96redLT4

Sorry if you guys are getting sick of hearing about my car, but I had to start this thread to get some eyeballs after my 5 page thread below 'my troublefree streak is over'. After the dealership replaced my bearing and wheel subharness, now I seem to be having a minor ebrake issue. When the brake engages or disengages there is a 'stutter' in the middle of the normally smooth cycling and sort of a 'ratcheting' sound in the left rear where they were working. The dash indicator and ebrake button light flash for about 5 sec before going off. Usually they are on solid when the brake is on and off when it is off. Service manager looked at it with me before I left but did not have an answer except to comment that maybe the car is getting 'confused'. The brake seems to hold on a hill though not sure if I trust it. Any ideas? I just got my canned email from the dealership making sure I had a great experience and to be sure and fill out the survey from Porsche.
Jim

Larry Cable

clearly - its not fixed

96redLT4

Car sure is pretty to look at though Larry. And, not burning any oil. I'm trying to look on the bright side. Best.
J

Larry Cable

I feel for you! I wonder if they simply did not adjust the ebrake calibration after doing all the work on that hub?

Larry Cable

curious, how does it behave when you use the auto-off feature, you know, put it in gear, put your seatbelt on and drive off ... does it disengage normally.

I'm a bit confused and surprised that the dealership let you drive the car away with it exhibiting this
behavior which is clearly not 'normal' in an area where they were working ...

96redLT4

Auto drive off feature is functioning correctly. I think the service manager was so overworked and just sort of threw up his hands. Maybe you are correct that there is a recalibration or adjustment necessary when you reinstall the parking brake which they did with the repair. I'll try to post a picture of the description of what they did with the repair as it sounded quite complex.
Jim

neanicu

Post what they've done to the car. There are several members on the GT4 forum that have had problems with the Ebrake. It works just fine,but the light will stay on at times. I'm with Larry,it's probably software related. Just drive the heck out of the car and don't worry. Take it back to them at your convenience,they should be able to fix it while you wait.

96redLT4

Hi neanicu. I thought you might be interested in their diagnostic procedure. Here it is. Maybe they just did not adjust it right on the re installation.

neanicu

There should be another page. It seems that the technician's description stopped abruptly because of lack of room on the page.

The technician is saying that he was getting a speed sensor error on the PIWIS from the rear driver side. Then he goes on saying he swapped sensors and bearing from side to side to see if the error moves. This part I doubt...that's not an easy undertaking and it's something a DIY-er might do,not an experienced technician using the latest scan tool. Of course he ended up measuring resistance(which he should've done from the beginning) and it was low on the affected side. He then replaced the harness.
If he indeed ended up taking all that stuff apart,then he most likely had to play with the parking brake,which might be the reason it is not working properly...

Noah Fect

Actually, there's not a lot you can read into the difference between 4.5 and 5.5 "mohms", regardless of whether the tech meant "megaohms" (M) or "milliohms" (m). Tiny differences in contact resistance could easily account for the latter (except that even a few inches of wire would have more resistance than that), while meaningless differences in semiconductor junction leakage or bias characteristics would account for the former.

What you can read into it is, "Hmmph. This gadget isn't telling me exactly what's wrong, therefore I'm going to try random stuff until either the car starts working or 5:00 rolls around."

Karl911

I had my wheel hubs replaced too, a couple of months ago also.
And I got also sorts of alarms about my e brake.
The long and the short of it was that my E brake pad gap need to be recalibrated 😳

96redLT4

This is the second page. I could not get it to load initially. Not much extra here. I sure sounds like electrical engineering 101. I was actually impressed by the description, but as you say if they actually did all that. He said they actually spent about 9 total hrs working on it.
Jim

96redLT4

I bet this is my issue now Karl is that the ebrake needs to be re-calibrated or adjusted after the re install. Why did you need your hubs replaced?
Jim

96redLT4

Yes strange that a sudden change would happen at 2500 miles and that 4.5 would cause everything to go haywire when 5.5 was fine. I was sure glad I had not modified anything, new wheels etc, or they would have blamed it on that. When they first started looking at it, the service advisor's first thought, rats chewing on the wires.
Jim

Karl911

42K miles on the Car , including 45+ track days, one set of PCCBs.
I lost count of tires and brake pads!
Also knock tire off rear wheel figure I should just do all of them,