NHTSA Complaint #10404438 — 2003 BMW M3

AS YOU REMEMBER, WE ALL SPENT ABOUT SIX MONTHS THIS PAST SUMMER FIGURING OUT WHY OUR E46 M3 SMG'S WERE RANDOMLY THROWING ON THE TRANSMISSION CHECK LIGHT AND RANDOMLY CYCLING INTO NEUTRAL FOR AROUND 6-15 SECONDS, DISPLAYING A CONSTANT "0" DURING AN UP OR DOWNSHIFT IN HOT AND/OR HUMID WEATHER. WE DETERMINED AFTER PLENTY OF RESEARCH AND PHYSICALLY REMOVING THE SMG'S HYDRAULIC CONTROL UNIT(HCU), AND COMPARING HARD-TO-FIND BLUEPRINTS OF THE UNIT WHAT THE MALFUNCTION WAS. THE PROBLEM WAS THE HCU'S HYDRAULIC FLUID TEMPERATURE SENSOR, WHICH WOULD GO BAD DUE TO A THIN-LAYERED RESISTOR INSIDE THE SENSOR THAT WOULD MICROSCOPICALLY BEND AND CONTRACT OVER TIME IN AVID HEAT/HUMIDITY SITUATIONS, AND SEND FALSE DATA TO THE CAR'S TRANSMISSION CONTROL UNIT, GIVING IT THE ILLUSION THAT THE HCU WAS OVERHEATING AND NEEDED TO BE SHUT DOWN. TO THIS DAY, I AM STILL PUZZLED AS TO WHY BMW WOULD PROGRAM THE CONTROL MODULE TO DO SUCH A THING, KNOWING IT WOULD TEMPORARILY MAME THE CAR'S ABILITY TO ACCELERATE AND/OR MAINTAIN SPEED, AND THUS ENDANGER IT'S OCCUPANTS AND THE SAFETY OF OTHER MOTORISTS AROUND IT. *TR