Two problems related to wiring have been reported for the 2003 BMW 5 Series. The most recently reported issues are listed below.
While driving, the car suddenly shut down and lost all power. Had to pull over to the side of the road quickly to avoid an accident; had this been at high speed, the situation might have been worse. Subsequently when trying to start, the car shows a myriad of warning lights and faults. A fuse for the main computer (dme) had blown, due to a wiring short between the electronic thermostat and the main computer. Replacing the fuse is not a permanent fix, as it blows shortly after each time the car is started, rendering the car undriveable. This fix to replace shorted wiring is in the thousands of dollars. The car had been meticulously maintained and had never suffered any related issue before. There is a poor connection, faulty wiring, design flaw, or the like in this system.
Intermittent engine shut-down. Engine shuts off while vehicle is in motion at any speed. "engine failsafe" warning light comes on. Vehicle must be stopped, key turned off and re-started. This is a serious safety issue that BMW is aware of and has issued a related TSB. $2000 plus repair bill for a new "engine wiring harness". BMW should be recalling these vehicles.
| Wiring problems | |
| Electrical System problems |