Fuel Pressure Sensor

[Viper5]

I am trying to check to see if my fuel pressure sensor is good. I unhooked the electrical cable that goes to the sensor, but I am unsure what to do now. The service manual doesn't mention anything about this. Somebody told me about checking for a 2.5v using a multimeter (which I have) but how am I supposed to check for any voltage if my battery has to be unhooked?

I have read that sometimes the harness gets worn out and that can be a cause for my CEL code P0453, but I'm not even sure which part is the harness and how to check if that is what indeed needs replacing instead of the expensive sensor.

I have provided a picture of what I'm looking at.

[Viper5]

Can somebody please help me with this? I just want to make sure it's the sensor and not something else giving me that code. I already replaced the gas cap with my older one.

[tholyoak]

Small correction, that is the tank pressure sensor, not fuel pressure sensor.
P0453 doesn't typically represent a problem with the sensor itself.
Here is the diagnosis procedure.


P0453 Above upper limit – Short circuit to B+

Diagnosis

Check wiring from pressure sensor to DME control module for short to B+.
check wiring harness for chafing and pinching damage.

[Viper5]

On the pelican parts website, the piece looks just like this and they call it the "fuel pressure sensor."

I read your diagnosis but I still don't know exactly what to do with the DME. I have a multimeter if that helps but what points am I supposed to measure and what are the values supposed to be?

I also don't understand what I'm supposed to check for with the pinching and chafing damage. When you say the wire harness, are you talking about the plug with the three wires? If so, it goes through a firewall so I'm not sure how to check it.

[Viper5]

I know where the DME is. Can somebody tell me how to check for continuity where the sockets are and the sensor is?

I can't locate wires that have the same colors because they are all jumbled together and there are hundreds of them. I'm looking for the light blue, light pink, and dark pink ones but it's practically impossible to find.

[Viper5]

new sensor fixed problem

[Viper5]

Back in June 2010 is when this issue first caused the CEL. Yesterday it popped back up again and it is reporting this dreaded P0453 once more. Argh. Considering I just replaced the darn thing 6mo ago, what could be the problem here? It seems like this part isn't ever really supposed to go bad so I can't see how in 6 mo time it did. Granted it wasn't a new install, but it lasted this long so it must had been installed correctly. I drive my boxster once or twice a week.

[Dale_K]

I don't know the answer to your problem but I bought a Durametric unit while trying to figure out a totally different problem on my car and I recall the Durametric will read the pressure value of the tank. I bring this up only because the Durametric helped me diagnose my problem and maybe it would help you too.

Basically it seems like you could have either a mechanical issue (leak in the vent system, bad sensor) or an electrical problem (chafed wire, short, etc). Since replacing the sensor fixed the problem for a while you'd think if it was the wiring the problem must be near the sensor.

If it was me I'd hook up a Durametric and watch the values while wiggling the wires. Take all this with a grain of salt because I'm not an expert by any means. And the Durametric costs $300, which might be going overboard with the technology.

[Viper5]

I already have durametric but I didn't know it reported those values. Will try and see what happens. Does it provide acceptable range too?

[Dale_K]

Originally Posted by Viper5

I already have durametric but I didn't know it reported those values. Will try and see what happens. Does it provide acceptable range too?

I'm sending you a PM.