Whys doesn't my key turn on the engine?

facade

Some cars have the transponder as part of the circuit board with the switches on. It might need a good battery to work, I haven't tested that.

I did test on my Renault Nissan by removing the circuit board and it won't start.

And then I read in the manual that attempting to start it without a valid transponder 5 times bricks the ECU as a "security" feature!

So if someone tries unsuccessfully to steal the car, it has to go back to the dealer on a trailer as you can't start it with the proper key any more.

[Deleted User]

angrycrow said:

The flip key consists of three separate system.

Part 1 in the body of the key is the fob for the central locking and alarm if fitted. It does nothing to start the engine.

Part 2 the physical key blade, it opens the physical lock on the car and turns the ignition barrel.

Part 3 is the immobiliser transponder chip. When placed next to the ignition barrel it tells the car to turn the immobiliser off. Some look like a glass tube about the size of a grain of rice, others are sealed in plastic about the size of a little finger nail. The glass ones are very fragile.

I suspect either you are trying to use just the key blade on its own or the immobiliser transponder has fallen out. If you find all the parts and put the key back together it may work. 

Worst case is that you have broken the transponder chip in which case getting a new key programmed is the only answer. 

Thanks for this. I've tried the key with it put together and whilst apart. Looks like the transponder fell out. Took a quick look today and couldn't see anything. Then again, I was looking for something like a typical chip but from what you are saying it's nothing like that. Will take a closer look but have mentally accepted I have to probably buy a new one.

As the key isn't lost, do you know if they can program to the same settings so I don't have to replace both keys?

Ditzy_Mitzy

Same thing happened to our old BMW: the plastic bit of the only ignition key broke off the metal key blade.  We ended up having to order a new key via the main dealer, which had to be sent over from Germany.  In the interim we started the car by using a pair of pliers to insert the key blade in the ignition barrel and turn it whilst holding the broken plastic bit under the steering column!  It worked.  

To the OP: the transponder in the key is aligned to the immobiliser in the car; your new key will be married up to the existing immobiliser, which won't change in any way.  The old key will continue to work, therefore.