jeff spahn

I took mine to the dealer. Had a bad valve somewhere in the rear. Didn't have time to mess with it.. They fixed it and recalibrated. About $1200.

Not_Sure

I finally got a chance to get it in and start investigating.

first i checked the relay and swapped it out, Nothing.
then I went to the compressor. I put power directly to it from my battery charger. and it ran. only could run it for about 20 sec before the charger would cut off to cool down (was on Start 50a setting) when i would cut power I could hear a brief "pshhhhhh"

so i didnt know if it was running while the car is running, since its not that loud.

next I went to remove the pump, and started removing the air pipes. The rear L/R pipes let out a decent amount of and air and the rear end started to lower. The front Pipes no pressure (as expected) the i removed one from the tank, and it let out qutie a bit of air, about double what each rear strut let out.

after i got the pump assembly, I didnt see any broken lines or fittings. I again put power the the pump and a decent air volume was coming out of the brown tube. I will say the elbow fitting felt a little loose as there was no resistance to rotating it.

any thoughts on where to look next? can I swap around the pipes and see if the pump will inflate the front struts?

v10rick

The pump motor runs on PWM, not straight DC.

Google search PWM for details.

Be careful when powering the pump motor with a battery or charger, the motor could overheat and be damaged.

It takes a few seconds to set the suspension height, when everything is functioning and there are no leaks.

Not_Sure

Ok but since the pump does work, what the next likely place to check?

PourBoi-Jay

Replace the air valves on each strut

Not_Sure

also, if the distribution block is the issue, would the computer simply tell the pump not to run?

Not_Sure

I was just thinking, I have another cayenne, with air suspension that works. is there something i can easily "swap to test" such as the computer?

JAGMAN1

I’d swap the pump and/or valve block. IS the pump getting 12v?

And if you have all new struts, I’d stick with the air suspension.

Not_Sure

I didnt check if its getting 12v, but I just plugged it in and left it hanging, to see if I could hear it run, and it did not.

but if the valve block was bad would, that stop the motor from running?

na2ub

From what I understand, if both sides of the rear or front are low, it's a valve block problem. If a single corner is low, it's a strut problem.

v10rick

The pressure sensor is in the valve block. Do you have a scan tool to read the pressure?

Not_Sure

No I dont have a tool, kind of tight on budget.. at the moment, plus I was hoping it would be fairly easy to figure out.

However pressure should be zero at the moment.

So heres what I did so far. I pulled out the computer and checked for solder cracks. found 1 maybe 2, and re did them. that made the system, kind of work, it at least responded when i hit the button and showed the level, which it didn't do before. but then the first "up arrow" on the switch stayed on. So I went over to Cayenne #2 and pulled the computer out of that one; I plugged it in and it seemed at first to work a little "more" as it didn't give an error at first......but the compressor still didn't come on

Next just for the heck of it, I checked the relay, I pulled the cover off the relay and it looked ok. So after putting the compressor back in place. I plugged in the relay with out the cover on so i could see if it worked... And it never activated. SO for the heck of it I manually closed the relay. THEN the compressor came on! I let it run for about 60 sec, didn't notice any change, ran it for another 60sec, but still no change. (but with an empty tank I don't know how long it would take) I was kind of hoping I could get some pressure in the system to raise it off the bump stops to make it driveable.

Not_Sure

Also can anyone clarify if the doors have to be closed for the air suspension to work, i read that on another thread, but im pretty sure i heard the pump running on the other Cayenne with the door open.

And will the pump ever run with out the engine on? would be great if I could not have to start the car 20 times each time I mess with this.

JAGMAN1

Yes, doors and tailgate must be closed for the system to regulate height. The pump can run with the doors open, but that is just refilling the accumulators.

Engine running can’t hurt…

Not_Sure

Ok I picked up a scanner, heres what it told me

0778: no signal/com steering angle sensor
1397: Open/short circuit to ground vent solenoid valve
1400 Below lower limit exceeded control position not adjustable ( I assume this is because its fully bottomed now)
0668 Open circuit/short to ground vehicle voltage terminal 30
4780 mechanical fault vehicle level sensor


what do you guys think?