brianbbs67

I made a mistake and refueled while running. Fuel gauge is off, ever since. I thought the owners manual had this info, but scanning through it , I can't find it. Do you guys know the trick?

Peter Ogden

I think I read somewhere that you need to use more than half the tank of fuel and then do a complete fill and it should reset itself.

DBJoe996

Never heard of this one before. You could do as described above, it might work. Or, disconnect the negative battery terminal for a short period of time, say 10 minutes, reconnect and see if that resets the fuel gauge.

dporto

I've been told by a Porsche dealer "there is no reset/re-calibration - you need a new sender"... whatever... I reset my trip odometer upon refill, and always refill around 200 miles

NuttyProfessor

I agree. This doesn't make sense at all. The fuel level system is an active measurement device. The 996 uses an age old mechanical float type system. Think about it like this - you're parked on a steep hill in San Francisco while the car is running. The fuel level reads to almost empty. You then get in the car and drive to level surface and now the gauge is reading 1/4 tank. The same principal behind sitting and pouring more fuel into the tank. It doesn't care. In my opinion, you have a malfunctioning fuel level sending unit mechanism that is located in the fuel tank. It's more than likely stuck and giving a false read. I would trying refilling it full and driving for a while and see if it unlocks itself. After a few tanks and doesn't improve, then I would recommend installing a new unit - part# 99662083302

dporto

In my case, I've got a C4 (not sure if the OP said his is a C4 or not) which has the "saddle tank" (split tank to accommodate the front diff). Because of this, the sender is only in one half of the tank...The fuel level in the other half of the tank is "interpreted" by the DME based on the info it's getting from the sender. I'm not sure I understand exactly why or how the system was designed like this. All I know, is that I've tried all of the "resets and fixes" (emptying tank, refilling tank, removing battery etc. etc. etc...asking the dealer to re-calibrate etc...). Mine still doesn't work - It reads full when full, but only goes down to slightly less than 1/4 when empty - Almost like it's calibrated for liters or something (don't know why it would be as it's a US car). Once again - whatever! If this is the worst of my problems, I'll deal with it the way I have been for the last 3.5 yrs.

fpb111

De Jeeper

Have u changed the sender or pulled it and done a test outside the tank. Its not that hard. I suspect there is something wrong with the arm or sender itself. I have had floats go bad and other issues on other cars do to age and rough roads.

rb101

I had to reset my instrument cluster on an almost empty tank on my C4 (removed the screw and disconnected the harnesses). The gauge was off on restart. I filled the tank to the max and reset the cluster once more. The gauge reset to max. Fixed.

Woodman71

Why would you refuel with the engine on? Didn't want to put your cigarette out?

Mike Murphy

Peter Ogden

Found a reference in the 996 Essential Companion (author: Adrian Streather) about an issue with the fuel level senders in pre-model year 2001, 996 Carrera 4 and GT-3 models. There is a potential problem with the fuel level system if battery power is lost for any reason and there is less than 5 US Gals of fuel in the tank. When the power is restored the fuel level reading on the instrument cluster will be incorrect or even deleted. If the fuel tank has less than 2.6 US Gals the low fuel level warning light will not function either. The only solution is to fill the tank to full to force the fuel level measuring system into an accurate operating range. Apparently the fault was eventually rectified by a software update to the instrument cluster.

dporto

"All I know, is that I've tried all of the "resets and fixes" (emptying tank, refilling tank, removing battery etc. etc. etc...asking the dealer to re-calibrate etc...). Mine still doesn't work - It reads full when full, but only goes down to slightly less than 1/4 when empty"

^^ Once again...with emphasis this time! ^^^

** I haven't pulled the sender out yet...if anything, that will be my next try...

Peter Ogden

I think you will need to bite the bullet and pull the sensor. You may find that it is simply catching up on something in the tank.

dporto