Intermittent alarm for PSD
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From: Insane Diego, California
^^^ on my version of JF's wheelwell cover for the GTS, it is two half pieces mated together, with no small access hatch area dedicated for the PSD unit.
Easy to remove and install with metric sheet metal bolts and reusable plastic rivets.
Quite ingenious, really.
Easy to remove and install with metric sheet metal bolts and reusable plastic rivets.
Quite ingenious, really.
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From: Mostly in my workshop located in Sweden.
The Porsche GTS wheel well liners can be found here on page (Bildtafel) 801-27.
http://www.porsche.com/all/media/pdf...95_KATALOG.pdf
Åke
http://www.porsche.com/all/media/pdf...95_KATALOG.pdf
Åke
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From: K-town, Germany
The Porsche GTS wheel well liners can be found here on page (Bildtafel) 801-27.
http://www.porsche.com/all/media/pdf...95_KATALOG.pdf
Åke
http://www.porsche.com/all/media/pdf...95_KATALOG.pdf
Åke
928-504-304-04
928-504-303-04
Surprisingly under $400 ea on a couple Porsche dealer websites.
I don't know when the original covers turned into Pringle potato chips, but the set I bought from Rog are still nice and flexible--I'd say the same as when I bought them 4 years ago. So maybe they're using a different compound now.
Anyway, congrats Fred for solving the error code. You've motivated me to flush mine this weekend.
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From: Oman
Now when I start the car and back up out of the garage, within a few seconds I now get an alarm on the dash indicating "diff control not working". If I accept the alarm, the warning on the annuniator panel dissappears and I get no residual warning lamp elsewhere on the dash to tell me something is in a "state of alarm" condition.
However it seems that the PSD operating [green] lamp comes on if I hoon it. Now I have no idea what I am looking for. If anyone has any suggestions most appreciated- my friend at the dealership wil be back on duty tomorrow - doubtless he will have some ideas as he still retains a lot of 928 knowledge. Could it be that the alarm is in the memory and flashes up upon starting and will continue to do so until the error code in memory is deleted by interrogation with the hammer?
I had a problem with the airbag warning when I inadvertently powered up the system with the airbag disconnected- could not get rid of that warning until they put the hammer on and cancelled it.
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From: K-town, Germany
Fred - Are you sure your PSD is locking-up and actually working? That green light just means a different speed/rotation was detected between the two rear wheels. As example, you can remove the relay in the spare tire area and you'll see what you're experiencing--the "differential control is off" will light up; and if you drive up on a curb with one side of the car, the green PSD light will come on. But with the relay removed, it's definitely not working.
Probably tuff for you to check considering where you live, but spinning tires in a wet parking lot before a store opens is my favorite. You can definitely tell when it kicks in and the differential locks-up. Maybe do a burnout at the carwash
Probably tuff for you to check considering where you live, but spinning tires in a wet parking lot before a store opens is my favorite. You can definitely tell when it kicks in and the differential locks-up. Maybe do a burnout at the carwash
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From: Oman
Fred - Are you sure your PSD is locking-up and actually working? That green light just means a different speed/rotation was detected between the two rear wheels. As example, you can remove the relay in the spare tire area and you'll see what you're experiencing--the "differential control is off" will light up; and if you drive up on a curb with one side of the car, the green PSD light will come on. But with the relay removed, it's definitely not working.
Probably tuff for you to check considering where you live, but spinning tires in a wet parking lot before a store opens is my favorite. You can definitely tell when it kicks in and the differential locks-up. Maybe do a burnout at the carwash
Probably tuff for you to check considering where you live, but spinning tires in a wet parking lot before a store opens is my favorite. You can definitely tell when it kicks in and the differential locks-up. Maybe do a burnout at the carwash
Your point is rather interesting in that it differs from my [possibly erroneous?] perception in that I understood it to imply that the system has detected a slip condition and is applying a [non specific] amount of lock up somewhere within the proportionality range it is designed to progressively apply- thus feedback that the system is healthy.
As an engineer with a systems design background I would be astonished if Porsche designed the system as you describe if the system was not healthy but to be clear, nothing surprises me too much with these cars unless you can repair it for less than $1k -
Trouble is once you are on a slippery surface it is difficult to know whether one wheel is slipping or both of them or at least it is for ******** like me!
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From: NW Arkansas
The green PSD light in the dash will illuminate any time the ABS/PSD control detects rear wheel spin. Before I replaced my pump unit with one that wasn't full of water and non-functional that light would come on any time I spun one of the rear wheels. My ***-umption was the light triggers anytime the PSD "should" be engaging regardless of actual status. This aligns with my understanding of CTO (Compulsive Teutonic Over-engineering) in that you should get a notice if your rear wheels are spinning even if the system that is supposed to take care of that for you isn't working.
Have you cleaned the lateral acceleration sensor under the driver seat?
Mike
Have you cleaned the lateral acceleration sensor under the driver seat?
Mike
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From: Oman
Kindly educate me as to what there is to clean with the sensor- only thing I can think of would be the cable contacts.
My concern here is that after the flush everything was fine and working and now I get this alarm on start up.
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From: Oman
Thread Starter
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From: Oman
Just came across your thread with a faulty speed sensor although it would seem strange that such should happen just after a PSD flush and not having touched the sensors in the process unless a faulty front sensor can cause this..
Took the thing for a test run this afternoon and pushed the cornering on a couple of nice twisty sections but with new rubber and my wide wheels one has to be pretty maniacal to get it to squeal. I managed to get the PSD lamp lit on one bend but whether or not it was actually doing anything no clue. Were it not for the PSD lamp I would never know whether it was doing anything or not.
I was surprised to learn that the PSD lamp does not mean the diff is locking up, just an indication that its services are needed, but even so the car was rock solid and I had a stupid grin.
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From: NW Arkansas
The lateral acceleration sensor is mounted to the floor underneath the drivers seat with one or two screws. It is a small approx. 2" x 2" x 1" unit with a three wire connector. Remove it from the car and pop open the cover. Gently spray it clean with some electronics cleaner and ensure the small pendulum is free to move. Be gentle with the internals as it is quite sensitive and delicate (and $2000US to replace.) Since it is a type of magnetic pickup the system gets gunk-ed up with fine ferrous particles that impede the motion of the pendulum until the pendulum gets stuck to one side or the other. The PSD control interprets the resulting signal as "not plausible" and sets a system error.
Mike
Mike
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From: Oman
The lateral acceleration sensor is mounted to the floor underneath the drivers seat with one or two screws. It is a small approx. 2" x 2" x 1" unit with a three wire connector. Remove it from the car and pop open the cover. Gently spray it clean with some electronics cleaner and ensure the small pendulum is free to move. Be gentle with the internals as it is quite sensitive and delicate (and $2000US to replace.) Since it is a type of magnetic pickup the system gets gunk-ed up with fine ferrous particles that impede the motion of the pendulum until the pendulum gets stuck to one side or the other. The PSD control interprets the resulting signal as "not plausible" and sets a system error.
Mike
Mike
Thanks for that - I'll take a look at that and the wheel sensors tomorrow if I can. Thanks goodness John Speake has an alternative solution if needed. No idea if I still have the spare from my S4- I doubt it.
Seems strange that the problem has reared its ugly head at this time though.
Does the seat need to be unbolted or is there sufficient travel to uncover it?
Might be useful if anyone has a pic of this item.