luciom767

Car cranks, but won't start. Radio will not turn on either. Getting the following codes...

P0128 Coolant Thermostat
P0628 Fuel Pump A Control Circuit Low
U0109 Lost Communication with Fuel Pump Control Module

Any suggestions on where to start first? Many thanks.

alynch

Ignore the first code for the moment. The other two point to an issue with fuel delivery which would obviously cause a no-start. First, check any fuses associated with the fuel pump and the fuel pump control module. Then, check fuel pressure to see if, in fact, any fuel is being delivered to the fuel rail.

luciom767

thank you for you advice and I was out of the country and untill now I got back in my mercedes problem
I did check all the prefuse box and fuses associated with the fuel pump seem to be ok , and the fuel pressure was cero !! anyone know how can I check the pump control module ?

I did remove the rear seat and uncover the fuel pump harness electrical connector and there is no power to it not in the first click of the key neither the second position , I can see the fuel pump control module but I don't know how to check it , Can someone advise me how ?

luciom767

thank you for you advice and I was out of the country and untill now I got back in my mercedes problem
I did check all the prefuse box and fuses associated with the fuel pump seem to be ok , and the fuel pressure was cero !! anyone know how can I check the pump control module ?

I did remove the rear seat and uncover the fuel pump harness electrical connector and there is no power to it not in the first click of the key neither the second position , I can see the fuel pump control module but I don't know how to check it , Can someone advise me how ?