09 Cayenne 5504 Fault Code

[Davet18]

I just did a thermostat change out on my 09 Cayenne s and I am getting an error code 5504 no signal/communications? I cannot find this code anywhere?

Anyone have any ideas?

[Loren]

If your sure the fault code is correct the "55" at the start would signify a lid problem - like hood open.

[Davet18]

Yes it was 5504 but it showed up under the engine section on Durametrics. I reset it and will see. If it is a lid/trunk or door problem I am not worried about it. I was concerned because of the thermostat changeout.

As always thanks for your help. :cheers:

[Davet18]

The check engine light came on again and durametrics showed fault code 5504 again, no signal/communications. Module identification is "Siemens Digital Motor Electronics SDI4". I drove the Cayenne for a week after I reset the fault code before the light came on. Can you provide any guidance where the hood latch switch is located? Maybe something got loose or moved when I leaned in working on the thermostat.

[Davet18]

FYI, I talked to Durametrics and the software is reversing the code. It should be a code 0455: Evaporative emission system leak detected. They will correct the software on the next update.

[Loren]

P0455 Evaporative Emission System Leak Detected (large leak)

Possible cause of fault

- Tank cap not tightened correctly, faulty or missing

- Mechanical fault in EVAP canister purge valve (does not close fully)

- Leakage diagnosis pump leaking internally (membrane) or externally

- Mechanical fault in EVAP canister shutoff valve (does not close fully when power is supplied)

- EVAP canister shutoff valve connections leaking

- Tank system (including pipes) leaking

[Davet18]

I traced all of the vacuum hoses that I removed/moved during the thermostat replacement and found one in the back that was cracked. I replaced it tonight.

Thanks