BMW E60 battery positive cable feed-through and recall
What is the problem with the E60/E61 battery positive cable feed-through?
The aluminium power cable runs through the feed-through to the underside of the car. Oxidation forms between the aluminium conductor and the connecting piece, increasing resistance and heating the connection. Most fires have started while the car was parked.
What does BMW's recall involve?
The cable's bolted connection is checked, the plastic cover is renewed if necessary and the connection is greased. The cable is not replaced. A BMW dealer can see from the system whether the action has been done. An imported car may not get a letter, so it is worth asking about it yourself.
How is an oxidised connection detected?
Resistance measurement alone does not reveal slight oxidation. A better measurement is the voltage drop during starting: in an intact cable it is in the order of millivolts, in an oxidised connection a couple of volts. Have a workshop do the measurement and the repair.
What does fault code 9AFF mean?
The code indicates that the resistance of the battery positive terminal is too high. Check and clean the positive cable connections and the feed-through connection. Once the contacts are in order, the code usually goes away.