Just purchased a 2015 GLA 250 ("Edition 1" model), 84,000 miles. I am located in the Kansas City area. It came with a couple of fault codes, one of which is P0597 "The coolant thermostat has an electrical fault or open circuit."
I did a pretty extensive online search, but found no previous threads with any significant information on the forums. I found some general advice stating that German manufacturers typically build a heating element into their thermostats. The P0597 may simply mean that the electrical plug has corrosion, is not seated properly or there could be a broken wire. Or, it could be that the thermostat itself is faulty.
Looking on YouTube, it appears the thermostat resides below the intake, on the backside of the engine next to the firewall (at least that's where it's at on a CLA 250, so figured it must be the same for a GLA 250). Looks difficult to get to. I do have a 4-post lift, so I can get the vehicle up in the air.
Looking for suggestions or tips before I dive into the troubleshooting process. I will update this thread as I go, so hopefully it's helpful to others in the future.

 

Quote:

Originally Posted by kcattorney

Just purchased a 2015 GLA 250 ("Edition 1" model), 84,000 miles. I am located in the Kansas City area. It came with a couple of fault codes, one of which is P0597 "The coolant thermostat has an electrical fault or open circuit."
I did a pretty extensive online search, but found no previous threads with any significant information on the forums. I found some general advice stating that German manufacturers typically build a heating element into their thermostats. The P0597 may simply mean that the electrical plug has corrosion, is not seated properly or there could be a broken wire. Or, it could be that the thermostat itself is faulty.
Looking on YouTube, it appears the thermostat resides below the intake, on the backside of the engine next to the firewall (at least that's where it's at on a CLA 250, so figured it must be the same for a GLA 250). Looks difficult to get to. I do have a 4-post lift, so I can get the vehicle up in the air.
Looking for suggestions or tips before I dive into the troubleshooting process. I will update this thread as I go, so hopefully it's helpful to others in the future.

My 16 Gla250 has p0597 & p06da

I decided ignore both codes.

Thermostat seems maintain correct temperature, 90 ~ 105 celcious degree.
Heater doesn't matter.

P06da without cel on, can be ignored by MB technical bulletin document.

 

Hi sn202020:
Thanks for the reply. I have seen some of your other posts in other threads about the P052E code for the crankcase vent valve. I just bought both this 2015 GLA 250 and a 2017 GLC 300, and both had the P052E code and the P06DA code. Additionally, the GLA 250 had the P0597 thermostat code. I ended up purchasing two of the vent valves, part number 274 018 73 01, (cost $63 each) and splicing them into the system rather than using the Mercedes recommended part (270 090 07 00) that costs at least $638 and requires a lot more labor.

Since I was replacing the vent valve anyway, I just bought a new thermostat housing unit (you can't just buy the thermostat, apparently as it is only sold as a complete housing unit). It is part number 270 200 06 15 and I paid $62.87 for it on Amazon. It didn't make any sense to me to do all of the work to get access to the thermostat and to take a chance that just cleaning the contacts would fix the problem. It was worth springing for the new thermostat housing to save the potential of having to go back in and remove the intake manifold.

The good news is that splicing in a new vent valve worked on both the GLC 300 and the GLA 250 to resolve the P052E code, and the new thermostat fixed the P0597 code on the GLA 250. The only codes I have left on both the GLC 300 and the GLA 250 are that P06DA code, and it does not make the check engine light come on. As you correctly state, the P06DA code can simply be ignored, as recommended by Mercedes.

I made a P052E vent valve splicing video for both the GLC 300 and the GLA 250, and as soon as I've edited the video footage, I'll post them on YouTube along with a link to the videos here.

For all of owners that are dealing with either the P052E and/or P0597 codes, just know that you do NOT have to pay $2,000 to fix them. On the GLC 300, I spent about 5 hours fixing the problem because I was being very cautious and shooting videos, but I could do the job again in less than 2 hours. On the GLA 250, I spent about 4 hours combined replacing the vent valve and the thermostat. But, again, I was being cautious and taking video. Neither required any great mechanical skills nor a lift (it was all done from above). I think I could do the entire job again in about 3 hours. Parts cost for the vent valve was $73 including shipping and $63 for the thermostat housing with free shipping. In my humble opinion, even if you don't have the P0597 thermostat code, I would swap in a new thermostat in a CLA 250 while I was in there so that I didn't have to go back in to replace a thermostat later. Also, removing the thermostat makes replacing the vent valve a little easier, so the effort is about the same either way.

 

I have the same code P052E for my 2018 GLA 250, did you posted your videos on Youtube ?

 

I did post the one for the P052E code for the crankcase vent valve. I think I did another video for the thermostat code, but never posted it. I'll see if I can dig that one up. But, in the meantime, here's the code for the P052E fix (apologies that it's a little long):