When I use the main key for the car (Opel Zafira B, 2007, manual), the electronics turn on but the engine won't start. It won't even make a noise as if it was trying to start. With the spare key, however, I can just start the car and drive away without a problem.

Any insights into this issue are appreciated. Thanks.

Edit: thanks for your thoughts. After your suggestions i did get back to the car with both keys and these are the observations:

1) The main key can turn the car on by itself, but only works once every four or five times. When the problem started it could turn the car on at the second try and at some point I thought it was completely broken, but after repeated tries yesterday it was turning on the engine.

2) The couple of times I tried to use the main key with the secondary key near the ignition, the engine turned on at first try. The secondary key still turns the engine on at first try as well

3) the key is not bent and there are no visual signs of problems. I did remove some grime from the key groove with a toothpick, so now it is cleaner. But still it does not turn the engine on reliably.

4) When the key fails to turn on the engine, the yellow warning for "Service Vehicle Soon" shows up.

  • 2
    Is there anything which looks like a security symbol on the dash with the first key? If so, I'd suggest the car has either lost the responder code (doubtful) or the keys transmitter crystal has died. Oct 3, 2016 at 8:24
  • Have you verified multiple times with the spare key and main key?
    – anonymous2
    Oct 3, 2016 at 11:38
  • Is it a smart key with a faub and battery? Oct 4, 2016 at 18:05

2 Answers 2


you have pretty much diagnosed your own problem. The problem is the main key. You need to take the car to a dealership or qualified car locksmith, and they can reset the key code or replace the faulty key. whatever one is the issue. Probably will cost around eighty dollars, but if you lose the other key, you wont regret spending this money!

Cheers Hutch

  • I did bring the car to the dealership with both keys and they tell me that the problem is the chip reader by the steering wheel. Their diagnostic doesn't make much sense to me, hence I'm asking here. They say the replacement of the chip reader would cost about 500 euros. I am not sure if they identified the problem correctly or if they are trying to rip me off.
    – AutoNoob
    Oct 3, 2016 at 10:38
  • 1
    If it starts consistently with one key and not the other, the chip reader is not at fault. One thing you can do is try and start it with the bad key but holding the key that works tight up against the ring around the ignition barrel. If it starts doing this, you definitely have one bad key. Simply ordering a new transponder and having it coded to the car is all that is required. Oct 3, 2016 at 11:56
  • @AutoNoob Find a new dealer. They're trying to unnecessarily place a pretty expensive part when the issue is certainly the key.
    – 3Dave
    Oct 4, 2016 at 14:12

Assuming that you have tried multiple times to start your car with both keys and it is consistently one key that works and another that does not, you can affirmatively say that there is a difference between the two keys. (Not rocket science. :) )

As user22838 said, replacing the key could fix the problem. That being said, however, a physical inspection of the key could reveal the problem and a possible workaround solution. Is the key bent? Is it worn? Compare the two keys for physical differences.

If the key is bent, a very careful pressure applied with a soft material (ie., wood, not metal) could bring it back straight and put it in functioning order.

You could also check out this article for more information and tips.

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