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just trying to help my brother as he got CEL on his 2014 GLK 250 BT. Was diagnosed from private Mercedes mechanic with a P261F code. I’ve searched and there’s little to no info on this code. The one poster posted but his link was for P2601 code (auxiliary coolant pump?) vs P261F.
Mercedes mechanic said code was likely related to tranny, and since car never had tranny fluid replaced, and was at 75k miles, he flushed and replaced. CEL came back on after 2500 miles.
Anyone have similar fault, and/or suggestions on what this fault code is pointing to? My mechanic’s a good guy, and used to work for Mercedes a while back, with many years of experience. But, I’m also contemplating on taking the car to another shop(Toronto area) if his diagnosis is deemed to be unclear or we’ll off track..
Marek, I’m going to see the mechanic tomorrow, with my brother. I thought the code came from MB scanner, but doesn’t look like it is? It’s either that, or my brother didn’t get all the codes..
Does the 2014 GLK 250 BT have an auxiliary coolant pump? Or is it just water pump on this model? I wasn’t able to find the part for auxiliary coolant pump.
So I went by the shop and the mechanic was using a basic scanner, and the same code P261F code came back up. He didn’t have the time today, and will diagnose and check with his MB scanner next week..
My brother has been driving for 4 days with the CEL, and no change in driving or operating temperature. Should be ok to drive around for another week? Or do you think the car should not be driven until it’s properly diagnosed?
So I went by the shop and the mechanic was using a basic scanner, and the same code P261F code came back up. He didn’t have the time today, and will diagnose and check with his MB scanner next week..
My brother has been driving for 4 days with the CEL, and no change in driving or operating temperature. Should be ok to drive around for another week? Or do you think the car should not be driven until it’s properly diagnosed?
Keep in mind that CELs are generally related to emissions stuff. In other words, the engine is rarely, if ever, in critical danger. If it was, it would fall in «limp mode» to protect itself.
Just a quick update, the circulation coolant pump had to be replaced (water pump?) Mechanic also checked relay, and it was operating within spec. So far so good after a few days.
Looks like my water pump is on its last leg which most likely borked change-over valve too. I can see coolant residue in the vacuum connector and some coolant on and around change-over valve ... Dammit...truck has only 76000 kms ...
Absolutely no change in power output or heating/cooling though. GLK drives like normal except the engine light.
Some pictures of initial diagnostics in the garage
The plan is to replace water pump (coolant as well) first, and if I keep getting P261F code then replace switchover valve and wastegate control pressure transducer, Y77/7. Not sure about the rollers, tensioner and V-belt, I have to check when those are due. I am at 76000K still, for all my other cars I haven't replaced rollers, belts and a pump well into 110K.
So far I capped water pump and change-over valve, where it's connecting to water pump and code is not coming back. I keep an eye on the coolant and I don't see level dropping. I think it only takes a few drops to trigger the sensor since vacuum lines have such a small diameter. 6046463739637638
GLK350 2010 Sold C63 AMG 2012 Sedan Sold GLK250 2013
Hey Guys
I considered starting a new thread but thought maybe all these questions should be under the same post. I have 2013 GLK250 and it has 170K km (105K miles). When the temp dipped a few days ago (-2 degrees C) my check engine light came on and i got that same above error code. I reset it and it came back in 24 hours. I took things apart yesterday to see if there are any leaks as described above. Everything was bone dry. Today outside temp has been (2 degrees C) and the light went out on its own. Now i don't know if i should replace the pump (or accessories) or not. Do any of you guys have any thoughts on this. Should i just wait and keep an eye on it. Is there a shelf life for these pumps. I know my mileage is high and things tend to go.
I'm pretty sure the thermostat (being electric) is most likely fine. You'd know if it wasn't (check engine light and code). I would reuse unless you have reason to believe it's unreliable. A lot of times, replacements just don't do the same good job.
I would definitely do the belt, all rollers and the tensioner for peace of mind. In fact, I plan on doing this regardless, at 120K.
2014 E250 BlueTec RWD, 2015 GLK250 (Sold), 2025 GLE450E (On Order 4 May)
P261F code
While I have both an E250 and GLK250, My E had a P261F code pop up (120k miles). I took it to the Dealer (still under the extended warranty that I purchased when new). Service Adviser can back an hour later and show me a list of parts, of which that needed to be ordered ,MB provided a Lyft ride home and back, once the E is repaired. I will provide the parts #'s used once I get the car back. SA also suggested that the thermostat be replace and I asked if that was covered, he came back stated it would be. I asked if the vacuum lines and system are cleared and check since the error code indicated that coolant might of been introduced in the vacuum system by reading and following links in this post, he stated that is the procedure to follow per the service department on this error and replacement of parts. More to follow.
I have started to get this code myself. I tested the water pump by applying vaccuum and it was fine. So I guess I should try replacing the changeover valve?
Looks like my water pump is on its last leg which most likely borked change-over valve too. I can see coolant residue in the vacuum connector and some coolant on and around change-over valve ... Dammit...truck has only 76000 kms ...
Absolutely no change in power output or heating/cooling though. GLK drives like normal except the engine light.
Some pictures of initial diagnostics in the garage
Hey thanks for posting. Same problem on mine.
I have to replace that change over valve (last picture on your post). Can you tell me where its located exactly?? Is it possible to DIY?? Cheers.
Hey thanks for posting. Same problem on mine.
I have to replace that change over valve (last picture on your post). Can you tell me where its located exactly?? Is it possible to DIY?? Cheers.
Front of the engine, right above water pump. First picture of my post shows it. Here is another picture of a switchover valve:
Very DIY’ble Take off intake, top engine cover, front engine cover, disconnect hoses/plugs leading to it, remove it from the bracket.
Thanks dzl_benz for the images and KTM530 for the ohms.
I replaced the thermostat and the change over valve tonight and reset the CEL (which was reporting P261F(00)).
The change over valve I took off measured 43ohms so I'm not sure I solved anything
Will see if it comes back after a drive tomorrow. If it does I'll need go to the dealer for a new water pump (and will do engine belt while there). They want $1800 just to change the water pump...
Sad update: Had the water pump replaced at the dealer ($1300 !!!), and also replaced the change over valve and thermostat. Everything was fine for a week and now the CEL is on again, same code P261F
Any suggestions for other parts that could be involved greatly appreciated
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which most likely borked change-over valve too. I can see coolant residue in the vacuum connector and some coolant on and around change-over valve ... Dammit...truck has only 76000 kms ...
,MB provided a Lyft ride home and back, once the E is repaired. I will provide the parts #'s used once I get the car back. SA also suggested that the thermostat be replace and I asked if that was covered, he came back stated it would be. I asked if the vacuum lines and system are cleared and check since the error code indicated that coolant might of been introduced in the vacuum system by reading and following links in this post, he stated that is the procedure to follow per the service department on this error and replacement of parts. More to follow.
Take off intake, top engine cover, front engine cover, disconnect hoses/plugs leading to it, remove it from the bracket.
