new problems: PSM failure workshop, airsuspension, and probably transmission
 

under one hard acceleration, the "PSM failure workshop" showed up. it happened before and it dissapeared in a bit. but this time it stays and the PSM switch does not work (last time it happened, I could switch PSM on or off although the failure msg showed up at same time)

and then the "air suspension workshop" msg showed up. and then it was gone. just like before.

and then the check engine light showed up. and then gone.

and then for a couple of times the gear selection on the dash display failed to show which gear i was in. rather all lights up. i checked the manual it says it is transmission problem. it came and went away. transmission feels normal. a little bumpy from gear 2 to 3 but normal to me.

everything works just fine. except this msg on the dash. pretty annoying.

i did my research. Now i suspect it is the battery. previous owner told me he replaced one of them and suggest I replace the other. also I got conflict answers on which battery starts the car and which powers the accessories.
any suggestions?? thanks a lot!hilarious

psm failure / air suspension
 

Hi zzzx,

I am having the same problems with my 04 Cayenne S.
Were you able to fix the problem? What were the findings.

Any feedback would be a great help.

Thank you.

cpa

Well I reset the Psm error and it never came back. I also serviced my secondary battery since some posts suggest that a faulty battery could cause these and my mechanic friend checked the battery with his fancy $1300 tools and it seems the battery was good after that. The camshaft p0016 light still comes and goes. And same thing with the air suspension work shop light. But i noticed sometimes the pump works longer to lift the truck. That might be a reason because computer will think it takes too long. Most of time the air sus works no problem at all
I keep monitoring the errors and might replace the camshaft or crankshaft sensors or both later. Not sure if I have to take the intake mani off again.
Hope that helps
Let me know what u find. Thx

What year is your Cayenne?

I know that the 2003-2004 had a bad piston ring in the air compressor for the air suspension. VW recalled all the Tour-eggs for this issue. Porsche did not, even though the compressor is the same.

There is a piston ring update kit that you can buy from the VW dealer. It is a VERY simple repair. Just take the plastic cover off the bottom of the passenger side rocker panel. This will expose the compressor. Lower it down, take out the 2 cyl head bolts and slide it off. Swap the piston ring, put on new o-ring and reassemble everything.

Also, any amount of the alignment being off could set off a PSM failure when you go over any sort of rough road at speed, or around certain corners.

Thanks alot for the information. Mine is a 2004 CTT with 100k miles. With all these problems I still think it is THE BEST suv out there.

My warning light does not come up that often and the height adjustment seems to be normal. Still, I ordered the repair kit from vw dealer for $199 including tax. Does not include the elbow in the following link
http://www.renntech.org/forums//tuto...004-cayenne-s/
They told me I could have it on Friday. I will keep you guys posted after I change it.
I did notice when I lift the truck to a higher setting, the air compressor on the right side makes quite a bit of noise. And when I drive on uneven surfaces the right side makes some clicking noise although not that loud. I guess that is the compressor trying to catch up.

Regarding the Psm light,like I said it never come back. But since I just put on new set of tires I am going to get it aligned on Friday morning. I noticed before the new tires the truck pulls to right. And inside shoulders on all 4 old ones wear more. On the new ones the truck drives straight but I still want to set it up properly.
2 local dealers quote me $325+tax and $395+tax for the alignment. And the expensive one refused to match the price. At the same time they told me it is 1 hour job. How nice! So i am sending it to a reputable shop specialized in vw
Audi Porsche

Now the camshaft msg. It comes and goes more often. And the dashboard display does not show it in the system information/warning section. But obd2 shows p0016 error. And the CEL light is there. Car drives normal. Any suggestions? Do I have to take off the intake for the camshaft sensor? And where is the crankshaft sensor? Or do I really have to change them.

Thanks guyshilarious

zzzx,

Thanks for your feedback. I tried to reset the psm failure and it came back after a few miles of running. This thing never came though until I recently changed my set of rims from 18s to oem 20"s. I still did not have them aligned though. I don't know if it causes the psm failure light to turn on.

I think however, the air suspension sensor need to be replaced. It does have the same behavior as you described with yours.. There are noises sometimes when it hits the bumps. Not all the time though. Mine is in the front right area.

Hope to resolve this soon.

cpa

Cole,

My PSM failure workshop light has been lighting recently. You mentioned any alignment that may be off can cause this. I recently changed my 18"s rims to oem 20"s and have yet to align them. Can this be a possible cause for the PSM failure light to turn on?

