Car not starting first time after stuck rear hatch

[Stevo96]

Car is a 2004 3.0. It's been working perfectly until yesterday. I went to pick up a really heavy long item that required us to lay back the front seat fully. I also jammed the item in which put pressure on the lower tail gate, on top of that my keys to the car got jammed in between the tailgate and the car body as I shut the tailgate without knowing they were there. This all could have nothing to do with it but seems odd that the issue arose straight after this.
When I go to start the car the lights come on the dash but the starter doesn't engage, it's as if the car is immobilised yet on the 3rd of 4th attempt it starts ok. Sometimes i can hear the tailgate unlock/lock itself...
Any ideas? I've tried disconnecting the battery for half hour but no change

[wpoll]

How badly did you mash the keys? There's a number of circuits in the fob that control the engine immobiliser... and the tail gate latch.

[Stevo96]

I can't see any damage to the key.

[wpoll]

Originally Posted by Stevo96

I can't see any damage to the key.

In that case, have you a second set to try? Move the current set well away from car - other side of the house etc.

[Stevo96]

Nope, I don't have a spare key. Could it be the battery in the key fob?

[wpoll]

Originally Posted by Stevo96

Nope, I don't have a spare key. Could it be the battery in the key fob?

Not likely - or at least the car not starting issue is not related to the key fob battery. The security system in the key is not powered by the key fob battery - it is powered by an electro-magnetic field around the ignition switch. This same field also charges the (rechargeable) key fob battery.

The security system in the key deactivates the engine immobiliser function when the key is inserted into the ignition (and becomes powered by electro-magnetic field).

The key fob battery only powers the car's remote lock/unlock function - and the trunk lock function.

Despite the lack of any obvious external damage to the key fob, it really does sound like the key fob is malfunctioning. I know that even a single drop onto concrete can sometime render the key fob useless, so they can be rather fragile (although most seem to withstand extensive abuse!). Does the key fob still reliably lock/unlock the car?

I know on VW cars, there is a small red key icon on the cluster that goes out when the key is read by the car and the engine system are enabled. If the key is the wrong key or malfunctioning, the red key icon is on and the car won't start. I don't think I've seen the same thing on BMWs though, so I'm not sure how to diagnose this...

[andrewwynn]

I have had problems with more than one of my x5 keys. I had a similar problem with the car re-locking and it boiled down to the key button being stuck down. A broken solder joint in the immobilizing section of the key could cause a non start but it would have to re connect itself to allow a start. If you have only one key it's time to bite the bullet and get a new key. Then you can take apart the original or send it to the guy that will fix it for$60


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[bcredliner]

I agree to focus on verifying the key is working properly first. Start with- there are no coincidences in auto issues. It takes a few days to get a new key. And Murphy's law concerning BMW keys is if you don't have a spare key something will happen that can only be resolved with a spare key.

Your symptoms could also indicate the ignition switch is failing but that would be a coincidence.

[Stevo96]

Thanks guys. Best place to buy a new key? Is it the dealer? I'm in Australia..

[andrewwynn]

Only dealer. Probably as in the USA only one place makes all keys and overnights to dealer. Just need your title and drivers license (and a couple hundred bucks). I'm about to order one I lost my main key.


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