| Issue ID | 861994 |
| Internal NHTSA # | 10404438 |
| Manufacurer | BMW OF NORTH AMERICA, LLC |
| Brand | BMW |
| Model | M3 |
| Model Year | 2003 |
| File date | 01/06/11 |
| Component | POWER TRAIN:AUTOMATIC TRANSMISSION |
| Product type code | VEHICLE |
| Description of the problem | 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. |
| Vehicle Mileage at Failure | 78960 |
| Number of Occurences | 1 |
| Source of the issue | NHTSA WEB SITE |
| City and State | CHARLOTTE, NC |
| VIN pattern | WBSBL93423JXXXXXX |
| Was vehicle invloved in a crash? | N |
| Was vehicle involved in a fire? | N |
| Was incedent reported to police? | N |
| Was medical attention required? | |
| Was part original equipment? | |
| No. of injured persons | |
| No. of fatalities | |
| Date of purchase | 07/08/26 |
| Was original owner? | N |
| Anti-lock brakes | N |
| Cruise control | N |
| Number of cylinders | 6 |
| Drive train type | RWD |
| Transmission type | |
| Vehicle speed | 35 |
| DoT tire identifier | |
| Tire size | |
| Location of tire code | |
| Type of tire failure code | |
| Was defective tire repaired? | |
| Date of manufacture | |
| Type of child seat code | |
| Type of restraint | |
| Dealer's name | |
| Dealer's telephone number | |
| Dealer's city | |
| Dealer's state code | |
| Dealer's ZIP code |