Why is my fuel pressure sensor too low?

P0191 Fuel Rail Pressure Performance; could be a bad rail pressure sensor or reporting that the rail pressure is too low. If the rail pressure sensor fails, the ECM will substitute a default value.

What does check engine light on fuel rail sensor mean?

Check Engine Light comes on The fuel rail sensor, commonly referred to as the fuel pressure sensor, is an engine management component that is commonly found on diesel, and some gasoline injected vehicles. It is a part of vehicle’s fuel system and designed to monitor the fuel pressure that is present at the fuel rail.

Where is the pressure sensor on the fuel line?

I don’t remember them having a rail pressure sensor but they should have a sensor in the fuel line just in front of the tank. I believe that you are right. The guy at the auto store helped me and directed me to the Haynes manual that gave a good picture as to where its located.

What should the rail pressure sensor reading be?

If the rail pressure sensor fails, the ECM will substitute a default value. Duramax ( diagnostics) 6.6 LB7 & LLY KOEO (Key On Engine Off) rail pressure sensor should read 145 – 261 psi (1.0-1.8 Mpa) LBZ & LMM Duramax KOEO should be 0 psi. A skewed rail pressure reading will not cause a hard start.

Where is the fuel rail pressure sensor located?

As for where it is located…in the valley of the block, to the driver’s side and a little forward of the cast turbo intake pipe (which is better to remove to get to the block…and a real pain).

P0191 Fuel Rail Pressure Performance; could be a bad rail pressure sensor or reporting that the rail pressure is too low. If the rail pressure sensor fails, the ECM will substitute a default value.

What happens when a fuel rail sensor goes bad?

As the fuel pressure decreases, there is an electrical signal sent to the fuel pump to demand more fuel pressure. When a fuel rail pressure sensor begins to malfunction, there are some primary symptoms which alert you that there is something wrong. There will be difficulty starting up, making the starter engaged for a longer time than normal.

Is the fuel tank pressure sensor a 5 volt sensor?

Here are the facts about the fuel tank pressure sensor: 1) The fuel tank pressure sensor is a 0 to 5 volt sensor. 2) You should NOT see a stuck on 0 or 5 volt signal value, using a scanner or volt meter. It has to be somewhere in between. 3) If sensor’s stuck at 0 volts, then the 5 volt wire is broken.