Resetting the throttle position on a BMW E46 requires You to enter the car and turn the ignition on. When doing so, make sure to put Your foot on the brake and push it down when turning the ignition on. At this point, only the cars accessories should have booted up. When this happens, push down the accelerator as well. Hold it down for roughly 20 seconds and then release the accelerator and turn off the car, to complete the reset. If Youre having trouble doing this procedure, consult Your owners manual. It should contain a detailed breakdown of each step, as well as a walk-through to reset the throttle position sensor.
try this, it’s for an older 3 series, but it should work on the 1.
to check the alternator and battery, start the car and put a multimeter on the battery terminals.
you should see a voltage of around 14v dc.
switch the engine off and hopefully the battery will show around 13.4? V dc.
go back and test the battery in about 30 minutes and it should read the same. This will show the alternator and battery working and holding charge. Anything around 12v, replaced the battery.
my x5 was going into limp mode and throttle position abnormalities due to a failing battery.