By the way, my air suspension failure workshop has been lighting before I changed the rims.

Anyway, were you referring to air suspension alignment, or wheel alignment that may cause the psm failure light to turn on?

Thanks so much. Any feedback would be a great help.

cpa

CPA
How do u know it is the sensor problem?did u get it checked at the dealer? Mine is at passenger side on the front as well. I will start with the pump rebuild kit since from my experience in construction equipment, usually the piston ring and o ring are the first things to look at for pneumatic tools.
From 18 to 20 does change some parameters but I doubt it will trigger the Psm failure. People change to 18 snow tires from 20 summer ones all the time Again I am not sure.
Good luck with the troubleshooting. I will post some updates after the alignment and pump rebuild this Friday.

Cpa can u change back to the 18 s and reset the Psm and see if it works?this way u know the rim size does matters.
I also searched on what exactly happens with air suspension alignment but it seems the answers are all over the place. And even one local dealer told me 3 hours job while the other said it is 1 hour. And since the height is adjustable ,it seems to me that it is just impossible to get perfect alignment for all height settings. I suppose we can just get a good one on one of the heights and compromised on the rest.

zzzx,

Yes, i had it checked with a local shop that has a computer to diagnose the Cayenne.
This was the findings:
1769 Vehicle Level Sensor front right

regarding the PSM, I also get a lot of different opinions. I found this recently also that led me to believe that the changing of my set of wheels caused this to light.:
http://forums.rennlist.com/rennforum...-of-power.html

i'll keep you posted.

Thanks.

cpa

I guess in threory it could be both.

I was referring to the actual wheel alightment. The PSM monitors individual wheel speed, yaw sensor and steering angle. Having even one wheel slightly off will screw with this calculation.

I suppose that if you had a slight problem with one set of tires it could be amplified by a different set. Did you change the wheel setting in the computer? If not this would add to the problem.

On the other hand the wheel alighnment changes with ride height. So if one or more wheels is not getting up to the right height, I suppose it could in threory toss off the alignment enough to cause the above issue.

Cole,

Thanks for your input.
I will look into this. I did not change the wheel setting in the computer. I will also look into the wheel alignment.

Thanks.

cpa

zzzx,

I went through your first post again and it is exactly what is happening to my Cayenne.
Air Suspension Workshop, PSM Failure Workshop, Check Engine, and even then a couple of times also, the dash did not display the gear I was in.

Before I had all these problems, it all started with the Air Suspension Workshop lighting for a couple of weeks but would disappear, but about a week ago, it never got lost despite a reset. (level sensor front right detected)

After I changed to 20"s from 18"s, a few days after, everything started to show up... the PSM failure, check engine, ... (i am not sure if it had anything to do with my changing of rim size) - might try going back 18s and observe as you suggested.

Right now, I am thinking 3 possibilities:
1. The Level Sensor (front right) needs to be replaced based on the diagnose from dealer. I am wondering if the air suspension failure is causing the PSM failure light and check engine to turn on as an effect of the misalignment. (a possibility as per our local mechanic and as mentioned by Cole too).
2. Battery - I changed my battery a year ago with an aftermarket one, and instead of 110ah, it was replaced with a 100ah by my local mechanic. It did work fine for a year. I am not sure if the 10ah difference will matter though.
3. Wheel Alignment needed. I still didn't do this when I switched from 18s to 20s. Two days after I changed was when the PSM light, then check engine started to show up. (the air suspension light was already there before the wheel change).

Any thoughts will be of great help.

Thanks,
cpa

Couple of thoughts.

The tire size setting is super easy to change via the wiper stalk controls in the dash menu system. Should take about 30 seconds to do next time you sit down in the car. (car must be stopped for this one).

Is your car a dual battery car? Did you replace only one of the batteries?

I did the wheel alignment on Friday morning. Some adjustments were performed. Front wheel Amber and rear toe. And the mechanic worked in dealer before. I asked him regarding these problems. He suggested regarding the cel p0016 cam/crankshaft , since it comes and goes and the ride feels normal it is not the problem of the sensors themselves. Rather it should be the problem of the correlation of the positions of these two shafts. And since the truck is 100k miles now the timing chains start to ware and lose. This shift the phase/correlation a bit and triggered the alarm. He also suggested when the problem become perment I should get the chains changed. Three in total. All these were based on his experience since when my truck was there the cel light did not show up so there were no way to scan it.