How to Coding Porsche 991.2 by PIWIS III

Car model and year: Porsche 991.2 with PCM4.0 without the Bose amp.


Deleted my PCM head unit. The downside is that the OEM shelf isn’t tilted enough, under hard acceleration your phones/keys/whatever you put in there will fly out…

Problem though, is that the bootup sequence of the car has a certain PCM check in it. Without the head unit, once the key is inserted and the lock barrel turned, the following “System Fault” message shows up:

Porsche 991.2 coding tool to use:

Get access to a PIWIS 3

Professional technician suggestion:

I just took a quick look, here’s how I did it when my radio was out.

From component overview list, select Gateway -> Maintenance Repairs tab -> Actual/Specified Configuration menu -> Confirm PCM is displayed with a red minus sign under “actual installation” -> Accept (F8)
Back to component overview
Select Instrument Cluster -> Manual Coding -> Next -> Uncheck PCM related options -> Accept -> *Take screen shot of old and new values at confirmation screen*
That should take care of the message in your cluster. You probably will have to clear stored faults too.

PIWIS may change some unrelated configuration parameters in your cluster, which is why I suspect you’re seeing some weird errors from your dealer’s attempts to fix this. If this happens, you need to put your PIWIS in engineering mode and correct the parameters individually using the screenshot of changed values.

If you plan on selling your PCM4, you can’t un-pair your VIN from the head unit like in previous versions. If you sell your PCM, the new owner will need to deactivate component protection at a Porsche Dealership (or anywhere with a PPN login and PIWIS III).

Finally! Solved!

Update: got it done just like–“Accepted the actual vs. specified config in the Maintenance Repairs tab and instantly dash error was gone, thanks!!

A couple discoveries along the way:
1. PADM error message is unrelated. In Actual Values there’s no current flowing to the left dynamic engine mount. A bit of searching here suggests I’m not the only one with a problematic dynamic mount. One for warranty.

2. Chalk the oil fill level message to an oversensitive sensor. Following a weekend of aggressive pulls and really running the car (must’ve burned some oil in the process) an “electronic dipstick” check cleared the dash before I even started on PIWIS.

3. While in PIWIS I was naturally curious and pulled the vehicle analysis log (“VAL”). Interesting bits: one can definitely log overrevs just by hitting the rev limiter! I logged double-digit ignition counts in Range 1 and 2. Doesn’t concern me one bit, my RS ain’t “auction material” in this or the next life. Mechanically, in Carrera Cup the same blocks regularly see 9k+ in downshifts (against an 8.8k redline and 100hr rebuild intervals) ditto 9.4k+ on the GT3R. But those looking to maintain a sterling DME should be aware!

4. Apparently there are different “authorization” levels of PIWIS. You heard it right, not all PIWIS are licensed the same. After solving my dash error at home, I showed my process to friends at the sole official dealer in Hong Kong. Really not to throw shade at their failed attempt, but to share with them what I learned. They went “whoa we don’t get these screens in our system, probably because of the different certificate levels given to us by the factory…” Both of us were floored to say the least, knowing how much the factory charges for their official PIWIS subscriptions!!

Credits to @ chris2 and @CRex!

BTW, Piwis III is really decent Porsche coding tool with a bunch of new menu and coding options when comparing to Piwis II.