I identified a error code P0299 Underboost for a Volvo S40 2003. In spite I've deleted several times the code using my scan, the code P0299 appears again. The turbo system couldn't be activated because of that. My question is " How can I delete the code P0299 in order to activate the turbo system and have the perfect performance".

 

You know maybe something is wrong with your car. Thusly just deleting the code wont do anything. That is why it keeps coming back.

 

I've been trying to find a report about that Code error (P0299), eventhough, I couldn't find anything. Do you have any idea about the part that needsto be fixed? One of the problems is the turbo system doesn't work. Time before the turbo system activates at 2000rpm which doesn't activate now. Is it a turbo's calibration problem or is it anything else? Thank you for your support

 

The turbo does not "activate". It builds boost as the engine increases rpm as long as the wastegate actuator is functioning properly. If the wastegate actuator is disconnected or the wastegate is stuck open, then the car won't make boost. All the exhaust gases are bypassing the turbine section when the wastegate is open. The wastegate is how the turbine keeps from producing too much boost. Clear as mud?

 

OK thak´s. you have pics the part ?????

 

I found a picture from a later model S40 with the 5 cylinder engine but the wastegate actuator looks the same. To see it, lean over the engine where you can see down by the turbo heat shield, look to the right (drivers side) of the turbo and you will see a round canister thing with a rod sticking out of one end and a vacuum hose on the other end. The rod actuates the wastegate. The hose is connected to a boost source and is what makes the actuator work. Now one site I read told how you get a helper to hold the brake with the car in reverse and give it gas to bring up the RPMs and see if the actuator moves. Not the safest way to do it but effective.

 

As a suggestion check for vacuum leaks and see if any turbo hose loose.. dunno if that would help