2001 Mercedes Benz SLK320

CAR DRIVEN NORMALLY ON COLD, CLEAR NIGHT. ROAD CONDITION WAS FAIR (DRY FROM CENTERLINE TO TRAVEL LANE MIDPOINT W/ HARD-PACKED SNOW FROM THERE TO SHOULDER). EXPERIENCED A VIBRATION, SQUEALING NOISE & SLIGHT PULL TO RIGHT. STOPPED TO INVESTIGATE POSSIBILITY OF BLOWN TIRE. FOUND NOTHING WRONG AFTER VISUAL INSPECTION, SO RESUMED DRIVING. APPROX. 15S LATER, SQUEALING, VIBRATION & SENSATION OF PULLING TO RIGHT RETURNED, THEN CAR WOULD NOT RESPOND TO THROTTLE INPUTS & SLOWED FROM 40 TO 25MPH. CAR THEN SHUDDERED VIOLENTLY W/ LOUD SCREECHING NOISE, SNAPPED TO RIGHT & LOST CONTROL. ATTEMPTS TO COUNTER STEER WERE INEFFECTIVE AS CAR SLID ON HARD-PACKED SNOW FOR APPROX. 100' & STRUCK SNOWBANK AT 20MPH. FORTUNATELY SNOW WAS VERY LIGHT, DRY AND FLUFFY & DECELERATION WAS REASONABLY GENTLE. NO MAJOR DAMAGE OCCURRED & AIR BAGS DID NOT DEPLOY. AFTER EXTRICATING, CAR COULD NOT BE DRIVEN. AN OBSERVER STANDING OUTSIDE THE CAR NOTED FRONT RIGHT WHEEL WOULD ROLL FOR A FEW FEET, THEN LOCK UP. SHUT ENGINE OFF & RESTARTED (ATTEMPTING TO RESET SYSTEMS). AT THIS POINT BOTH 'BAS ESP' AND 'ABS' WARNING LIGHTS ILLUMINATED (THEY WERE NOT LIT PREVIOUSLY). CAR STILL COULD NOT BE DRIVEN - FRONT RIGHT WHEEL WOULD LOCK UP AFTER A FEW FEET OF TRAVEL & HAD TO BE TOWED AWAY. LATER DETERMINED INCIDENT CAUSED BY YAW SENSOR FAILURE. FRONT RIGHT WHEEL HAD BEEN LOCKING & SLIDING ON HARD PACKED SNOW THEN SUDDENLY REGAINED TRACTION WHEN IT CROSSED A DRY PATCH OF PAVEMENT, CAUSING THE RAPID DIRECTIONAL CHANGE & LOSS OF CONTROL. VERY DANGEROUS. IF CAR HAD HIT A TREE, PARKED CAR, ETC. INSTEAD OF SOFT SNOWBANK THIS WOULD HAVE BEEN A SERIOUS CRASH LIKELY W/ INJURY. UNACCEPTABLE & UNSAFE! PLEASE REOPEN INVESTIGATION! THIS IS A POTENTIALLY VERY DANGEROUS SYSTEM! SENSORS SHOULD CONTINUOUSLY SELF-CHECK & SHUT SYSTEM OFF COMPLETELY IF FAILED. THIS WILL KILL SOMEONE EVENTUALLY IF NOTHING IS DONE! *TR