2003 Carrera 2 fuel gage problem

[JW101]

Hi guys, new member and newbie Porsche owner.

I have just noticed that the fuel gage doesn't read "full" after I filled up with gas.

I have read posts on the web that range from saying the dealer must "calibrate" the gage after draining the tank, to others that say you can reset the whole thing by disconnecting the battery overnight.

Does anyone know if disconnecting the battery will fix this, and more importantly, will disconnecting the battery cause any other problems that I'll need to resolve?

Also, I decided to look at the cabin filter, and it looks like there should be a cover over the top of the element that mates to a plastic latch. My car has the outer cover that needs a Torx bit to remove, but the cover over the element is not there; is this normal?

Thanks for any help

[logray]

Welcome to rt.org from a fellow nor cal neighbor.

Sorry, disconnecting will not likely fix this problem on a c2, spend some time with search here there are many possibilities for a low fuel indication on fill up.

I don't recall there being a cover on top of the cabing filter (under the cowling that is secured by a torx fastener).

[JFP in PA]

Calibration of the fuel system is a time consuming process and requires access to a PST II/PIWIS unit to accomplish. The tank has to be totally drained, then refilled with a specific amount of fuel for the process. Disconnecting the battery is not going to do it.................

[logray]

+1 to above post.

I've personally encountered a situation where my fuel level sender is shot, even after following the factory procedure per JFP's post with a PST2 I received an error that my level sender was beyond limits and could no longer be calibrated.

There are other possibilites as well though, from misrouted hoses in the fuel tank (TSB was issued, mostly for earlier model years IIRC), to malfunctioning valves and flaps, and perhaps even a faulty instrument cluster.

[Reborn996]

I recently ran into this issue on my 2001 C2... payed my local dealer to install a new fuel sending unit and have it calibrated, only to find out the newer PST2 units are not working with some of the modules in older cars including mine! They were not able to calibrate it. If anyone knows of a place in the bay area that can do this please post it! :)

[RFM]

Only C4 - Turbo have need to be calibrated cause their specific fuel tank design (saddlebag) and fuel sender/pump unit possition inside the tank. C2 - Boxster and other rear wheel drive Porsche's have a more classic fuel tank design with the fuel sender/pump unit on the bottom of the tank, therefor a calibration is unnecessary.