Q: 335d p20ee code, SCR metering valve cleaning

asked by on October 24, 2017

How hard is it to clean the SCRA metering valve? My ses light is on and the code is p20ee and I was told this valve is probably clogged with urea crystals.

My car has 113000 miles.
My car has an automatic transmission.

The valve is accessible but testing, which is performed coincident to cleaning, requires a BMW specific bi-directional scan tool. The scan tool is used to remotely actuate the valve to see if it is even working. There are other causes of the trouble code that you are writing in about, namely a faulty NOx sensor, issues with the diesel exhaust fluid storage and the selective catalyst reduction (SCR) catalyst itself could be degraded. To obtain a quote for both cleaning and inspection, please use YourMechanic’s service request page. If you have further questions, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I use the front and rear cup holders?
You have two cup holders in the front of the car, and another two for the second row seat. These provide a safe, convenient way to carry drinks with you. The third row seats (if equipped) do not have cup...
How do I extend the seat belt?
If your seat belt is not long enough to safely and properly buckle around you, you will need to get a seat belt extender, which adds eight inches to the seat belt length. To receive a seat belt extender, visit...
Clutch noise
Without being able to hear the noise it will be hard to suggest a cause and repair. A common issue is the dust cover on the transmission. The noise will sound like a rattling and then go away once the...
Blown head gasket or timing chain?
Hello. This is definitely an internal engine problem. When it gets hot the cylinder head fails and this occurs. It can even be a cracked head or block in some serious cases. Either way, the timing chain should be replaced...
High voltage alternator
Most alternators have a voltage regulator integrated within them. This voltage regulator is responsible for making sure that the battery is charged right around 14 volts. If your alternator is producing 17 volts, it is almost a certainty that the...
Crank no start on 2004 Ford Escape
Thanks for writing in about your 2004 Ford Escape. When the vehicle does not start, you need to check the fuel pressure and engine for spark. You should scan the computer to see if any codes are set that will...
Car gets very low gas mileage
I would do a little quick research and find out what is typical real-world MPG for others who drive your make and model. That will provide you a realistic base-line expectation that will be more accurate that Mazda or EPA...
my alarm went off when I opened door w/ key. Now it won't start. What can I do? Is there a time period it will start up again?
If you have a key fob, I would recommend locking and unlocking the doors with that to see if this resolves the issue. If you do not have a key fob, you can try to lock and unlock the doors...

Related articles

The Best Used Cars to Buy If You Live in a Windy Area
If If you live in a windy area, one of the most important things you’re going to be looking for in a used vehicle is the ability to remain stable on the road on even the most blustery days. That...
Ten Sports Cars That Double as Good Daily Drivers
The best daily driver is a car that's reliable, usable, and still fun to drive. Popular daily sports cars include the BMW M3, Subaru WRX, and VW GTI.
Top Automotive News & Stories: October 1-7
BMW i5 images leak, an ultra-lux Jeep, hydrogen-fueled Colorado ZH2, Fisker's electric future, record plug-in sales, NHTSA Road to Zero, and more.