andrewgt3

hey guys.

these two DTCs have popped up a few times now. they come back after 100 miles or so, so it's not a fluke.

P0455 Tank system - major leak
P0461 Fuel level sensor

any ideas? gas cap is tight. thanks.

ir_fuel

I also have a question. Is there a way of getting the explanation for all the fault codes? I have a durametric cable but it would be nice to buy or find some kind of manual explaining all the error codes. How do they do this @ Porsche?

andrewgt3

i used this site http://www.obd-codes.com/p0455

but, i'd still like the experience of others before bringing the car to the dealer for anything.

Larry Cable

faulty fuel level sensor...

Macster

P0455 based on my references is tank pressure sensor above limit. Possible causes: tank cap loose or missing; vent lines disconnected from EAVP canister; vent lines disconnected from tank; vent lines disconnected from purge valve; break in vent lines.

There are a bunch of checks to eliminate all of the above. Mainly they consist of verifying the cap is present and not leaking, that the vent lines are in good shape and their connections to the tank, canister and valve are ok.

I don't show anything for P0461 but it seems pretty self-explanatory to me. Does the fuel gage work? Does it register gas if you fill the tank? Does it register a drop in fuel level as you drive the car? Is its reading consist from trip to trip?

Sincerely,

Macster.

911SLOW

P0461

Diagnosis information DME
Tank fuel level
Diagnostic conditions
Normal driving
Fuel consumption, measured in the DME, after the last refuelling operation > 15 litres
No fuel level sender fault stored in the instrument cluster control unit
NOTE
In this context, please also observe the function description

Possible fault causes
Fuel level sender faulty / stuck


Function description DME
Tank fuel level (plausibility check)
The DME calculates a fuel consumption figure and compares it to the measured values from the fuel level sender.
Procedure of the function:
During initialisation of diagnosis, the tank fuel level from the instrument cluster is stored in the DME.
Afterwards, the DME uses the injected fuel quantity to calculate the fuel consumption.
When the total consumption has reached a value of 15 litres, the tank fuel level from the instrument cluster is stored again.
The values at the beginning and end of diagnosis are compared.
A fault is recognised if the difference between the two tank fuel levels deviates too much from the calculated 15 litres.
The function operates constantly and is reinitialised every 15 litres. It is interrupted and reinitialised only by a refuelling process.

911SLOW

P0455

Leakeage in fuel tank system

Diagnostic conditions
Vehicle speed = 0 km/h
Engine speed = 0 rpm
Correction factor, height > 0.73
Coolant temperature upon starting the engine may be no more than 6.8 K above ambient temperature
Coolant temperature when engine starts > 3.8 °C
Period for which the engine needs to have been running before ignition is switched off > 20 minutes
Ignition has been switched off for at least 10 seconds.
Ambient temperature 4 … 35.3 °C
Active charcoal filter load < 3 for minor leak
Fuel tank fuel level 10 … 54 litres
Battery positive voltage 11.02 ... 14.5 V
No fuel tank filling
No faults detected for ambient pressure sensor, coolant temperature sensor, vehicle speed sensor
No output stage faults detected for DMTL pump motor, DMTL switchover valves and tank vent
No fault detected for tank vent (flow)

The diagnostic conditions can also be established using the PIWIS Tester via the short test
"tank leakage test". After the test has begun, the ignition must be switched off.

NOTE
In this context, please also observe the function description.

Possible fault causes
Tank cap not closed correctly, leaking or missing
Purge air line leaking
Tank vent leaking
DMTL (Tank Leakage Diagnostics Module) leaking
Leakage in fuel tank system


Function description DME
Tank leakage test / DMTL tank
leakage diagnosis module
NOTE
The tank leakage test is performed only for USA vehicles.

Design of the tank leakage diagnosis module:
The diagnosis module consists of an electric motor with a small air pump, changeover valves and a reference nozzle.
The module is also heated to prevent formation of condensation and ice.

Function sequence:
The pump is driven by an electric motor and pumps air through the reference leak . The current consumption is measured during this operation.
The changeover valve then switches and directs the air flow into the tank. The current consumption is measured here as well. After a wait time depending on the tank level and with a
leaktight tank system, this value must be as least as high as the current consumption for the reference leak test.

The system is detected as having a leak if the current consumption for the actual leak test is lower than for the reference leak test.

Faults in the tank leakage diagnosis module can be detected by evaluation of the current consumption during startup of the pump motor and after valve switchover (e.g. pump stuck, motor turns without load, valve does not switch, etc.)

Diagnosis of the heating, motor and changeover valve takes place via the driver in the DME control unit.

andrewgt3

Hey guys.

I keep popping these DTCs:
P0455 Tank system - major leak
P0461 Fuel level sensor

I'm assuming P0455 is popping off because of the P0461. Looks like #13 in the image below.



1) Can anyone look up the part number for the fuel sender for me? I show a price of $138 at this site, but if there are better OEM parts sites please let me know.

2) Can anyone recommend a reference manual for repair like the bentley publishers CD I have for my Audi? Book or CD is fine.

Thanks!

ir_fuel

911SLOW: Where do you find that information?

andrewgt3

if anyone is following this thread - this may be the fix (fingers crossed and almost a year later):

https://rennlist.com/forums/997-gt2-...-line-fix.html