No, despite what my signature says I don't drive a Pinto.

I have an '04 X50 with 46k miles on it that has been meticulously maintained. I bought it used with 28k miles on it, and yes, I've had some significant issues, but nothing major to the car (blown alternator, blown nav unit, blown oil cooler o-ring requiring dropping the engine). Thank god for the extended warranty. The car is stock other than a set of 19" HRE's with Hankooks and a GT2 MA Shaw front bumper conversion.

I'm a car nut. I've pulled tranny's and engines and there's nothing on a car I haven't done, but this one has me stumped. My last Porsche was an '01 C4 I bought new and put 45k miles on as a daily driver, so I know these cars pretty well.

A few days ago at about 100 mph on a downhill stretch with tight corners, I hit a small patch of sand/gravel and the right front wheel and the PSM acted really weird and the car threw a flashing CEL right away. I shut it off and coasted to a pull off. I looked everything over and it was perfect. Restarted the car and it was fine. However, within a few days after this, I had 2 more occurences of weird stuff with the front right wheel. If I wasn't a car nut, I never would've noticed, but both times I was doing 100+ through corners and that wheel didn't act right when it slipped a little. I've done several hundred miles since then with only this happening and no other issues. These other occurences didn't cause the car to throw a CEL or anything.

Has anybody had any issues with the PSM/wheel sensors like this? I'm suspecting the larger wheels combined with a bad sensor are doing it. I've done over 10k though with these wheels and drive my X50 hard and have never had a single issue.

 

Check your tire pressures first. A later step could be to reset the steering sensors (about $100 at Porsche).

For those with PSM issues on 19'' wheels, some info but not sure a solution (although my own problem seems to have disappeared ever since I put some air in my tires that were low due to cold weather).

https://www.6speedonline.com/forums/...-psm-help.html

https://www.6speedonline.com/forums/...-ring-etc.html

 

Thanks Mike, that helps, but I don't see anybody reporting a flashing CEL from this, just PSM/ABS warning lights. My tires have about 10k miles on them and the rears are going to need replacement very soon, but the fronts are fine. On a side note, I thought the Hankooks would give better mileage than stock tires, but I only got a few thousand more out of them.

I'm assuming the ECU stored whatever codes were thrown when it happened so a dealer can pull them. I assume my OBD device can't read them since the CEL is off, but I haven't honestly checked. I have a weird hesitation issue from the engine when driving conservatively that I need to have checked anyway before my warranty runs out.

 

propably when you hit the wheel maybe change for some degrees
the sterring geometry and because there is the angle sensor on the
sterring wheel in a specific speed it read wrong.
i think you must to restart the psm in a porsche dealer.

 

1. post your EXACT tire sizes.

2. There have been prior reports if weird (and troubling) DSC interventions from folks on the track (from memory)...

A

 

I have Hankook V12's on HRE P43R's.

Tire sizes are 305/30/19 and 235/35/19 (I think, not sure). I've searched the forums before and the tire sizes I'm running are the major consensus. Maybe they're a 40 aspect ratio on the front.

But I've run these for 10k miles now without a single issue. Is it possible the wear patterns have gotten the front/rear diameters out of sync that much? But I still don't understand how that translates to a flashing CEL and not just an ABS/PSM warning light.