Keys, difference between standard and spare. (1 Viewer)

[Altespace]

Hi All,

Will on a trip, I dropped my key and the already flimsy hosing broke in two and all the electronics fell out.
No time to do a proper fix, I set the electronics aside and tapped the housing together.

And the next thing really intrigued me, and I hope someone can explain this to me.

The key that was tapped back together doesn’t start the car. It cranks, but doesn’t start.
Luckily my wife brought the spare key along. This one doesn’t have any electronics, and it starts the car without any problems.

Can anyone explain to me what is the difference between the two keys?
Why does the one key need electronics and the other one not.

Thanks

 

[smoltz]

Your assumption that the the spare key does not have electronics is incorrect.

A key for the 100 series (I will assume you're in the US) has 2 or 3 pieces as it pertains to function....
- The metal key blade (all keys)
- The transponder chip (all keys)
- The remote module (remote keys)

On the valet key (or if you have a master w/o remote), the transponder chip is embedded in the head of the key.

On the remote key, the transponder is tucked into the remote module. My gut says that whenyou dropped the key and it fell apart that you lost the transponder chip OR that you have taped it together in such a fashion that the immobilizer system is not able to read the chip.

I have attached a picture I stole from eBay which shows the pieces. The transponder chip (which has a red start next to it) is inserted in the remote module where the arrow is pointing. Look at your module and see if it's there. If not, you'll need to replace it and then follow the procedure for the ECU to learn a new key.

 

[Altespace]

Thanks for the reply.
It’s actually a European spec key.

But it makes sense. In tapped the key back together without the electronics inside. I kept the electronics apart from the key. I assume (or I hope) the transponder is stil with the electronics. I will test Theo’s before ordering a new housing from yotamd.

So if I would want to get an extra spare key does it need to be programmed as well?

 

[smoltz]

Thanks for the reply.
It’s actually a European spec key.

But it makes sense. In tapped the key back together without the electronics inside. I kept the electronics apart from the key. I assume (or I hope) the transponder is stil with the electronics. I will test Theo’s before ordering a new housing from yotamd.

So if I would want to get an extra spare key does it need to be programmed as well?

Yes, if you get an extra spare you'll have to program the car to accept it. The instrutions here should work for you, if not search/google... Programming a Transponder Key for 99 TLC - https://forum.ih8mud.com/threads/programming-a-transponder-key-for-99-tlc.14088/

I think you can do it with Techstream too. I have a 2007 and used Techstream for mine.

You'll need a master key though. The spare you have may or may not be a master key. My 2007 LC (US Spec) came with 3 keys. 2 Remote Fob (Master) 1 Grey Non Remote Fob Key (Valet, not master)