The engin check on my XC70 came up. the error code was P0236. I replaced the Turbo Control Valve (TCV) or Boost Control Valve- same thing and I got P0236 and P037. I replaced the 3 hoses the conected to it. One hose (red) goes to the lower section of the turbo (only reached from under the car, one hose goes to the waste-gate (I believe yellow) at the top of the turbo (much easier to reach) and then the (I believe blue) goes to the under side of the intake hose, past the air filter housing.
I disconnected the battery for 20 minuts areconnected. turend the car on, the same reeors, P0236 and P0237.

The rectangular piece on top is a connector for an electrical plug:

Help please

 

The problem solved by replacing the Boost Pressure Censor that Volvo calls it MAP sensor. It is located on the hose coming from the top of the radiator, on the plastic part of it. Volvo P/N 9125462.

 

i am fighting the same problem on my 2002 s80, i have concluded that that the "boost pressure sensor" is the culpret, will change that out when i get it on order, glad to here it fixed your issue.

 

i just installed my new MAP sensor on my s8, and wow did it make a difference, man you mash the gas and watch out lmao.
by the way it did clear my code

 

how do you remove and replace that sensor?

 

If its the map sensor,its located in the hose that feeds the ETM under the intake. The Boost pressure sensor is located in the drivers side of the intercooler.