P261F CEL code on 2014 GLK 250 BT
Member
Joined: May 2015
Posts: 96
Likes: 25
From: Calgary, AB, Canada
2015 GLK 250 BlueTec with AMG Sport package.
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
Any suggestions for other parts that could be involved greatly appreciated
Junior Member
Joined: Apr 2020
Posts: 23
Likes: 2
GLK250
Did anyone with P261F figure out a definitive solution? CEL has been on for me after the shop replaced my water pump (2014 GLK250). I pulled as many vacuum lines as I could and didn’t find any dried coolant. Vacuum reservoir connections all look good. Close to taking it to the dealer at this point.
Junior Member
Joined: Dec 2016
Posts: 36
Likes: 14
From: NY
GLK250
You can read the thread above and see what I did to solve my CEL. Changing all the major components did not help in my case.
I was about to start replacing vacuum lines when without any further intervention the CEL stopped coming on, no more codes!
The only thing I can add was that the timing was at the end of winter, so warmer temperatures may have played a part.
BTW the car throughout ran fine, mantained correct temperature. I must have driven it with the CEL on for 6 months and only bothered to get it fixed as I needed a State Inspection. Now 6 months later with nothing else changed still no CEL or codes. Go figure!
I was about to start replacing vacuum lines when without any further intervention the CEL stopped coming on, no more codes!
The only thing I can add was that the timing was at the end of winter, so warmer temperatures may have played a part.
BTW the car throughout ran fine, mantained correct temperature. I must have driven it with the CEL on for 6 months and only bothered to get it fixed as I needed a State Inspection. Now 6 months later with nothing else changed still no CEL or codes. Go figure!
Junior Member
Joined: Apr 2020
Posts: 23
Likes: 2
GLK250
Appreciate the follow up with your experience. My local shop told me it’s likely a permanent code that requires 300 key cycles to clear. That seems to line up with your 6 months until the CEL cleared. I’ll let it ride for now… might need a smog towards the end of the year.
Member
Joined: May 2015
Posts: 96
Likes: 25
From: Calgary, AB, Canada
2015 GLK 250 BlueTec with AMG Sport package.
Newbie
Joined: Sep 2016
Posts: 10
Likes: 1
From: UPSTATE NY
2015 GLK250
GLK250
The water pump is the AUX pump in GLK250. Found the AUX is not installed in my 2015 GLK250.
Vacuum solenoid actuated water pump is on mine and I guess it act as AUX pump function in starting.
Vacuum solenoid actuated water pump is on mine and I guess it act as AUX pump function in starting.
Newbie
Joined: Sep 2016
Posts: 10
Likes: 1
From: UPSTATE NY
2015 GLK250
After all I replaced water pump from FCP and still had the issue. Checked all Vacuum lines good. No fix. Took it to MB dealer and their Diag" was water pump and switch over valve. Since I had both replaced and the water pump was after market part. So, replaced the water pump with housing from MB parts and that fix the issue.
Some reason the water pump it self (not OEM) didn't fix the issue.
Some reason the water pump it self (not OEM) didn't fix the issue.
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Member
Joined: May 2015
Posts: 96
Likes: 25
From: Calgary, AB, Canada
2015 GLK 250 BlueTec with AMG Sport package.
Hmm, might be the type of water pump FCP offered. I noticed that on IDparts site there are non-variable pumps available (https://www.idparts.com/water-pump-n...0-p-14446.html ) and (https://www.idparts.com/water-pump-n...5-p-14654.html). Part numbers do differ but visually it looks the same (still has a connector for the vacuum tube)
Junior Member
Joined: Apr 2020
Posts: 23
Likes: 2
GLK250
Hi all, finally resolved this issue for my 2014 GLK250 (by force since I needed to pass a SMOG check). The aftermarket pump installed previously was indeed the culprit; I never observed any coolant fouling of the vacuum lines. Here is the correct Genuine Mercedes part number that worked for me: 651-200-78-01-80 (ordered from mboemparts_com). Apparently a lot of part sites will give a different version of the pump when you enter your vehicle info, so be careful-- a rep actually reached out and corrected my original attempted purchase. Please note it came with the incorrect plastic flange attached (only one outlet), but I was easily able to transfer over the old one with a tamper torx T30. The water pump change itself wasn't very difficult, although tedious to remove the various brackets and hoses. I left the fan and radiator in place during the process.
This mechanic gives a good description and diagnostic approach for the issue:
Slight differences in the install since it's a Sprinter van, but generally the same.
Such a relief to finally see the CEL gone! Good luck out there.
This mechanic gives a good description and diagnostic approach for the issue:
Such a relief to finally see the CEL gone! Good luck out there.
Junior Member
Joined: Nov 2024
Posts: 26
Likes: 2
2015 GLK 250
After all I replaced water pump from FCP and still had the issue. Checked all Vacuum lines good. No fix. Took it to MB dealer and their Diag" was water pump and switch over valve. Since I had both replaced and the water pump was after market part. So, replaced the water pump with housing from MB parts and that fix the issue.
Some reason the water pump it self (not OEM) didn't fix the issue.
Some reason the water pump it self (not OEM) didn't fix the issue.
