Electronic Ignition Key Does Not Work

[harb]

Hello - I have a 2000 E320 with an electronic ignition key. Yesterday, I stopped the car and tried to get back in it to start it and the key won't turn. The car battery is fine. I changed the electronic ignition (FOB) key batteries and still had the same problem. They key would not even lock or unlock the doors.

Finally, I had to call a taxi to go home and get the spare key and the car started just fine. What would cause the key to break? and how can I fix it?

Thank you.

[Check Codes]

They do sometimes die, which it sounds as though yours did. And unless you're an electrical guru, you won't be able to fix it (you could take it apart to see, there is a chip that can come "unsoldered" and with the right equipment and expertise can be resoldered). Otherwise the usual "fix" is replacement. Call all of your local stealers and see who has the best price for a replacement.

Good luck.

[harb]

I opened the FOB case and removed a small white plastic PCB retainer (very gently!). At that point, the PCB slid right out. I visually inspected all components but could not see any loose solder joints or anything unusual. I cleaned it and put it back together but still have the same problem. I read somewhere that they keys are preset to a certain number of starts, after which they stop working (something like 80,000 starts). That seems like a lot of starts! and unlikely to be my problem, I think.

Has someone ever repaired the FOB PCB? And if so, what normally fails on the board?

I am trying everything I can before I have to cough up the big bucks for a new key, not to mention the satisfaction recognized from fixing it myself!

[SHAUNE55]

If you search the threads on here there is a member who repairs key fobs. I think it's darknight, not 100% on that though.

[drkknght]

Originally Posted by harb

I am trying everything I can before I have to cough up the big bucks for a new key, not to mention the satisfaction recognized from fixing it myself!

My feeling exactly, when I figured out how to beat the stealer.

You need to look under a microscopes to see defects at components level.
Send me a pm, I might be able to help.

[98e430sport]

Originally Posted by drkknght

My feeling exactly, when I figured out how to beat the stealer.

You need to look under a microscopes to see defects at components level.
Send me a pm, I might be able to help.

could a faulty key fob also present a no start/start/delayed start? my key upon being inserted is ack'd by the system and does physically turn, however, it has a delayed start, sometimes starts literally on its own, while in the start position, or just wont start at all. when it does start it turns right over nicely, lately this has been very rare. could the key itself, although, it turns and has system ack'd cause a series of no starts/partial starts/delayed starts? thank you in advance!

all the best

[drkknght]

You might want to clean the lense at the tip of the key with alcohol for cleaner signals, less interference.