P20EE and ultimately to a start lockout.
Common causes of AdBlue faults in a Berlingo are crystallisation of the fluid (especially when spilt and at low temperatures), a defective AdBlue pump or injector, and failing NOx sensors. These problems often arise due to contamination, leaks in the tank unit and the use of poor-quality or contaminated AdBlue. Prevent faults by using only high-quality AdBlue approved by the manufacturer, avoiding spillage or overfilling and, if desired, adding an anti-crystallisation additive. If warning lights appear, have a diagnostic check carried out in good time to prevent more serious damage.
If an AdBlue error message appears, you can first top up the AdBlue tank with approved AdBlue fluid and restart the engine to see whether the message disappears. Then drive a few kilometres; sometimes the warning light goes out by itself. When topping up, make sure you neither spill nor overfill, and consider using an anti-crystallisation additive with every refill. If the message remains or the engine warning light also comes on, a diagnostic check at a garage is essential.
The average repair costs for AdBlue and urea-related problems with the Citroën Berlingo range roughly from 20200 to more than 202000, depending on the defective component. Replacing a NOx sensor usually costs around 20200d 300300. Replacing the complete AdBlue/urea tank with integrated pump can range from around 201200 to over 202000 including labour. Diagnostic checks generally fall into the category of a few tens of euros.