So, last month I ran my stock '05 996 TTS at VIR. I left the stability management (PSM) on and noticed it fighting me, so I turned it off. Now during daily driving with PSM on, particularly going around corners such as on-ramps and off-ramps, the PSM kicks in what at what seems a lot more than it should. When I say it "kicks in," I mean that I can feel the anti-lock braking system activating slightly to slow me down, with the PSM light coming on. This is with road tires and I am not squealing the tires at the time. Any thoughts? Is the PSM malfunctioning?

Thanks,

Rick

 

Have you recently done any suspension work or lowered the car? Steering sensor probably needs recalibration if you did.

 

Any tire changes?

 

I had the same problem at the beginning of the season. I've decided to bleed the brakes properly with PST2 and the PSM pump activated and it eliminate completely this PSM intrusion....

 

How do you bleed the brakes "with the PSM pump activated"? I got the same problem right after mounting new rear tires. Over time got worse and worse. After about 3,000 miles, my ABS failure and PSM lights come on all the time and I just now got a read out that says my abs pressure switch is faulty. Dealer wants $900. Used places want to sell me a whole new pump with swith included for about the same price. Anyone have any ideas ?

 

were your tire sizes the same? ( stock? )

i just switched out rears also, and also got that abs/psm fail cel, but i switched to a 315/30 from the stock 295. haven't seen the cel since and i haven't cleared the code. maybe the car sensed the size differential and then adjusted?? i've driven hard and gotten the psm to activate but no more CELs. strange.

at least you know what your cel meant.

 

PSM is pretty sensitive in these cars. My rear Michelins wore out, so I figured i just change out the rears and not the fronts. I did go to another brand, as soons as I put on the good rubber in the rear, the PSM would kick in. I then changed out the fornts to the same brand, and no PSM. One can only summize that either the sidewalls were different between the two brands, or the new rears had just enough tread, larger profile to kick in the PSM, since the PSM monitors wheel speed. Anyway all four stock sizes of the same brand, car doesn't kick in the PSM. Never got a cell!