2018 C300 M264 circulation coolant pump fault

[Zepspeed]

Hi. I am new here. Got a 2018 C300 petrol engine M264. It gives 3 fault codes:
P0A0500 actuation of circulation pump for low temperature has an open circuit.
P00B700 coolant flow too low.
P0C7300 Circulation pump 1 for low temperature has a malfunction.

I changed pump and updated software but it is still same. Car is running fine and coolant temps are normal under load. Any suggestions are very welcome.

 

[AMGeed]

Do the fault codes reappear , assuming you cleared them after the repair?

 

[Zepspeed]

Do the fault codes reappear , assuming you cleared them after the repair?

Hi. Yes the faults appear after a short drive

 

[Jobsworth]

Are you sure you replaced the correct pump? There are more than one on some of these cars. You can identify them if unsure by leaving unplugged and running the car, see what fault code comes up.

 

[Zepspeed]

I have not looked at the engine water pump. It could be the type with actuator and an electric switch.

 

[Ashtray]

What was the issue eventually and what was done to fix it ?

I have the exact same issue on my Mercedes Benz m264 c200 EQ. Those 3 exact codes pop up after a short trip.

Replaced the electric coolant pumps on either side of the wheel well underneath headlights, thermostat, bled the coolant, pressure tested the system etc.

 

[Rakesh]

Hi. I am new here. Got a 2018 C300 petrol engine M264. It gives 3 fault codes:
P0A0500 actuation of circulation pump for low temperature has an open circuit.
P00B700 coolant flow too low.
P0C7300 Circulation pump 1 for low temperature has a malfunction.

I changed pump and updated software but it is still same. Car is running fine and coolant temps are normal under load. Any suggestions are very welcome.

Hi , did u get a working solution for the P0A0500 and PooB700 error codes

 

[Mrmoo91]

Hello i have same error code, do you solved it?

 

[mioba]

Sadly one of those threads by one post wonders. It would be nice if ppl can post the solutions to their own questions atleast.

 

[Rakesh]

Hi , did u get a working solution for the P0A0500 and PooB700 error codes

Good evening... I was sucessful in removing the error codes ... The 2019 m264 eq boost, actually has three (3) pumps two (2) located under the head lights (right had drive models.. right additional coolant pump is for the intercooler...the left is for the 48v battery, independent of the the third additional cooling pump wich is locacated under the intake manifold which is for the starter/alternator and the transmission cooler however integrated into the engine cooling system)....the radiator fluid was drained...pump was replaced (as the three pin plug didn't have any open circuit) the system was vacuum filled and the bleed procedure (using scan tool) was executed. Additionally all four pumps ( three (3) additional water pumps and the main pump) were activated to further purge the system of air, after which I drove for approx 1hour an no errors came back.
Bench testing of the brushless motor for the pump reveled that the circuit within the motor was faulty.
Hope this helps ...

 

[romekc]

Hi

did someone solved the problem?
I have changed 3 pumps without success.

 

[Mani0001]

Hi, I am having the exact same issue. Did anybody resolve this? I am getting 2 fault codes- P00B7-00 The coolant flow is too low and P0A05-00 The actuation of the circulation pump for the low temperature circuit has an open circuit. The vehicle is a Mercedes C200 2017 1.5 petrol EQ boost. I have replaced all three pumps (2 behind the headlights and 1 under the inlet manifold) but still the same faults keep appearing. Any help would be appreciated as I have run out of ideas. Thank You

 

[Oleks1992]

Hi, I am having the exact same issue. Did anybody resolve this? I am getting 2 fault codes- P00B7-00 The coolant flow is too low and P0A05-00 The actuation of the circulation pump for the low temperature circuit has an open circuit. The vehicle is a Mercedes C200 2017 1.5 petrol EQ boost. I have replaced all three pumps (2 behind the headlights and 1 under the inlet manifold) but still the same faults keep appearing. Any help would be appreciated as I have run out of ideas. Thank You

Have you vacuum filled the cooling system? As low temperature circuit is impossible to bleed the usual way

 

[Mani0001]

Hi, thanks for the reply. Yes I have bled it using vacuum purge and refill kit.

 

[Oleks1992]

Hi, thanks for the reply. Yes I have bled it using vacuum purge and refill kit.

There is TSB for this issue. Try and investigate it further

 

[Mani0001]

Thank You will take a look at this.

 

[Nareshhk]

Thank You will take a look at this.

Hi any solution for this I had same problems when change the coolant in electric motor section any idea to solve if

 

[Mani0001]

Hi, yes managed to get it solved. It had to be bled using mercedes dealer diagnostic machine.

 

[Nareshhk]

Hi, yes managed to get it solved. It had to be bled using mercedes dealer diagnostic machine.

You bled machine right I want to buy1 lead thanks for saving my life sir good wishes

 

[Oleks1992]

You bled machine right I want to buy1 lead thanks for saving my life sir good wishes

Yeah like I was saying before about bleeding procedure. Glad you got it sorted though!