That is an easy one and wants to be sorted asap before it locks you out and immobilises itself. It is caused by a dying microswitch in one of the front door latches. 3 of the 4 doors will lock, the one that doesn't is the faulty one.

Are you saying that I should check which ones are locking when they start locking and unlocking on their own?

Yes, one won't be locking and that is the faulty one.

I will have to wait until the weather warms up again as they chatter lock and unlock when it is warm. Perfectly alright when the weather is cool.

If I was a betting man, I would say it will be the RHF latch that doesn't lock/unlock with the rest, and therefore is the one causing the problems.

It seems to be the most common one, and my theory is that because the tailgate motor grounds through the CDL switch in the RHF door. The switch contacts are only rated at 0.1A, which is fine for logic signals, but I feel it's a bit low for the motor ground. Which is one of the reasons the RHF CDL switch in all my refurb latches is beefed up to 5A (not that the motor will draw anything like that - but gives some headroom, and it was a standard rating I could find).

Drivers door?

Drivers door?

Back to the problem in hand.

Used to car several times today, every time I started the app it was at the right height and the light instantly went onto normal.

All very strange. The only thing I did a few days back was use my sons code reader, instead of the Nanocom. Ever since I ran things through that it hasn’t missed a beat.

All very strange, considering it has been seriously messing around for the last several months on a regular basis.

I can’t remember the make that he uses, but we’ll find out tomorrow and post up.

Had to park it this morning on ground that was sloping two ways. This would have really upset it before and had me reaching for the Nanocom. No issues at all.

Hopefully will put this one to bed until it rears its head again…

They like to lull you into a sense of false complacency, then strike! (usually on a dark and stormy night far from home)
It should be fine now until you forget to bring the Nano with you.........They know!

Seriously tho' That is an odd one, and I would like to know why they can heal themselves. I have experienced short periods of the same type you have been suffering, and upon closer examination, the issues have cleared up. No cause and effect!
Good luck!

Well that didn’t last long. Yesterday evening went back to my car in Dorking and I could see it was sitting lower. It stayed at that height for the 4 mile journey home and that is where it remains.

Put the Nanocom on it, and it read the following

Unknown fault..
All four corner sensors Out of range.

That’s as far as I have gone.

Very strange, and doesn’t really help me with my very limited experience of the system.

Over to you experts, any ideas?

Hmmm....Don't park in Dorking?

Has anyone ever been able to get Collin and his merry men at BBS to tell us what an "Unknown Fault" is?
I get them whenever either of mine throws a wobbly. Clear them and all good again. It's nice that it tells us that there is a fault, but useless for diagnostics. What does RSW show these faults as?
As for somewhere else to look, Have you confirmed that the plugs on the EAS ECU are clean and tight?
All of the intermediate plugs that the sensor wires run through?

Since you have now had a 4 wheel fault, Is this yet another odd P-38 issue caused by a corroded or loose
earth point affecting the ECU? That could cause all four sensors to mis read.
Have you run through all of the earth points and cleaned them up? This, I have found is practically a basic service for these things and at 20+ years, and in your corrosive environment, could be due.
Bad earth point will cause all kinds of seemingly unrelated gremlins to randomly pop up (Like touch the brake and the radio goes off, and HVAC display blanks out)
Good hunting!

Thanks for that information.

I have never touched any of the earths or connectors. The only thing I did when I bought the vehicle was convert from springs back to EAS.
Luckily everything was in place on the car with all airlines capped off ready to be reconnected. EAS ECU was disconnected under the passenger seat, which of course I reconnected.

I’m in the middle of renewing all the radiator hoses on my Boxster at the moment, which is proving lengthy, (you have to drop the front subframe and renew various aluminium pipes as well as hoses with push fit, O ring connectors!).

I will get back onto the P38 in the next few days.

Thanks

The RSW software also shows a fault that means nothing, so I assume it is the same as the Nanocom Unknown Fault. I think the RSW says something like 'Vehicle has moved'. My money would still be on an iffy height sensor though.

If there is an iffy height sensor does it shut down the operation of the EAS completely - compressor not running, no attempt to achieve height. I always thought that once the system decided not to work it lit the EAS lights up like a Christmas tree and gave the slow 30mph (or some such) warning?

I should have asked, where should I check for the earths?

I don’t have any lights that come up on the dashboard but the pump definitely doesn’t work when you start up the engine and it needs to rise to normal level.

I did replace both front sensors for aftermarket ones a few months ago. The rears is original.

Funny that the last several days have been absolutely perfect!

A lot of people have had aftermarket height sensors fail in a matter of months so you may be another of them. I don't suppose you have the originals to put back in to try? It is almost as if you have two faults, one causing it to drop when left and another that causes the pump to not start. The fact that when one happens the other does too, would suggest the same fault but manifesting itself in two ways.

I may have retained the old ones. I will have a look a little later when I’m in the garage.

What the car is doing now is what it did before I replaced the two front sensors. So it seems that the fault may lie elsewhere, unless this is just coincidental of course.

For the pump issue, you need to work through the system logically.

If the ECU is trying to run the pump, check the relay & compressor wiring.
-- Bridge the relay & trigger the pump manually. Manual pump jumper
-- If there's 12V at the compressor connector, but it doesn't run, then suspect the motor brushes.

If the ECU shows intermittent compressor overheat, suspect the thermal switch wires. The wire is simply crimped to the PCB inside the pump & can become intermittent. See this video & look at the orange wire. The crimp becomes loose over time from vibration. All my pumps have this wire soldered for reliability !!

Think about when the ECU stops & starts the pump. It requires pressure switch to be open (i.e. low tank pressure), and the exhaust valve to be closed, (i.e. pump is off during lowering). Pump will run when the ECU is trying to raise the car.

I will go through your suggestions, thanks.

Had to use the car this morning. Suspension stayed low with the winking light trying to raise, winking! Suddenly after 2 miles, beeping from the dash, Warning symbol for EAS problem illuminates and all 4 lights start blinking. a minute later all 4 lights illuminate solid!

Switched the Nanocom and it states, "compressor is faulty".

Need to check power to compressor...

But first...Really having problems with the Boxster atm. Corroded pipe ends into plastic housings etc.. I'm into about £500 of pipes and fittings...