I own 991.1 C2S (2015) that I acquired a few years ago under CPO warranty; it was optioned with Sport Chrono and PDCC.

During the last couple years, I participated at a dozen PCA-sponsored HPDE events at different tracks. Unfortunately, most days were cut short because of recurring PDCC issues (“Suspension system fault – Adaptive driving permitted") that disengaged Sport+; I tried PDCC in Sport but the same alert was triggered. Although I was able to reset the suspension alert by restarting the engine, most of the time the same PDCC fault recurred after a few rounds into a new session.

My Porsche dealer initially diagnosed the front valve block not allowing sufficient pressure to be reached and replaced it with a modified version (991-359-075-03); the PDCC fluid was described as dark, although it was only 3 years old. After another PDCC fault at a following HPDE event, a different Porsche dealer updated the PDCC software. Subsequently, multiple repair attempts under CPO warranty for recurring PDCC faults remained unsuccessful, even after replacement of: PDCC hydraulic pump and hydraulic fluid, both front actuators, and PDCC control unit. In all instances the PDCC fault was attributed to insufficient front PDCC pressure buildup; however, a root cause for it was never identified.

I finally asked my dealer to reach out to PCNA, who stated that "the fault is most likely due to the specific driving conditions and style on track...and recommends either changing driving style or wait for fault to clear before proceeding." For the record, the PDCC failures were neither related to my driving style nor track configuration as senior PCA instructors also experienced repeatedly the same failures on different tracks. It was particularly concerning as disengagement of Sport+ with each PDCC fault appeared to unsettle the car. Since the PDCC faults only occurred on the track but could not be replicated in the Porsche shop, PCNA did not authorize any further repairs under CPO warranty.

I am understandably very disappointed in PCNA and frustrated to own a 911 that has repeat PDCC failures at HPDE events. I would greatly appreciate any insight for possible repair solutions.

Thank you!

 

There's another member here who has similar issues on certain uneven terrain at track days. Hopefully he'll chime in, I can't remember if his issue was ever resolved.

 

Sorry to see this. I have a lot of track days on my 991.2 GTS with PDCC and not a single hiccup with the system.

 

Thanks for your assistance, "asellus"!
I recall reading another member's thread on a similar suspension issue. I will try to get in contact with him/her for further input.
I have attached a pic of the yellow suspension alert. Although I can’t consistently replicate the fault, it typically occurs in close right-left turn combinations after several rounds in the later sessions of the day.


PASM/PDCC fault

 

If you fix it for 1200 that's cheap, might be worth a shot.

 

Thanks for your suggestion to consider installation of a DSC box!
I will reach out to DSC Sport if their V3 controller is a possible solution to fix my suspension faults.
Will provide updates...

 

Unfortunately the DSC controller won't resolve a PDCC issue. PDCC is a separate system that has its own controller to control the electronic sway bars. DSC controller controls the electronic dampers. The only connection between the electronic sway bars and the electronic dampers that is they share the same "Active Suspension Fault" message on the instrument cluster when a fault occurs. And on some cars they share the same button to activate Sport mode.

I have experienced this driving someone's car before, when PDCC had a an issue it felt like as if the sway bars were removed from the car.

 

convert to static mounts?

 

I had this problem with my GT3 RS on Daytona International Speedway. It only occurs if the car is doing something that the computer doesn't understand (like driving 130+mph on a 31 degree bank at Daytona). Yes, PDK sport doesn't work when this fault occurs, and keeps the car in a sort of limp mode. The only work-around that I've found is that I have to drive in manual mode at Daytona. When I drive in manual mode, the fault doesn't occur, and I can stay in Sport + mode, and drive the car the way it's meant to be driven.

edit: or perhaps it did keep me out of sport + mode, but when you're in manual shift mode, sport + doesn't come into play, as I could still redline the revs in manual mode. You just have to be more attuned to the engine sounds, so that you shift before you stall at the redline rev-limiter.

 

Thanks for your message!
Just for clarification, my car has PASM and PDCC (s. attached pic). I will definitely try manual mode next time I track my car in Sport+ with Sport Chassis selected by PASM / PDCC.
My understanding is that the GT3 RS does not come with PDCC - correct? Does your GT3 RS display the PDCC logo on the PASM button?

 

The GT3 RS only has PASM, not PDCC.

Also, if I recollect, PSM (TC+ESC) may also have been disabled when I got the suspension fault, or I may have simply turned them off.

 

Thanks for your input, Tom!

As mentioned, I can’t consistently replicate the PDCC faults but I have observed the following characteristics on always the same 3 out of 4 tracks:

• repeatedly in close and tight right-left turn combinations, particularly when braking before the 1st turn (never had an issue during AutoCross)
• almost always after several rounds in the later sessions of the day
• typically in the hot summer months (vs cooler days in spring)
• usually when driving solo and rarely with instructor on passenger seat

In your expert opinion, what do you think is the root cause for the PDCC faults?

1. Mechanical or sensor issue in the PDCC system that has not been identified and fixed yet (although almost all part of if have been replaced)
2. Engineering design flaw by Porsche
3. Driving style and/or track configuration as claimed by PCNA

I remain very frustrated to own a 911 that is designed and promoted by Porsche to be driven on a track but has repeat suspension failures. I am not sure how to move forward after additional diagnostic and repair attempts by my Porsche dealer were declined by PCNA (CPO expired). Any further guidance on how to address the recurring PDCC faults is greatly appreciated.

 

Your car has both PASM and PDCC. If you have both PDCC and PASM, then are you sure that the problem is PDCC and not PASM?

 

TRACKING, I also have a PDCC car with DSC, but yet to have PDCC faults, fortunately mine has been flawless on and off track for 92k miles. My local tracks are Thunder Hill, Infineon and Laguna Seca.

As Tom mentioned the PDCC and PASM are activated with the same button your car says PDCC, the older cars the button is labeled as PASM. I am curious if you might have a fault somewhere in your PASM system. Like a loose connector on one of the shocks or even possibly one of the shocks going bad and causing a short in the system?

NOTE I also got a suspension error when my clock spring started to die. Somehow the steering and the active suspension systems talk to each other.

Good luck in your hunt here and keep us updated.

 

Thank you both for your input!

I actually had and still have the same question you posted: Is there a problem with PASM besides or in addition to PDCC - not according to 3 different Porsche technicians who serviced the car.

To recap, I participated at a dozen HDPE events (4 different tracks) during the last couple years. I never had an issue at 2 Road America events; I experienced approximately 20 suspension faults at 7 of the other 10 events, all at one of the following 3 tracks: often at Autobahn South (never on North) and Blackhawk, and occasionally at Gingerman.

Each time after the car was interrogated at a Porsche shop, the technician attributed the suspension fault to a PDCC issue secondary to insufficient pressure built-up in the front. After each of the several repair attempts (PDCC front valve block, software update, PDCC hydraulic pump and fluid, both front actuators, and PDCC control unit), the Porsche technician could never replicate a suspension fault on the test bench or during sporty test driving on curvy street roads.

Given the above info, how likely is it that different technicians (one had particular expertise in suspension) would miss diagnosing an issue with PASM (connector, sensor, etc) or a bad shock? Any advise on next steps?