Replaced water pump and switch over valve from fcp!
there was no coolant in the vacuum lines when i swapped…
don’t get what esle it can be at this point,car is due for inspection and i need this check engine fixed.
Let me know if you have experience fellas
thank you

Bump
replaced temp sensor aswell on thermostat,anyone have an idea what else it can be?
code comes on like 5 miles later when car is warmed up
zero symptoms other than check engine

I've had the same code P261F since changing water pump from from FCP euro....this post below has info about a fix....I tried it yesterday and waiting to see if it works....
https://sprinter-source.com/forums/i...s/84103/page-2
Keep me posted on your progress

Well, the P261F code came back after 264 miles and using the suggested vacuum line modification. I'll just leave the modification as is and reset the code when it pops up again until someone comes up with a fix...

It looks like in that thread the one guy that got it to work coded out the P261F code. Not sure if you did that. The other guy that was doing it never came back into the thread to comment on if it worked from what I read anyways.

Thanks for the input...I used the icarsoft scanner to remove the codes but the permanent code remained. Guess that permanent code needs to be removed...I'll check to see what I can do about that. Other threads I have read mentioned that the permanent code will be erased after 300 starts...Don't know how true that is ...I hate to go to dealership for them to remove the permanent code at the cost they charge...I'll keep y'all posted...Thanks again.

The P261F code on your E250 BlueTEC typically indicates an issue with the engine coolant pump "B" control circuit. Since you've already replaced the water pump and switchover valve, there are a few other areas you should investigate.

First, inspect the wiring and connectors related to the coolant pump. Look for any signs of damage, wear, or corrosion that might be affecting the circuit. Ensure that all connections are secure and free from debris. Faulty wiring or loose connectors can easily trigger the P261F code.

Consider the coolant temperature sensor. A malfunctioning sensor can send incorrect readings to the ECU, causing it to throw a code. Test the sensor to ensure it is operating correctly and replace it if necessary. This is a common culprit for issues related to coolant systems.

Use a good diagnostic scanner, such as the Star or YOUCANIC Scanner, can provide more detailed insights into the problem. You need a scan tool that can read manufacturer-specific codes and offer more precise information to help diagnose the issue.

Check for any software updates or recalls for your vehicle’s ECU. Sometimes, MB release updates to fix bugs or issues related to specific codes. An ECU update or reprogramming might be required to resolve the P261F code. Lets hope not because you can only do this at the dealer.