Key wont start engine
 

Hi guys, any ideas here!?
My key will unlock and lock the car but when I try and start the engine nothing! It works one week then not the other. :S

I know it is the key as my spare which doesn't have the remote locking starts the car every time. :dunno:


Cheers!

If the engine is not cranking (turning over) the transponder in the key is not telling the ews module that the key is the correct key for this car. Search the internet to see if there's a reinitialization procedure, if not the dealer is your only option to order a new key.

Interested to find out the answer to this as my wife's car has the same problem.

Both key fobs open the doors remotely, one key starts the car every time, the other key is temperamental, it will work for a couple of weeks then won't start the car at all. Then a couple of weeks later it will start the car again?

Is it something to do with the coded chip inside the fob?

Yep

There are 3 features in the remote keys and all are independent systems that work in conjunction and sometimes in tandem with each other...but all are completely different systems:

• EWS - immobilizing system...uses a transponder chip that communicates over a 125 KHz radio signal with the DME/EWS Control module/Ring Antenna (located around the ignition cylinder)/remote key. This feature is self powering (uses induction) and DOES NOT require the battery inside the key to work. But it can get out of sync with the EWS control module (the ISN rolling code)...which requires BMW diagnostic equipment (or aftermarket software/hardware) to communicate and set/reset or "sync".
• FZV - (fbzv) remote central locking...transmits a 315 MHz signal to a receiver in the vehicle which then sends that data to the GM to lock/unlock the vehicle. (requires the battery inside the key to operate)
• DWA - anti-theft alarm siren system...transmits a 315 MHz signal (433 MHz in Europe & some other markets) to a receiver in the vehicle which then sends that data to the GM to arm/disarm the vehicle. (requires the battery inside the key to operate)

http://www.bimmerboard.com/members/q...%20Bluebee.jpg

Awesome summary Qsilver7!

If the OP wants to send me a new chip key and their EWS, I can program it for them ;)

So what options do you have in this case?
How can you re-sync the key to the car? I have the same problem every now and then and I only have 1 key. I scanned the car with DIS and I have a EWS rolling code error.

Depends, if the key is faulty, new key. If the key is simply out of sync, you still need to modify the EWS to allow it to start again.

I bought a new key and coded it. Problem solved. I also didn't like that fact that I had no spare key when I bought the car.

Strange that it happens one week but not the next! If i could just rip the bl00dy EWS out i would!!
So i really need to go see a key specialist with and get the EWS re-synced? :(

Not a key specialist, a BMW dealer.

And while you're at the dealer order a SPARE key! Better to be safe than sorry. Trying to get a new key when you've lost or locked your only key inside the vehicle is a frustration you can remove now from you life without having to go through the experience.

You do NOT have to buy another expensive REMOTE key for back-up. There are non-remote keys that cost 1/3 to 1/2 the cost of the remote keys. Ask your local BMW dealership's Parts Dept how much the BMW keys below cost (give them the 11 digit BMW part nbr for #1, #3, and #5):

1. #1 is a metal blade spare key (approx $50)
2. #2 is a plastic "valet" key (approx $40) works the ignition & door only...will not open glove box
3. #5 is the remote key