Ive now got my second Cayenne in with a PDCC fault ..
They are intermittent .. a split second basically but amber then red warning lights until you cycle the ignition .
Both of the faults i have seen .. and bearing in mind this is new as i've never seen it before are due to a pressure problem with the rear roll bar .
First fault a couple of months back .. fault code for under and over pressure readings from the pressure sensors and intermittent .. code will always be passive if the car is not moving so codes can be cleared ..
test plan .. very complicated but it lists just about every part of the system from pump to rear roll bar .
First car . it was an educated guess to be honest .. RA pressure sensor fault .. x2 sensors in the rear valve body .. i kinda figured this was the most obvious fault .. no way i could prove it without replacing it .
Intermittent fault .. so not much i can test as the fault only happens for a split second when driving and at a certain angle whilst cornering ..
I changed the rear valve body .. ok big issue .. the pipes were all corroded .. i had to cut them all out and replace .. we are into sensible money here for a fault i cant prove until its replaced .
In this case it fixed the fault .
I now have a second car with RA pressure too low .. im leaning towards the same fix but as above its different codes and no real test plan .. wing and a prayer again .
Ok so my point .. im of the opinion that its old fluid and the sensors are blocking .. these seem to be the same as the brake sensor on the master cyl that often packs up .. debris gets in and blocks it .
I feel .. although no proof at all that a replacement PDCC reservoir which will replace most of the fluid might be the way forward .. its a hunch .. educated but a hunch none the less ..
if you have the fault then this wont help .. i tried it .
Change the reservoir which is actually a service item and change the fluid .. basically removing the reservoir will replace most of the fluid as there's no drain or bleed on these .
An FYI for you guys basically .
They are intermittent .. a split second basically but amber then red warning lights until you cycle the ignition .
Both of the faults i have seen .. and bearing in mind this is new as i've never seen it before are due to a pressure problem with the rear roll bar .
First fault a couple of months back .. fault code for under and over pressure readings from the pressure sensors and intermittent .. code will always be passive if the car is not moving so codes can be cleared ..
test plan .. very complicated but it lists just about every part of the system from pump to rear roll bar .
First car . it was an educated guess to be honest .. RA pressure sensor fault .. x2 sensors in the rear valve body .. i kinda figured this was the most obvious fault .. no way i could prove it without replacing it .
Intermittent fault .. so not much i can test as the fault only happens for a split second when driving and at a certain angle whilst cornering ..
I changed the rear valve body .. ok big issue .. the pipes were all corroded .. i had to cut them all out and replace .. we are into sensible money here for a fault i cant prove until its replaced .
In this case it fixed the fault .
I now have a second car with RA pressure too low .. im leaning towards the same fix but as above its different codes and no real test plan .. wing and a prayer again .
Ok so my point .. im of the opinion that its old fluid and the sensors are blocking .. these seem to be the same as the brake sensor on the master cyl that often packs up .. debris gets in and blocks it .
I feel .. although no proof at all that a replacement PDCC reservoir which will replace most of the fluid might be the way forward .. its a hunch .. educated but a hunch none the less ..
if you have the fault then this wont help .. i tried it .
Change the reservoir which is actually a service item and change the fluid .. basically removing the reservoir will replace most of the fluid as there's no drain or bleed on these .
An FYI for you guys basically .