iTrader: ( 0) E91 Can't Lock/unlock doors even with physical keys. Hello everybody! As the title says I have a really big and frustrating issue. My key fob starts the car normally, and I can lock the car with the button on the dash so my central lock is working in my opinion. I experience this with both of my keys.

This will help you if you need to change the key battery in this type of BMW key. It is a CR2450 battery.Buy your Car Key Battery on Amazon - Click on the fo Step 2: Open the fob. Using a small screwdriver or another flat object, insert it into the little slot that the key fits into and pop open the fob. Step 3: Remove the green circuit board. Carefully remove the circuit board from the fob, being sure not to damage any of the components. Step 4: Replace the battery. Clearly the rechargeable battery was nearing the end of its life. Here's how I replaced the battery. First you need to open the case. It's glued shut so you need to separate the two halves. Start at the back and work forward. It's easiest to separate the fob at the key ring hole. Use a small screwdriver and push it forward.
turn key to position 1 five times, remove key, hold unlock button then press lock button 3 times, release unlock button. Not that I know of. You shouldn't need to reprogram it though. Unless you have a different fob all you need to do is recharge the battery inside by having it in the ignition and running the car.
The battery in the key is only there for the remote key functions (lock, unlock the car, roll the windows down, pop open the trunk & the panic alarm set off). Sometimes when the key is opened up, the tiny EWS chip will fall out & without that, the key will not start the car. Without the EWS chip, the key can not talk to the EWS module & tell ePU1tH. 145 32 81 492 302 351 215 323 37

bmw e91 key battery replacement