Medicopter

Thanks for confirming that. Your insights are very helpful.

Seedster

This thread was an absolute treasure trove of info - thanks to CDixon and all who contributed. It gave me the courage the tackle the FAL issue on the 7.2 GT3 I just purchased. The previous owner knew FAL wasn't working and bought a used known-working FAL and just never had time to install so I purchased it from him.

Symptom:
When pushing the 'lift' button on the center console, the button lights up...but nothing happens. No sound of the air pump, no error message on the dash, no lift, nothing. And after a minute or so, the light on the button just turns off with no message on the dash.

This is my first time working on a Porsche but thankfully removing of the FAL was relatively straight forward. I immediately pulled the pump cover off the original unit thinking it was the belt, which it wasn't. I fed 12V to the pump directly and it fired up...interesting. Instead of going into diagnosis mode, I figured I'd just throw in the known working unit I purchased from the previous owner and take my time fiddling with / trying to repair the original one.

Unfortunately, the known working unit did the same thing after installation.

Diagnostics Performed:
I checked all the fuses in the front left kick panel and, per post #238 in this thread, decided to look at the Rear Control Unit under the rear parcel shelf. The 40A fuse there was good but the "Lift Function Switch-Off" relay was missing which you can see in the pic to the left of the black #643 relay (which is the "Pump Lift Function" relay). The second pic shows the wires feeding into the missing relay which correspond with the colored referenced in post #204.

I went to the dealer, bought the missing relay and a new black "Pump Lift Function" relay. Came home, replaced both, and still nothing

I downloaded the Porsche-specific add-on for my Foxwell NT510 scanner and was able to find the 3 FAL test functions also mentioned in this thread (Activate Pump, Raise Car, and Lower Car). When running the Activate Pump feature, it immediately throws an error (error key 22, whatever that means). Raise Car and Lower Car say "funktion aktiv" when I run them but nothing happens.

I'm at a loss at this point and will probably need to take my multimeter and go to town trying to reverse engineer why I'm not getting a signal at all...nor an error on the dash.

Stupid question but does the car need to be down on all 4 wheels (it's on jackstands currently) in order to use/test the FAL functionality or is it supposed to work like normal when when the car is up in the air?

Any help would be greatly appreciated!

cdixon

Hi Seedster,

It certainly looks like someone that wasn’t sure what they are doing has been playing in the car previously… The fact that relays have been pulled and no alarm on the dashboard is interesting.

If it where me i’d break it into two areas of troubleshooting, the car and the FAL unit.

FAL Unit checks.

1. On your benched FAL can you try running the compressor pump for at least 1 minute and then apply some voltage to pins 1 and 2 on the six pin black plug on the FAL (Check the PDF I wrote and posted in an earlier thread as it has a circuit diagram of the FAL i drew up). These pins have black wires with green marking on them. This should cause the inflate solenoid valve to actuate and air to be blown out of the air holes at the front of the unit that connect to the shock absorber air chambers.
2. You can also repeat this stage but with a meter connected to the 18 bar switch, check to see if you can run the compressor until the 18 bar switch closes. This can take up to 3 minutes with some pumps. (NOTE in both these tests be careful actuating the inflate valve as it’s a lot of air pressure and can blow the FAL unit over if it is not secure)
3. You can apply voltage to all the solenoid switches (three of them) and you will here them clicking if good
4. The Suco pressure switches will require air pressure to actuate them.

Car checks.

1. First thing i would do is get under the car and check all the pins and wires into the three connectors, the two six pin valve and switch connectors are very fragile and wires can come out or pins get bent.
2. Do you have access to a PIWIS, as I think what you are seeing now is the remanence of someone trying to code it out in the past. The fact that you do not get the compressor pump firing on the car when it’s running or no error messages on the dash is fishy.
3. If not that then I guess the next thing to look at would be the rear control unit, but I would meter out all the wiring, plugs, and relays first as this unit is likely to be expensive.

To answer your other question. Yes the wheels need to be on the deck as it needs gravity to push air out the system when lowering…. Should be ok for raising the FAL though.

I’ll think about it some more and see if I can suggests anything else.

Good Luck, I’m sure it’’s something silly now.

Chris

JB911

I put my front wheels in the air and operated the FAL once, and also disconnected the lines from the shocks to see it work, air coming through. I put new washers on those banjo bolts just in case. But you have to make sure the doors are closed while up-

Maybe get a Piwis and re-code the unit(?)

JB

00 Scrub

I've got a non pump/valve related question for this thread. I'm re installing my FAL lines and was wondering if anyone had any pictures of what the OEM routing and mounting looked like.
Also does anyone have the workshop manual for connecting the lines to the struts? I want to make sure I get the correct torque for the banjo fitting.

Thanks

cdixon

As far as I remember not even the workshop manual shows you the routing of these airlines. It isn’t that difficult though. They are clipped along the coolant lines, then out through the front wheel arch liners. Also the manual doesn’t give any torque setting for the airline fittings. Just nip them up hand tight, on the shocks you require copper washers to connect the banjo bolts. These cost pennies so worth putting new ones on when ever you remove the banjo bolts.

If you look at my post #230 you will see the document that i wrote. take a look at the pictures in the first couple of pages, they show a graphical view

bonehead

Anyone have the part numbers for the FAL pressure switches?

JG 996T

Pretty sure I,listed in the other thread same topic

bonehead

Sorry, didn't have time to filter through this entire thread. But I just did during a lull in the office
Seems there is still some confusion on the part # of the 13 bar switch depending on the version of compressor??

I have an identical problem as most with a slight difference. FAL will go up without issue. Will sometimes get the LIFT indicator, sometimes not. FAL will go down with the button but only sporadically. One difference from others here that I noticed is that the FAL will go down by itself if I leave car parked in the up position (since I can't lower the damn thing with the button). I assume I may also have an air leak in the system in addition to a faulty switch?

JG 996T

I will email you my service record for that issue. has all the part numbers on it. i had same issue, goes up but not down w button

00 Scrub

Well I got my FAL activated today. . I don't get a "Lift" message on the dash nor does it go back down when the button is pressed. I did get a "Lift Malfunction" warning on the dash after a few minutes of driving. Thanks to cdixon and the others on this thread I am pretty sure the previous owner turned it off due to a faulty pressure switch. The documentation that cdixon put together is really well done.

I emailed Suco USA to get a quote on some of the preset switches. I was wondering if anyone had cut open a failed switch to see what was the actual failure mode. Was the mechanism getting gummed up or was the diaphragm/seal damaged from the hydraulic oil?

Also I was wondering if anyone had thought about putting an inline filter to catch any hydraulic oil to prevent damage to the switch.
Something like this: https://www.comoso.com/product/hydra...-inline-filter

bonehead

Let us know what Suco says about the switches

00 Scrub

bonehead, I called Suco-tech and they referred me to one of two distributors:

1. The Sensor Connection: http://thesensorconnection.com/categ...ssure-switches
2. Motion Industries: https://www.motionindustries.com/

I've got them trying to quote the switches now from The Sensor Connection. I'll let you know when they get back to me.
The lady on the phone at Suco-tech did say these were most likely special order with a 8-10week lead time.

bonehead

Thanks for the update! Lead time isn't an issue as long as they can deliver an OEM product (at a lower price). My FAL still goes up on command. Just decides to go down when it feels it's good and ready🙄

Wonderdan

Mine wont go down in park, but does go down when I exceed 30 mph or so. It's going in for a full lube in a few weeks, I'm going to see what crazy number Porsche will quote me. I did buy the PIWIS so I'll see what it says this weekend when i hit the button.