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I put a new fuel pressure sensor in 4 days ago ran fine. Now it is coding fuel pressure sensor low pressure but I do not hear the fuel pump buzz at startup is it the fuel pump?

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  • If you're reading the code from your own scanner see if it can also read a Fuel Pressure PID and have that as a reference for when you measure your actual pressure with a Fuel Gauge
    – jxramos
    Sep 10, 2016 at 0:49

2 Answers 2

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It might be the fuel pump. Something you can replace before your fuel pump is the fuel filter. If this becomes clogged, it can give a lower pressure at the fuel rails and could trigger a low fuel pressure code to your ECM. If this doesn't work for you, then I'd check the fuel pump. The easiest way to tell is to put a fuel pressure tester at the fuel rail to see what it comes up to when you turn the key on. Most current vehicles with fuel injection has a test port which is a Schraeder valve (same basic thing as what holds air in your tires) on it (not to be confused with either of the A/C ports). I don't know exactly what the fuel pressure should be on your vehicle, but believe it should be around 43psi.

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You have changed the fuel pressure sensor, and you have a low fuel pressure reading. The fuel pressure sensor reports the fuel pressure in the system. This pressure is controlled by the fuel pressure regulator. You will need to have a fuel pressue test which at idle should be 3.7-3.9 bar. A low reading will point at the fuel pressure regulator on the fuel rail.

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  • I don't believe these Volvos use a regulator, I'd guess that pressure is maintained electronically by their Fuel Pump Control Module. It's true that as you work your way from the rail to the pump you could stumble across a bad regulator that could be interfering with the flow.
    – jxramos
    Sep 10, 2016 at 0:52

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